Simplify ungzip implementation per review feedback

- Remove manual gzip header parsing - libdeflate handles all format details
- Rename linearize_chunked_content to build_input_buffer and free chunks as we copy
- Add output chunking to split large decompressed data into 1MB chunks
- Add comment explaining libdeflate's whole-buffer requirement
- Use better initial size heuristic based on compression ratio

Co-authored-by: nyh <584227+nyh@users.noreply.github.com>

.github/CODEOWNERS

@@ -1,5 +1,5 @@
 # AUTH
-auth/* @nuivall
+auth/* @nuivall @ptrsmrn
 
 # CACHE
 row_cache* @tgrabiec
@@ -25,11 +25,11 @@ compaction/* @raphaelsc
 transport/*
 
 # CQL QUERY LANGUAGE
-cql3/* @tgrabiec @nuivall
+cql3/* @tgrabiec @nuivall @ptrsmrn
 
 # COUNTERS
-counters* @nuivall
-tests/counter_test* @nuivall
+counters* @nuivall @ptrsmrn
+tests/counter_test* @nuivall @ptrsmrn
 
 # DOCS
 docs/* @annastuchlik @tzach
@@ -57,6 +57,7 @@ repair/* @tgrabiec @asias
 
 # SCHEMA MANAGEMENT
 db/schema_tables* @tgrabiec
+db/legacy_schema_migrator* @tgrabiec
 service/migration* @tgrabiec
 schema* @tgrabiec
 

.github/copilot-instructions.md

@@ -1,86 +0,0 @@
-# ScyllaDB Development Instructions
-
-## Project Context
-High-performance distributed NoSQL database. Core values: performance, correctness, readability.
-
-## Build System
-
-### Modern Build (configure.py + ninja)
-```bash
-# Configure (run once per mode, or when switching modes)
-./configure.py --mode=<mode>  # mode: dev, debug, release, sanitize
-
-# Build everything
-ninja <mode>-build  # e.g., ninja dev-build
-
-# Build Scylla binary only (sufficient for Python integration tests)
-ninja build/<mode>/scylla
-
-# Build specific test
-ninja build/<mode>/test/boost/<test_name>
-```
-
-## Running Tests
-
-### C++ Unit Tests
-```bash
-# Run all tests in a file
-./test.py --mode=<mode> test/<suite>/<test_name>.cc
-
-# Run a single test case from a file
-./test.py --mode=<mode> test/<suite>/<test_name>.cc::<test_case_name>
-
-# Examples
-./test.py --mode=dev test/boost/memtable_test.cc
-./test.py --mode=dev test/raft/raft_server_test.cc::test_check_abort_on_client_api
-```
-
-**Important:** 
-- Use full path with `.cc` extension (e.g., `test/boost/test_name.cc`, not `boost/test_name`)
-- To run a single test case, append `::<test_case_name>` to the file path
-- If you encounter permission issues with cgroup metric gathering, add `--no-gather-metrics` flag
-
-**Rebuilding Tests:**
-- test.py does NOT automatically rebuild when test source files are modified
-- Many tests are part of composite binaries (e.g., `combined_tests` in test/boost contains multiple test files)
-- To find which binary contains a test, check `configure.py` in the repository root (primary source) or `test/<suite>/CMakeLists.txt`
-- To rebuild a specific test binary: `ninja build/<mode>/test/<suite>/<binary_name>`
-- Examples: 
-  - `ninja build/dev/test/boost/combined_tests` (contains group0_voter_calculator_test.cc and others)
-  - `ninja build/dev/test/raft/replication_test` (standalone Raft test)
-
-### Python Integration Tests
-```bash
-# Only requires Scylla binary (full build usually not needed)
-ninja build/<mode>/scylla
-
-# Run all tests in a file
-./test.py --mode=<mode> <test_path>
-
-# Run a single test case from a file
-./test.py --mode=<mode> <test_path>::<test_function_name>
-
-# Examples
-./test.py --mode=dev alternator/
-./test.py --mode=dev cluster/test_raft_voters::test_raft_limited_voters_retain_coordinator
-
-# Optional flags
-./test.py --mode=dev cluster/test_raft_no_quorum -v  # Verbose output
-./test.py --mode=dev cluster/test_raft_no_quorum --repeat 5  # Repeat test 5 times
-```
-
-**Important:**
-- Use path without `.py` extension (e.g., `cluster/test_raft_no_quorum`, not `cluster/test_raft_no_quorum.py`)
-- To run a single test case, append `::<test_function_name>` to the file path
-- Add `-v` for verbose output
-- Add `--repeat <num>` to repeat a test multiple times
-- After modifying C++ source files, only rebuild the Scylla binary for Python tests - building the entire repository is unnecessary
-
-## Code Philosophy
-- Performance matters in hot paths (data read/write, inner loops)
-- Self-documenting code through clear naming
-- Comments explain "why", not "what"
-- Prefer standard library over custom implementations
-- Strive for simplicity and clarity, add complexity only when clearly justified
-- Question requests: don't blindly implement requests - evaluate trade-offs, identify issues, and suggest better alternatives when appropriate
-- Consider different approaches, weigh pros and cons, and recommend the best fit for the specific context

.github/instructions/cpp.instructions.md

@@ -1,115 +0,0 @@
----
-applyTo: "**/*.{cc,hh}"
----
-
-# C++ Guidelines
-
-**Important:** Always match the style and conventions of existing code in the file and directory.
-
-## Memory Management
-- Prefer stack allocation whenever possible
-- Use `std::unique_ptr` by default for dynamic allocations
-- `new`/`delete` are forbidden (use RAII)
-- Use `seastar::lw_shared_ptr` or `seastar::shared_ptr` for shared ownership within same shard
-- Use `seastar::foreign_ptr` for cross-shard sharing
-- Avoid `std::shared_ptr` except when interfacing with external C++ APIs
-- Avoid raw pointers except for non-owning references or C API interop
-
-## Seastar Asynchronous Programming
-- Use `seastar::future<T>` for all async operations
-- Prefer coroutines (`co_await`, `co_return`) over `.then()` chains for readability
-- Coroutines are preferred over `seastar::do_with()` for managing temporary state
-- In hot paths where futures are ready, continuations may be more efficient than coroutines
-- Chain futures with `.then()`, don't block with `.get()` (unless in `seastar::thread` context)
-- All I/O must be asynchronous (no blocking calls)
-- Use `seastar::gate` for shutdown coordination
-- Use `seastar::semaphore` for resource limiting (not `std::mutex`)
-- Break long loops with `maybe_yield()` to avoid reactor stalls
-
-## Coroutines
-```cpp
-seastar::future<T> func() {
-    auto result = co_await async_operation();
-    co_return result;
-}
-```
-
-## Error Handling
-- Throw exceptions for errors (futures propagate them automatically)
-- In data path: avoid exceptions, use `std::expected` (or `boost::outcome`) instead
-- Use standard exceptions (`std::runtime_error`, `std::invalid_argument`)
-- Database-specific: throw appropriate schema/query exceptions
-
-## Performance
-- Pass large objects by `const&` or `&&` (move semantics)
-- Use `std::string_view` for non-owning string references
-- Avoid copies: prefer move semantics
-- Use `utils::chunked_vector` instead of `std::vector` for large allocations (>128KB)
-- Minimize dynamic allocations in hot paths
-
-## Database-Specific Types
-- Use `schema_ptr` for schema references
-- Use `mutation` and `mutation_partition` for data modifications
-- Use `partition_key` and `clustering_key` for keys
-- Use `api::timestamp_type` for database timestamps
-- Use `gc_clock` for garbage collection timing
-
-## Style
-- C++23 standard (prefer modern features, especially coroutines)
-- Use `auto` when type is obvious from RHS
-- Avoid `auto` when it obscures the type
-- Use range-based for loops: `for (const auto& item : container)`
-- Use standard algorithms when they clearly simplify code (e.g., replacing 10-line loops)
-- Avoid chaining multiple algorithms if a straightforward loop is clearer
-- Mark functions and variables `const` whenever possible
-- Use scoped enums: `enum class` (not unscoped `enum`)
-
-## Headers
-- Use `#pragma once`
-- Include order: own header, C++ std, Seastar, Boost, project headers
-- Forward declare when possible
-- Never `using namespace` in headers (exception: `using namespace seastar` is globally available via `seastarx.hh`)
-
-## Documentation
-- Public APIs require clear documentation
-- Implementation details should be self-evident from code
-- Use `///` or Doxygen `/** */` for public documentation, `//` for implementation notes - follow the existing style
-
-## Naming
-- `snake_case` for most identifiers (classes, functions, variables, namespaces)
-- Template parameters: `CamelCase` (e.g., `template<typename ValueType>`)
-- Member variables: prefix with `_` (e.g., `int _count;`)
-- Structs (value-only): no `_` prefix on members
-- Constants and `constexpr`: `snake_case` (e.g., `static constexpr int max_size = 100;`)
-- Files: `.hh` for headers, `.cc` for source
-
-## Formatting
-- 4 spaces indentation, never tabs
-- Opening braces on same line as control structure (except namespaces)
-- Space after keywords: `if (`, `while (`, `return `
-- Whitespace around operators matches precedence: `*a + *b` not `* a+* b`
-- Line length: keep reasonable (<160 chars), use continuation lines with double indent if needed
-- Brace all nested scopes, even single statements
-- Minimal patches: only format code you modify, never reformat entire files
-
-## Logging
-- Use structured logging with appropriate levels: DEBUG, INFO, WARN, ERROR
-- Include context in log messages (e.g., request IDs)
-- Never log sensitive data (credentials, PII)
-
-## Forbidden
-- `malloc`/`free`
-- `printf` family (use logging or fmt)
-- Raw pointers for ownership
-- `using namespace` in headers
-- Blocking operations: `std::sleep`, `std::read`, `std::mutex` (use Seastar equivalents)
-- `std::atomic` (reserved for very special circumstances only)
-- Macros (use `inline`, `constexpr`, or templates instead)
-
-## Testing
-When modifying existing code, follow TDD: create/update test first, then implement.
-- Examine existing tests for style and structure
-- Use Boost.Test framework
-- Use `SEASTAR_THREAD_TEST_CASE` for Seastar asynchronous tests
-- Aim for high code coverage, especially for new features and bug fixes
-- Maintain bisectability: all tests must pass in every commit. Mark failing tests with `BOOST_FAIL()` or similar, then fix in subsequent commit

.github/instructions/python.instructions.md

@@ -1,51 +0,0 @@
----
-applyTo: "**/*.py"
----
-
-# Python Guidelines
-
-**Important:** Match existing code style. Some directories (like `test/cqlpy` and `test/alternator`) prefer simplicity over type hints and docstrings.
-
-## Style
-- Follow PEP 8
-- Use type hints for function signatures (unless directory style omits them)
-- Use f-strings for formatting
-- Line length: 160 characters max
-- 4 spaces for indentation
-
-## Imports
-Order: standard library, third-party, local imports
-```python
-import os
-import sys
-
-import pytest
-from cassandra.cluster import Cluster
-
-from test.utils import setup_keyspace
-```
-
-Never use `from module import *`
-
-## Documentation
-All public functions/classes need docstrings (unless the current directory conventions omit them):
-```python
-def my_function(arg1: str, arg2: int) -> bool:
-    """
-    Brief summary of function purpose.
-
-    Args:
-        arg1: Description of first argument.
-        arg2: Description of second argument.
-
-    Returns:
-        Description of return value.
-    """
-    pass
-```
-
-## Testing Best Practices
-- Maintain bisectability: all tests must pass in every commit
-- Mark currently-failing tests with `@pytest.mark.xfail`, unmark when fixed
-- Use descriptive names that convey intent
-- Docstrings/comments should explain what the test verifies and why, and if it reproduces a specific issue or how it fits into the larger test suite

.github/scripts/auto-backport.py

@@ -62,7 +62,7 @@ def create_pull_request(repo, new_branch_name, base_branch_name, pr, backport_pr
         if is_draft:
             labels_to_add.append("conflicts")
             pr_comment = f"@{pr.user.login} - This PR was marked as draft because it has conflicts\n"
-            pr_comment += "Please resolve them and remove the 'conflicts' label. The PR will be made ready for review automatically."
+            pr_comment += "Please resolve them and mark this PR as ready for review"
             backport_pr.create_issue_comment(pr_comment)
         
         # Apply all labels at once if we have any

.github/workflows/backport-pr-fixes-validation.yaml

@@ -18,7 +18,7 @@ jobs:
             
             // Regular expression pattern to check for "Fixes" prefix
             // Adjusted to dynamically insert the repository full name
-            const pattern = `Fixes:? ((?:#|${repo.replace('/', '\\/')}#|https://github\\.com/${repo.replace('/', '\\/')}/issues/)(\\d+)|([A-Z]+-\\d+))`;
+            const pattern = `Fixes:? (?:#|${repo.replace('/', '\\/')}#|https://github\\.com/${repo.replace('/', '\\/')}/issues/)(\\d+)`;
             const regex = new RegExp(pattern);
             
             if (!regex.test(body)) {

.github/workflows/docs-validate-metrics.yml

@@ -1,34 +0,0 @@
-name: Docs / Validate metrics
-
-on:
-  pull_request:
-    branches:
-      - master
-      - enterprise
-    paths:
-      - '**/*.cc'
-      - 'scripts/metrics-config.yml' 
-      - 'scripts/get_description.py'
-      - 'docs/_ext/scylladb_metrics.py'
-
-jobs:
-  validate-metrics:
-    runs-on: ubuntu-latest
-    name: Check metrics documentation coverage
-    
-    steps:
-    - name: Checkout code
-      uses: actions/checkout@v4
-      with:
-        submodules: true
-      
-    - name: Set up Python
-      uses: actions/setup-python@v6
-      with:
-        python-version: '3.10'
-        
-    - name: Install dependencies
-      run: pip install PyYAML
-        
-    - name: Validate metrics
-      run: python3 scripts/get_description.py --validate -c scripts/metrics-config.yml

.github/workflows/trigger-scylla-ci.yaml

@@ -3,13 +3,10 @@ name: Trigger Scylla CI Route
 on:
   issue_comment:
     types: [created]
-  pull_request_target:
-    types:
-      - unlabeled
 
 jobs:
   trigger-jenkins:
-    if: (github.event.comment.user.login != 'scylladbbot' && contains(github.event.comment.body, '@scylladbbot') && contains(github.event.comment.body, 'trigger-ci')) || github.event.label.name == 'conflicts'
+    if: github.event.comment.user.login != 'scylladbbot' && contains(github.event.comment.body, '@scylladbbot') && contains(github.event.comment.body, 'trigger-ci')
     runs-on: ubuntu-latest
     steps:
       - name: Trigger Scylla-CI-Route Jenkins Job

CMakeLists.txt

@@ -116,7 +116,6 @@ list(APPEND absl_cxx_flags
 if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
     list(APPEND ABSL_GCC_FLAGS ${absl_cxx_flags})
 elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
-    list(APPEND absl_cxx_flags "-Wno-deprecated-builtins")
     list(APPEND ABSL_LLVM_FLAGS ${absl_cxx_flags})
 endif()
 set(ABSL_DEFAULT_LINKOPTS
@@ -164,45 +163,7 @@ file(MAKE_DIRECTORY "${scylla_gen_build_dir}")
 include(add_version_library)
 generate_scylla_version()
 
-option(Scylla_USE_PRECOMPILED_HEADER "Use precompiled header for Scylla" ON)
-add_library(scylla-precompiled-header STATIC exported_templates.cc)
-target_link_libraries(scylla-precompiled-header PRIVATE
-    absl::headers
-    absl::btree
-    absl::hash
-    absl::raw_hash_set
-    Seastar::seastar
-    Snappy::snappy
-    systemd
-    ZLIB::ZLIB
-    lz4::lz4_static
-    zstd::zstd_static)
-if (Scylla_USE_PRECOMPILED_HEADER)
-  set(Scylla_USE_PRECOMPILED_HEADER_USE ON)
-  find_program(DISTCC_EXEC NAMES distcc OPTIONAL)
-  if (DISTCC_EXEC)
-    if(DEFINED ENV{DISTCC_HOSTS})
-      set(Scylla_USE_PRECOMPILED_HEADER_USE OFF)
-      message(STATUS "Disabling precompiled header usage because distcc exists and DISTCC_HOSTS is set, assuming you're using distributed compilation.")
-    else()
-      file(REAL_PATH "~/.distcc/hosts" DIST_CC_HOSTS_PATH EXPAND_TILDE)
-      if (EXISTS ${DIST_CC_HOSTS_PATH})
-        set(Scylla_USE_PRECOMPILED_HEADER_USE OFF)
-        message(STATUS "Disabling precompiled header usage because distcc and ~/.distcc/hosts exists, assuming you're using distributed compilation.")
-      endif()
-    endif()
-  endif()
-  if (Scylla_USE_PRECOMPILED_HEADER_USE)
-    message(STATUS "Using precompiled header for Scylla - remember to add `sloppiness = pch_defines,time_macros` to ccache.conf, if you're using ccache.")
-    target_precompile_headers(scylla-precompiled-header PRIVATE "stdafx.hh")
-    target_compile_definitions(scylla-precompiled-header PRIVATE SCYLLA_USE_PRECOMPILED_HEADER)
-  endif()
-else()
-  set(Scylla_USE_PRECOMPILED_HEADER_USE OFF)
-endif()
-
 add_library(scylla-main STATIC)
-
 target_sources(scylla-main
   PRIVATE
     absl-flat_hash_map.cc
@@ -247,7 +208,6 @@ target_link_libraries(scylla-main
     ZLIB::ZLIB
     lz4::lz4_static
     zstd::zstd_static
-    scylla-precompiled-header
 )
 
 option(Scylla_CHECK_HEADERS

alternator/CMakeLists.txt

@@ -34,8 +34,5 @@ target_link_libraries(alternator
     idl
     absl::headers)
 
-if (Scylla_USE_PRECOMPILED_HEADER_USE)
-  target_precompile_headers(alternator REUSE_FROM scylla-precompiled-header)
-endif()
 check_headers(check-headers alternator
   GLOB_RECURSE ${CMAKE_CURRENT_SOURCE_DIR}/*.hh)

alternator/conditions.cc

@@ -42,7 +42,7 @@ comparison_operator_type get_comparison_operator(const rjson::value& comparison_
     if (!comparison_operator.IsString()) {
         throw api_error::validation(fmt::format("Invalid comparison operator definition {}", rjson::print(comparison_operator)));
     }
-    std::string op = rjson::to_string(comparison_operator);
+    std::string op = comparison_operator.GetString();
     auto it = ops.find(op);
     if (it == ops.end()) {
         throw api_error::validation(fmt::format("Unsupported comparison operator {}", op));
@@ -377,8 +377,8 @@ bool check_compare(const rjson::value* v1, const rjson::value& v2, const Compara
         return cmp(unwrap_number(*v1, cmp.diagnostic), unwrap_number(v2, cmp.diagnostic));
     }
     if (kv1.name == "S") {
-        return cmp(rjson::to_string_view(kv1.value),
-                   rjson::to_string_view(kv2.value));
+        return cmp(std::string_view(kv1.value.GetString(), kv1.value.GetStringLength()),
+                   std::string_view(kv2.value.GetString(), kv2.value.GetStringLength()));
     }
     if (kv1.name == "B") {
         auto d_kv1 = unwrap_bytes(kv1.value, v1_from_query);
@@ -470,9 +470,9 @@ static bool check_BETWEEN(const rjson::value* v, const rjson::value& lb, const r
         return check_BETWEEN(unwrap_number(*v, diag), unwrap_number(lb, diag), unwrap_number(ub, diag), bounds_from_query);
     }
     if (kv_v.name == "S") {
-        return check_BETWEEN(rjson::to_string_view(kv_v.value),
-                             rjson::to_string_view(kv_lb.value),
-                             rjson::to_string_view(kv_ub.value),
+        return check_BETWEEN(std::string_view(kv_v.value.GetString(), kv_v.value.GetStringLength()),
+                             std::string_view(kv_lb.value.GetString(), kv_lb.value.GetStringLength()),
+                             std::string_view(kv_ub.value.GetString(), kv_ub.value.GetStringLength()),
                              bounds_from_query);
     }
     if (kv_v.name == "B") {

alternator/consumed_capacity.cc

@@ -8,8 +8,6 @@
 
 #include "consumed_capacity.hh"
 #include "error.hh"
-#include "utils/rjson.hh"
-#include <fmt/format.h>
 
 namespace alternator {
 
@@ -34,12 +32,12 @@ bool consumed_capacity_counter::should_add_capacity(const rjson::value& request)
     if (!return_consumed->IsString()) {
         throw api_error::validation("Non-string ReturnConsumedCapacity field in request");
     }
-    std::string_view consumed = rjson::to_string_view(*return_consumed);
+    std::string consumed = return_consumed->GetString();
     if (consumed == "INDEXES") {
         throw api_error::validation("INDEXES consumed capacity is not supported");
     }
     if (consumed != "TOTAL") {
-        throw api_error::validation(fmt::format("Unknown consumed capacity {}", consumed));
+        throw api_error::validation("Unknown consumed capacity "+ consumed);
     }
     return true;
 }

alternator/executor.cc

@@ -419,7 +419,7 @@ static std::optional<std::string> find_table_name(const rjson::value& request) {
     if (!table_name_value->IsString()) {
         throw api_error::validation("Non-string TableName field in request");
     }
-    std::string table_name = rjson::to_string(*table_name_value);
+    std::string table_name = table_name_value->GetString();
     return table_name;
 }
 
@@ -546,7 +546,7 @@ get_table_or_view(service::storage_proxy& proxy, const rjson::value& request) {
             // does exist but the index does not (ValidationException).
             if (proxy.data_dictionary().has_schema(keyspace_name, orig_table_name)) {
                 throw api_error::validation(
-                    fmt::format("Requested resource not found: Index '{}' for table '{}'", rjson::to_string_view(*index_name), orig_table_name));
+                    fmt::format("Requested resource not found: Index '{}' for table '{}'", index_name->GetString(), orig_table_name));
             } else {
                 throw api_error::resource_not_found(
                     fmt::format("Requested resource not found: Table: {} not found", orig_table_name));
@@ -587,7 +587,7 @@ static std::string get_string_attribute(const rjson::value& value, std::string_v
         throw api_error::validation(fmt::format("Expected string value for attribute {}, got: {}",
                 attribute_name, value));
     }
-    return rjson::to_string(*attribute_value);
+    return std::string(attribute_value->GetString(), attribute_value->GetStringLength());
 }
 
 // Convenience function for getting the value of a boolean attribute, or a
@@ -888,7 +888,7 @@ future<executor::request_return_type> executor::describe_table(client_state& cli
 
     schema_ptr schema = get_table(_proxy, request);
     get_stats_from_schema(_proxy, *schema)->api_operations.describe_table++;
-    tracing::add_alternator_table_name(trace_state, schema->cf_name());
+    tracing::add_table_name(trace_state, schema->ks_name(), schema->cf_name());
 
     rjson::value table_description = co_await fill_table_description(schema, table_status::active, _proxy, client_state, trace_state, permit);
     rjson::value response = rjson::empty_object();
@@ -989,7 +989,7 @@ future<executor::request_return_type> executor::delete_table(client_state& clien
     std::string table_name = get_table_name(request);
 
     std::string keyspace_name = executor::KEYSPACE_NAME_PREFIX + table_name;
-    tracing::add_alternator_table_name(trace_state, table_name);
+    tracing::add_table_name(trace_state, keyspace_name, table_name);
     auto& p = _proxy.container();
 
     schema_ptr schema = get_table(_proxy, request);
@@ -1008,8 +1008,8 @@ future<executor::request_return_type> executor::delete_table(client_state& clien
                 throw api_error::resource_not_found(fmt::format("Requested resource not found: Table: {} not found", table_name));
             }
 
-            auto m = co_await service::prepare_column_family_drop_announcement(p.local(), keyspace_name, table_name, group0_guard.write_timestamp(), service::drop_views::yes);
-            auto m2 = co_await service::prepare_keyspace_drop_announcement(p.local(), keyspace_name, group0_guard.write_timestamp());
+            auto m = co_await service::prepare_column_family_drop_announcement(_proxy, keyspace_name, table_name, group0_guard.write_timestamp(), service::drop_views::yes);
+            auto m2 = co_await service::prepare_keyspace_drop_announcement(_proxy, keyspace_name, group0_guard.write_timestamp());
 
             std::move(m2.begin(), m2.end(), std::back_inserter(m));
 
@@ -1080,8 +1080,8 @@ static void add_column(schema_builder& builder, const std::string& name, const r
     }
     for (auto it = attribute_definitions.Begin(); it != attribute_definitions.End(); ++it) {
         const rjson::value& attribute_info = *it;
-        if (rjson::to_string_view(attribute_info["AttributeName"]) == name) {
-            std::string_view type = rjson::to_string_view(attribute_info["AttributeType"]);
+        if (attribute_info["AttributeName"].GetString() == name) {
+            auto type = attribute_info["AttributeType"].GetString();
             data_type dt = parse_key_type(type);
             if (computed_column) {
                 // Computed column for GSI (doesn't choose a real column as-is
@@ -1116,7 +1116,7 @@ static std::pair<std::string, std::string> parse_key_schema(const rjson::value&
         throw api_error::validation("First element of KeySchema must be an object");
     }
     const rjson::value *v = rjson::find((*key_schema)[0], "KeyType");
-    if (!v || !v->IsString() || rjson::to_string_view(*v) != "HASH") {
+    if (!v || !v->IsString() || v->GetString() != std::string("HASH")) {
         throw api_error::validation("First key in KeySchema must be a HASH key");
     }
     v = rjson::find((*key_schema)[0], "AttributeName");
@@ -1124,14 +1124,14 @@ static std::pair<std::string, std::string> parse_key_schema(const rjson::value&
         throw api_error::validation("First key in KeySchema must have string AttributeName");
     }
     validate_attr_name_length(supplementary_context, v->GetStringLength(), true, "HASH key in KeySchema - ");
-    std::string hash_key = rjson::to_string(*v);
+    std::string hash_key = v->GetString();
     std::string range_key;
     if (key_schema->Size() == 2) {
         if (!(*key_schema)[1].IsObject()) {
             throw api_error::validation("Second element of KeySchema must be an object");
         }
         v = rjson::find((*key_schema)[1], "KeyType");
-        if (!v || !v->IsString() || rjson::to_string_view(*v) != "RANGE") {
+        if (!v || !v->IsString() || v->GetString() != std::string("RANGE")) {
             throw api_error::validation("Second key in KeySchema must be a RANGE key");
         }
         v = rjson::find((*key_schema)[1], "AttributeName");
@@ -1583,7 +1583,7 @@ static future<executor::request_return_type> create_table_on_shard0(service::cli
     std::unordered_set<std::string> unused_attribute_definitions =
         validate_attribute_definitions("", *attribute_definitions);
 
-    tracing::add_alternator_table_name(trace_state, table_name);
+    tracing::add_table_name(trace_state, keyspace_name, table_name);
 
     schema_builder builder(keyspace_name, table_name);
     auto [hash_key, range_key] = parse_key_schema(request, "");
@@ -1865,10 +1865,10 @@ future<executor::request_return_type> executor::create_table(client_state& clien
     _stats.api_operations.create_table++;
     elogger.trace("Creating table {}", request);
 
-    co_return co_await _mm.container().invoke_on(0, [&, tr = tracing::global_trace_state_ptr(trace_state), request = std::move(request), &sp = _proxy.container(), &g = _gossiper.container(), &e = this->container(), client_state_other_shard = client_state.move_to_other_shard(), enforce_authorization = bool(_enforce_authorization), warn_authorization = bool(_warn_authorization)]
+    co_return co_await _mm.container().invoke_on(0, [&, tr = tracing::global_trace_state_ptr(trace_state), request = std::move(request), &sp = _proxy.container(), &g = _gossiper.container(), client_state_other_shard = client_state.move_to_other_shard(), enforce_authorization = bool(_enforce_authorization), warn_authorization = bool(_warn_authorization)]
                                         (service::migration_manager& mm) mutable -> future<executor::request_return_type> {
         const db::tablets_mode_t::mode tablets_mode = _proxy.data_dictionary().get_config().tablets_mode_for_new_keyspaces(); // type cast
-        co_return co_await create_table_on_shard0(client_state_other_shard.get(), tr, std::move(request), sp.local(), mm, g.local(), enforce_authorization, warn_authorization, e.local()._stats, std::move(tablets_mode));
+        co_return co_await create_table_on_shard0(client_state_other_shard.get(), tr, std::move(request), sp.local(), mm, g.local(), enforce_authorization, warn_authorization, _stats, std::move(tablets_mode));
     });
 }
 
@@ -1887,8 +1887,8 @@ future<executor::request_return_type> executor::create_table(client_state& clien
         std::string def_type = type_to_string(def.type);
         for (auto it = attribute_definitions.Begin(); it != attribute_definitions.End(); ++it) {
             const rjson::value& attribute_info = *it;
-            if (rjson::to_string_view(attribute_info["AttributeName"]) == def.name_as_text()) {
-                std::string_view type = rjson::to_string_view(attribute_info["AttributeType"]);
+            if (attribute_info["AttributeName"].GetString() == def.name_as_text()) {
+                auto type = attribute_info["AttributeType"].GetString();
                 if (type != def_type) {
                     throw api_error::validation(fmt::format("AttributeDefinitions redefined {} to {} already a key attribute of type {} in this table", def.name_as_text(), type, def_type));
                 }
@@ -1930,7 +1930,7 @@ future<executor::request_return_type> executor::update_table(client_state& clien
 
             schema_ptr tab = get_table(p.local(), request);
 
-            tracing::add_alternator_table_name(gt, tab->cf_name());
+            tracing::add_table_name(gt, tab->ks_name(), tab->cf_name());
 
             // the ugly but harmless conversion to string_view here is because
             // Seastar's sstring is missing a find(std::string_view) :-()
@@ -2223,12 +2223,12 @@ void validate_value(const rjson::value& v, const char* caller) {
 
 // The put_or_delete_item class builds the mutations needed by the PutItem and
 // DeleteItem operations - either as stand-alone commands or part of a list
-// of commands in BatchWriteItem.
+// of commands in BatchWriteItems.
 // put_or_delete_item splits each operation into two stages: Constructing the
 // object parses and validates the user input (throwing exceptions if there
 // are input errors). Later, build() generates the actual mutation, with a
 // specified timestamp. This split is needed because of the peculiar needs of
-// BatchWriteItem and LWT. BatchWriteItem needs all parsing to happen before
+// BatchWriteItems and LWT. BatchWriteItems needs all parsing to happen before
 // any writing happens (if one of the commands has an error, none of the
 // writes should be done). LWT makes it impossible for the parse step to
 // generate "mutation" objects, because the timestamp still isn't known.
@@ -2362,7 +2362,7 @@ put_or_delete_item::put_or_delete_item(const rjson::value& item, schema_ptr sche
     _cells = std::vector<cell>();
     _cells->reserve(item.MemberCount());
     for (auto it = item.MemberBegin(); it != item.MemberEnd(); ++it) {
-        bytes column_name = to_bytes(rjson::to_string_view(it->name));
+        bytes column_name = to_bytes(it->name.GetString());
         validate_value(it->value, "PutItem");
         const column_definition* cdef = find_attribute(*schema, column_name);
         validate_attr_name_length("", column_name.size(), cdef && cdef->is_primary_key());
@@ -2624,14 +2624,14 @@ std::optional<service::cas_shard> rmw_operation::shard_for_execute(bool needs_re
 // Build the return value from the different RMW operations (UpdateItem,
 // PutItem, DeleteItem). All these return nothing by default, but can
 // optionally return Attributes if requested via the ReturnValues option.
-static executor::request_return_type rmw_operation_return(rjson::value&& attributes, const consumed_capacity_counter& consumed_capacity, uint64_t& metric) {
+static future<executor::request_return_type> rmw_operation_return(rjson::value&& attributes, const consumed_capacity_counter& consumed_capacity, uint64_t& metric) {
     rjson::value ret = rjson::empty_object();
     consumed_capacity.add_consumed_capacity_to_response_if_needed(ret);
     metric += consumed_capacity.get_consumed_capacity_units();
     if (!attributes.IsNull()) {
         rjson::add(ret, "Attributes", std::move(attributes));
     }
-    return rjson::print(std::move(ret));
+    return make_ready_future<executor::request_return_type>(rjson::print(std::move(ret)));
 }
 
 static future<std::unique_ptr<rjson::value>> get_previous_item(
@@ -2697,10 +2697,7 @@ future<executor::request_return_type> rmw_operation::execute(service::storage_pr
         stats& global_stats,
         stats& per_table_stats,
         uint64_t& wcu_total) {
-    auto cdc_opts = cdc::per_request_options{
-        .alternator = true,
-        .alternator_streams_increased_compatibility = schema()->cdc_options().enabled() && proxy.data_dictionary().get_config().alternator_streams_increased_compatibility(),
-    };
+    auto cdc_opts = cdc::per_request_options{};
     if (needs_read_before_write) {
         if (_write_isolation == write_isolation::FORBID_RMW) {
             throw api_error::validation("Read-modify-write operations are disabled by 'forbid_rmw' write isolation policy. Refer to https://github.com/scylladb/scylla/blob/master/docs/alternator/alternator.md#write-isolation-policies for more information.");
@@ -2739,13 +2736,13 @@ future<executor::request_return_type> rmw_operation::execute(service::storage_pr
     auto read_command = needs_read_before_write ?
             previous_item_read_command(proxy, schema(), _ck, selection) :
             nullptr;
-    return proxy.cas(schema(), std::move(*cas_shard), *this, read_command, to_partition_ranges(*schema(), _pk),
+    return proxy.cas(schema(), std::move(*cas_shard), shared_from_this(), read_command, to_partition_ranges(*schema(), _pk),
             {timeout, std::move(permit), client_state, trace_state},
             db::consistency_level::LOCAL_SERIAL, db::consistency_level::LOCAL_QUORUM, timeout, timeout, true, std::move(cdc_opts)).then([this, read_command, &wcu_total] (bool is_applied) mutable {
         if (!is_applied) {
             return make_ready_future<executor::request_return_type>(api_error::conditional_check_failed("The conditional request failed", std::move(_return_attributes)));
         }
-        return make_ready_future<executor::request_return_type>(rmw_operation_return(std::move(_return_attributes), _consumed_capacity, wcu_total));
+        return rmw_operation_return(std::move(_return_attributes), _consumed_capacity, wcu_total);
     });
 }
 
@@ -2783,10 +2780,10 @@ static void verify_all_are_used(const rjson::value* field,
         return;
     }
     for (auto it = field->MemberBegin(); it != field->MemberEnd(); ++it) {
-        if (!used.contains(rjson::to_string(it->name))) {
+        if (!used.contains(it->name.GetString())) {
             throw api_error::validation(
                 format("{} has spurious '{}', not used in {}",
-                    field_name, rjson::to_string_view(it->name), operation));
+                    field_name, it->name.GetString(), operation));
         }
     }
 }
@@ -2859,7 +2856,7 @@ future<executor::request_return_type> executor::put_item(client_state& client_st
     elogger.trace("put_item {}", request);
 
     auto op = make_shared<put_item_operation>(*_parsed_expression_cache, _proxy, std::move(request));
-    tracing::add_alternator_table_name(trace_state, op->schema()->cf_name());
+    tracing::add_table_name(trace_state, op->schema()->ks_name(), op->schema()->cf_name());
     const bool needs_read_before_write = op->needs_read_before_write();
 
     co_await verify_permission(_enforce_authorization, _warn_authorization, client_state, op->schema(), auth::permission::MODIFY, _stats);
@@ -2963,7 +2960,7 @@ future<executor::request_return_type> executor::delete_item(client_state& client
 
     auto op = make_shared<delete_item_operation>(*_parsed_expression_cache, _proxy, std::move(request));
     lw_shared_ptr<stats> per_table_stats = get_stats_from_schema(_proxy, *(op->schema()));
-    tracing::add_alternator_table_name(trace_state, op->schema()->cf_name());
+    tracing::add_table_name(trace_state, op->schema()->ks_name(), op->schema()->cf_name());
     const bool needs_read_before_write = _proxy.data_dictionary().get_config().alternator_force_read_before_write() || op->needs_read_before_write();
 
     co_await verify_permission(_enforce_authorization, _warn_authorization, client_state, op->schema(), auth::permission::MODIFY, _stats);
@@ -3000,7 +2997,7 @@ future<executor::request_return_type> executor::delete_item(client_state& client
 }
 
 static schema_ptr get_table_from_batch_request(const service::storage_proxy& proxy, const rjson::value::ConstMemberIterator& batch_request) {
-    sstring table_name = rjson::to_sstring(batch_request->name); // JSON keys are always strings
+    sstring table_name = batch_request->name.GetString(); // JSON keys are always strings
     try {
         return proxy.data_dictionary().find_schema(sstring(executor::KEYSPACE_NAME_PREFIX) + table_name, table_name);
     } catch(data_dictionary::no_such_column_family&) {
@@ -3026,20 +3023,17 @@ struct primary_key_equal {
 };
 
 // This is a cas_request subclass for applying given put_or_delete_items to
-// one partition using LWT as part as BatchWriteItem. This is a write-only
+// one partition using LWT as part as BatchWriteItems. This is a write-only
 // operation, not needing the previous value of the item (the mutation to be
 // done is known prior to starting the operation). Nevertheless, we want to
 // do this mutation via LWT to ensure that it is serialized with other LWT
 // mutations to the same partition.
-// 
-// The std::vector<put_or_delete_item> must remain alive until the
-// storage_proxy::cas() future is resolved.
 class put_or_delete_item_cas_request : public service::cas_request {
     schema_ptr schema;
-    const std::vector<put_or_delete_item>& _mutation_builders;
+    std::vector<put_or_delete_item> _mutation_builders;
 public:
-    put_or_delete_item_cas_request(schema_ptr s, const std::vector<put_or_delete_item>& b) :
-        schema(std::move(s)), _mutation_builders(b) { }
+    put_or_delete_item_cas_request(schema_ptr s, std::vector<put_or_delete_item>&& b) :
+        schema(std::move(s)), _mutation_builders(std::move(b)) { }
     virtual ~put_or_delete_item_cas_request() = default;
     virtual std::optional<mutation> apply(foreign_ptr<lw_shared_ptr<query::result>> qr, const query::partition_slice& slice, api::timestamp_type ts, cdc::per_request_options& cdc_opts) override {
         std::optional<mutation> ret;
@@ -3055,48 +3049,17 @@ public:
     }
 };
 
-future<> executor::cas_write(schema_ptr schema, service::cas_shard cas_shard, const dht::decorated_key& dk,
-        const std::vector<put_or_delete_item>& mutation_builders, service::client_state& client_state,
-        tracing::trace_state_ptr trace_state, service_permit permit)
-{
-    if (!cas_shard.this_shard()) {
-        _stats.shard_bounce_for_lwt++;
-        return container().invoke_on(cas_shard.shard(), _ssg,
-                    [cs = client_state.move_to_other_shard(),
-                    &mb = mutation_builders,
-                    &dk,
-                    ks = schema->ks_name(),
-                    cf = schema->cf_name(),
-                    gt = tracing::global_trace_state_ptr(trace_state),
-                    permit = std::move(permit)]
-                    (executor& self) mutable {
-            return do_with(cs.get(), [&mb, &dk, ks = std::move(ks), cf = std::move(cf),
-                                    trace_state = tracing::trace_state_ptr(gt), &self]
-                                    (service::client_state& client_state) mutable {
-                auto schema = self._proxy.data_dictionary().find_schema(ks, cf);
-                service::cas_shard cas_shard(*schema, dk.token());
-
-                //FIXME: Instead of passing empty_service_permit() to the background operation,
-                // the current permit's lifetime should be prolonged, so that it's destructed
-                // only after all background operations are finished as well.
-                return self.cas_write(schema, std::move(cas_shard), dk, mb, client_state, std::move(trace_state), empty_service_permit());
-            });
-        });
-    }
-
+static future<> cas_write(service::storage_proxy& proxy, schema_ptr schema, service::cas_shard cas_shard, dht::decorated_key dk, std::vector<put_or_delete_item>&& mutation_builders,
+        service::client_state& client_state, tracing::trace_state_ptr trace_state, service_permit permit) {
     auto timeout = executor::default_timeout();
-    auto op = std::make_unique<put_or_delete_item_cas_request>(schema, mutation_builders);
-    auto* op_ptr = op.get();
+    auto op = seastar::make_shared<put_or_delete_item_cas_request>(schema, std::move(mutation_builders));
     auto cdc_opts = cdc::per_request_options{
-        .alternator = true,
-        .alternator_streams_increased_compatibility =
-                schema->cdc_options().enabled() && _proxy.data_dictionary().get_config().alternator_streams_increased_compatibility(),
     };
-    return _proxy.cas(schema, std::move(cas_shard), *op_ptr, nullptr, to_partition_ranges(dk),
+    return proxy.cas(schema, std::move(cas_shard), op, nullptr, to_partition_ranges(dk),
             {timeout, std::move(permit), client_state, trace_state},
             db::consistency_level::LOCAL_SERIAL, db::consistency_level::LOCAL_QUORUM,
-            timeout, timeout, true, std::move(cdc_opts)).finally([op = std::move(op)]{}).discard_result();
-    // We discarded cas()'s future value ("is_applied") because BatchWriteItem
+            timeout, timeout, true, std::move(cdc_opts)).discard_result();
+    // We discarded cas()'s future value ("is_applied") because BatchWriteItems
     // does not need to support conditional updates.
 }
 
@@ -3118,11 +3081,13 @@ struct schema_decorated_key_equal {
 
 // FIXME: if we failed writing some of the mutations, need to return a list
 // of these failed mutations rather than fail the whole write (issue #5650).
-future<> executor::do_batch_write(
+static future<> do_batch_write(service::storage_proxy& proxy,
+        smp_service_group ssg,
         std::vector<std::pair<schema_ptr, put_or_delete_item>> mutation_builders,
         service::client_state& client_state,
         tracing::trace_state_ptr trace_state,
-        service_permit permit) {
+        service_permit permit,
+        stats& stats) {
     if (mutation_builders.empty()) {
         return make_ready_future<>();
     }
@@ -3139,62 +3104,64 @@ future<> executor::do_batch_write(
         utils::chunked_vector<mutation> mutations;
         mutations.reserve(mutation_builders.size());
         api::timestamp_type now = api::new_timestamp();
-        bool any_cdc_enabled = false;
         for (auto& b : mutation_builders) {
             mutations.push_back(b.second.build(b.first, now));
-            any_cdc_enabled |= b.first->cdc_options().enabled();
         }
-        return _proxy.mutate(std::move(mutations),
+        return proxy.mutate(std::move(mutations),
                 db::consistency_level::LOCAL_QUORUM,
                 executor::default_timeout(),
                 trace_state,
                 std::move(permit),
                 db::allow_per_partition_rate_limit::yes,
                 false,
-                cdc::per_request_options{
-                    .alternator = true,
-                    .alternator_streams_increased_compatibility = any_cdc_enabled && _proxy.data_dictionary().get_config().alternator_streams_increased_compatibility(),
-                });
+                cdc::per_request_options{});
     } else {
         // Do the write via LWT:
         // Multiple mutations may be destined for the same partition, adding
         // or deleting different items of one partition. Join them together
         // because we can do them in one cas() call.
-        using map_type = std::unordered_map<schema_decorated_key, 
-            std::vector<put_or_delete_item>, 
-            schema_decorated_key_hash, 
-            schema_decorated_key_equal>;
-        auto key_builders = std::make_unique<map_type>(1, schema_decorated_key_hash{}, schema_decorated_key_equal{});
-        for (auto&& b : std::move(mutation_builders)) {
-            auto [it, added] = key_builders->try_emplace(schema_decorated_key {
-                .schema = b.first,
-                .dk = dht::decorate_key(*b.first, b.second.pk())
-            });
+        std::unordered_map<schema_decorated_key, std::vector<put_or_delete_item>, schema_decorated_key_hash, schema_decorated_key_equal>
+            key_builders(1, schema_decorated_key_hash{}, schema_decorated_key_equal{});
+        for (auto& b : mutation_builders) {
+            auto dk = dht::decorate_key(*b.first, b.second.pk());
+            auto [it, added] = key_builders.try_emplace(schema_decorated_key{b.first, dk});
             it->second.push_back(std::move(b.second));
         }
-        auto* key_builders_ptr = key_builders.get();
-        return parallel_for_each(*key_builders_ptr, [this, &client_state, trace_state, permit = std::move(permit)] (const auto& e) {
-            _stats.write_using_lwt++;
+        return parallel_for_each(std::move(key_builders), [&proxy, &client_state, &stats, trace_state, ssg, permit = std::move(permit)] (auto& e) {
+            stats.write_using_lwt++;
             auto desired_shard = service::cas_shard(*e.first.schema, e.first.dk.token());
-            auto s = e.first.schema;
+            if (desired_shard.this_shard()) {
+                return cas_write(proxy, e.first.schema, std::move(desired_shard), e.first.dk, std::move(e.second), client_state, trace_state, permit);
+            } else {
+                stats.shard_bounce_for_lwt++;
+                return proxy.container().invoke_on(desired_shard.shard(), ssg,
+                            [cs = client_state.move_to_other_shard(),
+                             mb = e.second,
+                             dk = e.first.dk,
+                             ks = e.first.schema->ks_name(),
+                             cf = e.first.schema->cf_name(),
+                             gt =  tracing::global_trace_state_ptr(trace_state),
+                             permit = std::move(permit)]
+                            (service::storage_proxy& proxy) mutable {
+                    return do_with(cs.get(), [&proxy, mb = std::move(mb), dk = std::move(dk), ks = std::move(ks), cf = std::move(cf),
+                                              trace_state = tracing::trace_state_ptr(gt)]
+                                              (service::client_state& client_state) mutable {
+                        auto schema = proxy.data_dictionary().find_schema(ks, cf);
 
-            static const auto* injection_name = "alternator_executor_batch_write_wait";
-            return utils::get_local_injector().inject(injection_name, [s = std::move(s)] (auto& handler) -> future<> {
-                const auto ks = handler.get("keyspace");
-                const auto cf = handler.get("table");
-                const auto shard = std::atoll(handler.get("shard")->data());
-                if (ks == s->ks_name() && cf == s->cf_name() && shard == this_shard_id()) {
-                    elogger.info("{}: hit", injection_name);
-                    co_await handler.wait_for_message(std::chrono::steady_clock::now() + std::chrono::minutes{5});
-                    elogger.info("{}: continue", injection_name);
-                }
-            }).then([&e, desired_shard = std::move(desired_shard),
-                 &client_state, trace_state = std::move(trace_state), permit = std::move(permit), this]() mutable
-            {
-                return cas_write(e.first.schema, std::move(desired_shard), e.first.dk,
-                    std::move(e.second), client_state, std::move(trace_state), std::move(permit));
-            });
-        }).finally([key_builders = std::move(key_builders)]{});
+                        // The desired_shard on the original shard remains alive for the duration
+                        // of cas_write on this shard and prevents any tablet operations.
+                        // However, we need a local instance of cas_shard on this shard
+                        // to pass it to sp::cas, so we just create a new one.
+                        service::cas_shard cas_shard(*schema, dk.token());
+
+                        //FIXME: Instead of passing empty_service_permit() to the background operation,
+                        // the current permit's lifetime should be prolonged, so that it's destructed
+                        // only after all background operations are finished as well.
+                        return cas_write(proxy, schema, std::move(cas_shard), dk, std::move(mb), client_state, std::move(trace_state), empty_service_permit());
+                    });
+                }).finally([desired_shard = std::move(desired_shard)]{});
+            }
+        });
     }
 }
 
@@ -3237,7 +3204,7 @@ future<executor::request_return_type> executor::batch_write_item(client_state& c
         per_table_stats->api_operations.batch_write_item++;
         per_table_stats->api_operations.batch_write_item_batch_total += it->value.Size();
         per_table_stats->api_operations.batch_write_item_histogram.add(it->value.Size());
-        tracing::add_alternator_table_name(trace_state, schema->cf_name());
+        tracing::add_table_name(trace_state, schema->ks_name(), schema->cf_name());
 
         std::unordered_set<primary_key, primary_key_hash, primary_key_equal> used_keys(
                 1, primary_key_hash{schema}, primary_key_equal{schema});
@@ -3341,7 +3308,7 @@ future<executor::request_return_type> executor::batch_write_item(client_state& c
     _stats.wcu_total[stats::DELETE_ITEM] += wcu_delete_units;
     _stats.api_operations.batch_write_item_batch_total += total_items;
     _stats.api_operations.batch_write_item_histogram.add(total_items);
-    co_await do_batch_write(std::move(mutation_builders), client_state, trace_state, std::move(permit));
+    co_await do_batch_write(_proxy, _ssg, std::move(mutation_builders), client_state, trace_state, std::move(permit), _stats);
     // FIXME: Issue #5650: If we failed writing some of the updates,
     // need to return a list of these failed updates in UnprocessedItems
     // rather than fail the whole write (issue #5650).
@@ -3386,7 +3353,7 @@ static bool hierarchy_filter(rjson::value& val, const attribute_path_map_node<T>
         }
         rjson::value newv = rjson::empty_object();
         for (auto it = v.MemberBegin(); it != v.MemberEnd(); ++it) {
-            std::string attr = rjson::to_string(it->name);
+            std::string attr = it->name.GetString();
             auto x = members.find(attr);
             if (x != members.end()) {
                 if (x->second) {
@@ -3606,7 +3573,7 @@ static std::optional<attrs_to_get> calculate_attrs_to_get(const rjson::value& re
         const rjson::value& attributes_to_get = req["AttributesToGet"];
         attrs_to_get ret;
         for (auto it = attributes_to_get.Begin(); it != attributes_to_get.End(); ++it) {
-            attribute_path_map_add("AttributesToGet", ret, rjson::to_string(*it));
+            attribute_path_map_add("AttributesToGet", ret, it->GetString());
             validate_attr_name_length("AttributesToGet", it->GetStringLength(), false);
         }
         if (ret.empty()) {
@@ -4272,12 +4239,12 @@ inline void update_item_operation::apply_attribute_updates(const std::unique_ptr
         attribute_collector& modified_attrs, bool& any_updates, bool& any_deletes) const {
     for (auto it = _attribute_updates->MemberBegin(); it != _attribute_updates->MemberEnd(); ++it) {
         // Note that it.key() is the name of the column, *it is the operation
-        bytes column_name = to_bytes(rjson::to_string_view(it->name));
+        bytes column_name = to_bytes(it->name.GetString());
         const column_definition* cdef = _schema->get_column_definition(column_name);
         if (cdef && cdef->is_primary_key()) {
-            throw api_error::validation(format("UpdateItem cannot update key column {}", rjson::to_string_view(it->name)));
+            throw api_error::validation(format("UpdateItem cannot update key column {}", it->name.GetString()));
         }
-        std::string action = rjson::to_string((it->value)["Action"]);
+        std::string action = (it->value)["Action"].GetString();
         if (action == "DELETE") {
             // The DELETE operation can do two unrelated tasks. Without a
             // "Value" option, it is used to delete an attribute. With a
@@ -4497,7 +4464,7 @@ future<executor::request_return_type> executor::update_item(client_state& client
     elogger.trace("update_item {}", request);
 
     auto op = make_shared<update_item_operation>(*_parsed_expression_cache, _proxy, std::move(request));
-    tracing::add_alternator_table_name(trace_state, op->schema()->cf_name());
+    tracing::add_table_name(trace_state, op->schema()->ks_name(), op->schema()->cf_name());
     const bool needs_read_before_write = _proxy.data_dictionary().get_config().alternator_force_read_before_write() || op->needs_read_before_write();
 
     co_await verify_permission(_enforce_authorization, _warn_authorization, client_state, op->schema(), auth::permission::MODIFY, _stats);
@@ -4578,7 +4545,7 @@ future<executor::request_return_type> executor::get_item(client_state& client_st
     schema_ptr schema = get_table(_proxy, request);
     lw_shared_ptr<stats> per_table_stats = get_stats_from_schema(_proxy, *schema);
     per_table_stats->api_operations.get_item++;
-    tracing::add_alternator_table_name(trace_state, schema->cf_name());
+    tracing::add_table_name(trace_state, schema->ks_name(), schema->cf_name());
 
     rjson::value& query_key = request["Key"];
     db::consistency_level cl = get_read_consistency(request);
@@ -4727,7 +4694,7 @@ future<executor::request_return_type> executor::batch_get_item(client_state& cli
     uint batch_size = 0;
     for (auto it = request_items.MemberBegin(); it != request_items.MemberEnd(); ++it) {
         table_requests rs(get_table_from_batch_request(_proxy, it));
-        tracing::add_alternator_table_name(trace_state, rs.schema->cf_name());
+        tracing::add_table_name(trace_state, sstring(executor::KEYSPACE_NAME_PREFIX) + rs.schema->cf_name(), rs.schema->cf_name());
         rs.cl = get_read_consistency(it->value);
         std::unordered_set<std::string> used_attribute_names;
         rs.attrs_to_get = ::make_shared<const std::optional<attrs_to_get>>(calculate_attrs_to_get(it->value, *_parsed_expression_cache, used_attribute_names));
@@ -5163,15 +5130,13 @@ static rjson::value encode_paging_state(const schema& schema, const service::pag
     }
     auto pos = paging_state.get_position_in_partition();
     if (pos.has_key()) {
-        // Alternator itself allows at most one column in clustering key, but 
-        // user can use Alternator api to access system tables which might have
-        // multiple clustering key columns. So we need to handle that case here.
-        auto cdef_it = schema.clustering_key_columns().begin();        
-        for(const auto &exploded_ck : pos.key().explode()) {
-            rjson::add_with_string_name(last_evaluated_key, std::string_view(cdef_it->name_as_text()), rjson::empty_object());
-            rjson::value& key_entry = last_evaluated_key[cdef_it->name_as_text()];
-            rjson::add_with_string_name(key_entry, type_to_string(cdef_it->type), json_key_column_value(exploded_ck, *cdef_it));
-            ++cdef_it;
+        auto exploded_ck = pos.key().explode();
+        auto exploded_ck_it = exploded_ck.begin();
+        for (const column_definition& cdef : schema.clustering_key_columns()) {
+            rjson::add_with_string_name(last_evaluated_key, std::string_view(cdef.name_as_text()), rjson::empty_object());
+            rjson::value& key_entry = last_evaluated_key[cdef.name_as_text()];
+            rjson::add_with_string_name(key_entry, type_to_string(cdef.type), json_key_column_value(*exploded_ck_it, cdef));
+            ++exploded_ck_it;
         }
     }
     // To avoid possible conflicts (and thus having to reserve these names) we
@@ -5331,7 +5296,6 @@ future<executor::request_return_type> executor::scan(client_state& client_state,
     elogger.trace("Scanning {}", request);
 
     auto [schema, table_type] = get_table_or_view(_proxy, request);
-    tracing::add_alternator_table_name(trace_state, schema->cf_name());
     get_stats_from_schema(_proxy, *schema)->api_operations.scan++;
     auto segment = get_int_attribute(request, "Segment");
     auto total_segments = get_int_attribute(request, "TotalSegments");
@@ -5474,7 +5438,7 @@ calculate_bounds_conditions(schema_ptr schema, const rjson::value& conditions) {
     std::vector<query::clustering_range> ck_bounds;
 
     for (auto it = conditions.MemberBegin(); it != conditions.MemberEnd(); ++it) {
-        sstring key = rjson::to_sstring(it->name);
+        std::string key = it->name.GetString();
         const rjson::value& condition = it->value;
 
         const rjson::value& comp_definition = rjson::get(condition, "ComparisonOperator");
@@ -5482,13 +5446,13 @@ calculate_bounds_conditions(schema_ptr schema, const rjson::value& conditions) {
 
         const column_definition& pk_cdef = schema->partition_key_columns().front();
         const column_definition* ck_cdef = schema->clustering_key_size() > 0 ? &schema->clustering_key_columns().front() : nullptr;
-        if (key == pk_cdef.name_as_text()) {
+        if (sstring(key) == pk_cdef.name_as_text()) {
             if (!partition_ranges.empty()) {
                 throw api_error::validation("Currently only a single restriction per key is allowed");
             }
             partition_ranges.push_back(calculate_pk_bound(schema, pk_cdef, comp_definition, attr_list));
         }
-        if (ck_cdef && key == ck_cdef->name_as_text()) {
+        if (ck_cdef && sstring(key) == ck_cdef->name_as_text()) {
             if (!ck_bounds.empty()) {
                 throw api_error::validation("Currently only a single restriction per key is allowed");
             }
@@ -5811,7 +5775,7 @@ future<executor::request_return_type> executor::query(client_state& client_state
 
     auto [schema, table_type] = get_table_or_view(_proxy, request);
     get_stats_from_schema(_proxy, *schema)->api_operations.query++;
-    tracing::add_alternator_table_name(trace_state, schema->cf_name());
+    tracing::add_table_name(trace_state, schema->ks_name(), schema->cf_name());
 
     rjson::value* exclusive_start_key = rjson::find(request, "ExclusiveStartKey");
     db::consistency_level cl = get_read_consistency(request);
@@ -5889,7 +5853,7 @@ future<executor::request_return_type> executor::list_tables(client_state& client
 
     rjson::value* exclusive_start_json = rjson::find(request, "ExclusiveStartTableName");
     rjson::value* limit_json = rjson::find(request, "Limit");
-    std::string exclusive_start = exclusive_start_json ? rjson::to_string(*exclusive_start_json) : "";
+    std::string exclusive_start = exclusive_start_json ? exclusive_start_json->GetString() : "";
     int limit = limit_json ? limit_json->GetInt() : 100;
     if (limit < 1 || limit > 100) {
         co_return api_error::validation("Limit must be greater than 0 and no greater than 100");

alternator/executor.hh

@@ -40,7 +40,6 @@ namespace cql3::selection {
 
 namespace service {
     class storage_proxy;
-    class cas_shard;
 }
 
 namespace cdc {
@@ -58,7 +57,6 @@ class schema_builder;
 namespace alternator {
 
 class rmw_operation;
-class put_or_delete_item;
 
 schema_ptr get_table(service::storage_proxy& proxy, const rjson::value& request);
 bool is_alternator_keyspace(const sstring& ks_name);
@@ -221,16 +219,6 @@ private:
 
     static void describe_key_schema(rjson::value& parent, const schema&, std::unordered_map<std::string,std::string> * = nullptr, const std::map<sstring, sstring> *tags = nullptr);
 
-    future<> do_batch_write(
-        std::vector<std::pair<schema_ptr, put_or_delete_item>> mutation_builders,
-        service::client_state& client_state,
-        tracing::trace_state_ptr trace_state,
-        service_permit permit);
-
-    future<> cas_write(schema_ptr schema, service::cas_shard cas_shard, const dht::decorated_key& dk,
-        const std::vector<put_or_delete_item>& mutation_builders, service::client_state& client_state,
-        tracing::trace_state_ptr trace_state, service_permit permit);
-
 public:
     static void describe_key_schema(rjson::value& parent, const schema& schema, std::unordered_map<std::string,std::string>&, const std::map<sstring, sstring> *tags = nullptr);
 

alternator/serialization.cc

@@ -282,23 +282,15 @@ std::string type_to_string(data_type type) {
     return it->second;
 }
 
-std::optional<bytes> try_get_key_column_value(const rjson::value& item, const column_definition& column) {
+bytes get_key_column_value(const rjson::value& item, const column_definition& column) {
     std::string column_name = column.name_as_text();
     const rjson::value* key_typed_value = rjson::find(item, column_name);
     if (!key_typed_value) {
-        return std::nullopt;
+        throw api_error::validation(fmt::format("Key column {} not found", column_name));
     }
     return get_key_from_typed_value(*key_typed_value, column);
 }
 
-bytes get_key_column_value(const rjson::value& item, const column_definition& column) {
-    auto value = try_get_key_column_value(item, column);
-    if (!value) {
-        throw api_error::validation(fmt::format("Key column {} not found", column.name_as_text()));
-    }
-    return std::move(*value);
-}
-
 // Parses the JSON encoding for a key value, which is a map with a single
 // entry whose key is the type and the value is the encoded value.
 // If this type does not match the desired "type_str", an api_error::validation
@@ -388,38 +380,20 @@ clustering_key ck_from_json(const rjson::value& item, schema_ptr schema) {
         return clustering_key::make_empty();
     }
     std::vector<bytes> raw_ck;
-    // Note: it's possible to get more than one clustering column here, as
-    // Alternator can be used to read scylla internal tables.
+    // FIXME: this is a loop, but we really allow only one clustering key column.
     for (const column_definition& cdef : schema->clustering_key_columns()) {
-        auto raw_value = get_key_column_value(item,  cdef);
+        bytes raw_value = get_key_column_value(item,  cdef);
         raw_ck.push_back(std::move(raw_value));
     }
 
     return clustering_key::from_exploded(raw_ck);
 }
 
-clustering_key_prefix ck_prefix_from_json(const rjson::value& item, schema_ptr schema) {
-    if (schema->clustering_key_size() == 0) {
-        return clustering_key_prefix::make_empty();
-    }
-    std::vector<bytes> raw_ck;
-    for (const column_definition& cdef : schema->clustering_key_columns()) {
-        auto raw_value = try_get_key_column_value(item,  cdef);
-        if (!raw_value) {
-            break;
-        }
-        raw_ck.push_back(std::move(*raw_value));
-    }
-
-    return clustering_key_prefix::from_exploded(raw_ck);
-}
-
 position_in_partition pos_from_json(const rjson::value& item, schema_ptr schema) {
-    const bool is_alternator_ks = is_alternator_keyspace(schema->ks_name());
-    if (is_alternator_ks) {
-        return position_in_partition::for_key(ck_from_json(item, schema));
+    auto ck = ck_from_json(item, schema);
+    if (is_alternator_keyspace(schema->ks_name())) {
+        return position_in_partition::for_key(std::move(ck));
     }
-    
     const auto region_item = rjson::find(item, scylla_paging_region);
     const auto weight_item = rjson::find(item, scylla_paging_weight);
     if (bool(region_item) != bool(weight_item)) {
@@ -439,9 +413,8 @@ position_in_partition pos_from_json(const rjson::value& item, schema_ptr schema)
         } else {
             throw std::runtime_error(fmt::format("Invalid value for weight: {}", weight_view));
         }
-        return position_in_partition(region, weight, region == partition_region::clustered ? std::optional(ck_prefix_from_json(item, schema)) : std::nullopt);
+        return position_in_partition(region, weight, region == partition_region::clustered ? std::optional(std::move(ck)) : std::nullopt);
     }
-    auto ck = ck_from_json(item, schema);
     if (ck.is_empty()) {
         return position_in_partition::for_partition_start();
     }
@@ -496,7 +469,7 @@ const std::pair<std::string, const rjson::value*> unwrap_set(const rjson::value&
         return {"", nullptr};
     }
     auto it = v.MemberBegin();
-    const std::string it_key = rjson::to_string(it->name);
+    const std::string it_key = it->name.GetString();
     if (it_key != "SS" && it_key != "BS" && it_key != "NS") {
         return {std::move(it_key), nullptr};
     }

alternator/server.cc

@@ -13,7 +13,6 @@
 #include <seastar/http/function_handlers.hh>
 #include <seastar/http/short_streams.hh>
 #include <seastar/core/coroutine.hh>
-#include <seastar/coroutine/maybe_yield.hh>
 #include <seastar/util/defer.hh>
 #include <seastar/util/short_streams.hh>
 #include "seastarx.hh"
@@ -33,7 +32,6 @@
 #include "utils/aws_sigv4.hh"
 #include "client_data.hh"
 #include "utils/updateable_value.hh"
-#include <zlib.h>
 
 static logging::logger slogger("alternator-server");
 
@@ -553,106 +551,6 @@ read_entire_stream(input_stream<char>& inp, size_t length_limit) {
     co_return ret;
 }
 
-// safe_gzip_stream is an exception-safe wrapper for zlib's z_stream.
-// The "z_stream" struct is used by zlib to hold state while decompressing a
-// stream of data. It allocates memory which must be freed with inflateEnd(),
-// which the destructor of this class does.
-class safe_gzip_zstream {
-    z_stream _zs;
-public:
-    safe_gzip_zstream() {
-        memset(&_zs, 0, sizeof(_zs));
-        // The strange 16 + WMAX_BITS tells zlib to expect and decode
-        // a gzip header, not a zlib header.
-        if (inflateInit2(&_zs, 16 + MAX_WBITS) != Z_OK) {
-            // Should only happen if memory allocation fails
-            throw std::bad_alloc();
-        }
-    }
-    ~safe_gzip_zstream() {
-        inflateEnd(&_zs);
-    }
-    z_stream* operator->() {
-        return &_zs;
-    }
-    z_stream* get() {
-        return &_zs;
-    }
-    void reset() {
-        inflateReset(&_zs);
-    }
-};
-
-// ungzip() takes a chunked_content with a gzip-compressed request body,
-// uncompresses it, and returns the uncompressed content as a chunked_content.
-// If the uncompressed content exceeds length_limit, an error is thrown.
-static future<chunked_content>
-ungzip(chunked_content&& compressed_body, size_t length_limit) {
-    chunked_content ret;
-    // output_buf can be any size - when uncompressing input_buf, it doesn't
-    // need to fit in a single output_buf, we'll use multiple output_buf for
-    // a single input_buf if needed.
-    constexpr size_t OUTPUT_BUF_SIZE = 4096;
-    temporary_buffer<char> output_buf;
-    safe_gzip_zstream strm;
-    bool complete_stream = false; // empty input is not a valid gzip
-    size_t total_out_bytes = 0;
-    for (const temporary_buffer<char>& input_buf : compressed_body) {
-        if (input_buf.empty()) {
-            continue;
-        }
-        complete_stream = false;
-        strm->next_in = (Bytef*) input_buf.get();
-        strm->avail_in = (uInt) input_buf.size();
-        do {
-            co_await coroutine::maybe_yield();
-            if (output_buf.empty()) {
-                output_buf = temporary_buffer<char>(OUTPUT_BUF_SIZE);
-            }
-            strm->next_out = (Bytef*) output_buf.get();
-            strm->avail_out = OUTPUT_BUF_SIZE;
-            int e = inflate(strm.get(), Z_NO_FLUSH);
-            size_t out_bytes = OUTPUT_BUF_SIZE - strm->avail_out;
-            if (out_bytes > 0) {
-                // If output_buf is nearly full, we save it as-is in ret. But
-                // if it only has little data, better copy to a small buffer.
-                if (out_bytes > OUTPUT_BUF_SIZE/2) {
-                    ret.push_back(std::move(output_buf).prefix(out_bytes));
-                    // output_buf is now empty. if this loop finds more input,
-                    // we'll allocate a new output buffer.
-                } else {
-                    ret.push_back(temporary_buffer<char>(output_buf.get(), out_bytes));
-                }
-                total_out_bytes += out_bytes;
-                if (total_out_bytes > length_limit) {
-                    throw api_error::payload_too_large(fmt::format("Request content length limit of {} bytes exceeded", length_limit));
-                }
-            }
-            if (e == Z_STREAM_END) {
-                // There may be more input after the first gzip stream - in
-                // either this input_buf or the next one. The additional input
-                // should be a second concatenated gzip. We need to allow that
-                // by resetting the gzip stream and continuing the input loop
-                // until there's no more input.
-                strm.reset();
-                if (strm->avail_in == 0) {
-                    complete_stream = true;
-                    break;
-                }
-            } else if (e != Z_OK && e != Z_BUF_ERROR) {
-                // DynamoDB returns an InternalServerError when given a bad
-                // gzip request body. See test test_broken_gzip_content
-                throw api_error::internal("Error during gzip decompression of request body");
-            }
-        } while (strm->avail_in > 0 || strm->avail_out == 0);
-    }
-    if (!complete_stream) {
-        // The gzip stream was not properly finished with Z_STREAM_END
-        throw api_error::internal("Truncated gzip in request body");
-    }
-    co_return ret;
-}
-
 future<executor::request_return_type> server::handle_api_request(std::unique_ptr<request> req) {
     _executor._stats.total_operations++;
     sstring target = req->get_header("X-Amz-Target");
@@ -690,21 +588,6 @@ future<executor::request_return_type> server::handle_api_request(std::unique_ptr
         units.return_units(mem_estimate - new_mem_estimate);
     }
     auto username = co_await verify_signature(*req, content);
-    // If the request is compressed, uncompress it now, after we checked
-    // the signature (the signature is computed on the compressed content).
-    // We apply the request_content_length_limit again to the uncompressed
-    // content - we don't want to allow a tiny compressed request to
-    // expand to a huge uncompressed request.
-    sstring content_encoding = req->get_header("Content-Encoding");
-    if (content_encoding == "gzip") {
-        content = co_await ungzip(std::move(content), request_content_length_limit);
-    } else if (!content_encoding.empty()) {
-        // DynamoDB returns a 500 error for unsupported Content-Encoding.
-        // I'm not sure if this is the best error code, but let's do it too.
-        // See the test test_garbage_content_encoding confirming this case.
-        co_return api_error::internal("Unsupported Content-Encoding");
-    }
-
     // As long as the system_clients_entry object is alive, this request will
     // be visible in the "system.clients" virtual table. When requested, this
     // entry will be formatted by server::ongoing_request::make_client_data().

alternator/ttl.cc

@@ -93,7 +93,7 @@ future<executor::request_return_type> executor::update_time_to_live(client_state
     if (v->GetStringLength() < 1 || v->GetStringLength() > 255) {
         co_return api_error::validation("The length of AttributeName must be between 1 and 255");
     }
-    sstring attribute_name = rjson::to_sstring(*v);
+    sstring attribute_name(v->GetString(), v->GetStringLength());
 
     co_await verify_permission(_enforce_authorization, _warn_authorization, client_state, schema, auth::permission::ALTER, _stats);
     co_await db::modify_tags(_mm, schema->ks_name(), schema->cf_name(), [&](std::map<sstring, sstring>& tags_map) {

api/CMakeLists.txt

@@ -106,8 +106,5 @@ target_link_libraries(api
     wasmtime_bindings
     absl::headers)
 
-if (Scylla_USE_PRECOMPILED_HEADER_USE)
-  target_precompile_headers(api REUSE_FROM scylla-precompiled-header)
-endif()
 check_headers(check-headers api
   GLOB_RECURSE ${CMAKE_CURRENT_SOURCE_DIR}/*.hh)

api/api-doc/storage_service.json

@@ -3051,7 +3051,7 @@
                   },
                   {
                      "name":"incremental_mode",
-                     "description":"Set the incremental repair mode. Can be 'disabled', 'incremental', or 'full'. 'incremental': The incremental repair logic is enabled. Unrepaired sstables will be included for repair. Repaired sstables will be skipped. The incremental repair states will be updated after repair. 'full': The incremental repair logic is enabled. Both repaired and unrepaired sstables will be included for repair. The incremental repair states will be updated after repair. 'disabled': The incremental repair logic is disabled completely. The incremental repair states, e.g., repaired_at in sstables and sstables_repaired_at in the system.tablets table, will not be updated after repair. When the option is not provided, it defaults to 'disabled' mode.",
+                     "description":"Set the incremental repair mode. Can be 'disabled', 'incremental', or 'full'. 'incremental': The incremental repair logic is enabled. Unrepaired sstables will be included for repair. Repaired sstables will be skipped. The incremental repair states will be updated after repair. 'full': The incremental repair logic is enabled. Both repaired and unrepaired sstables will be included for repair. The incremental repair states will be updated after repair. 'disabled': The incremental repair logic is disabled completely. The incremental repair states, e.g., repaired_at in sstables and sstables_repaired_at in the system.tablets table, will not be updated after repair. When the option is not provided, it defaults to incremental mode.",
                      "required":false,
                      "allowMultiple":false,
                      "type":"string",

api/column_family.cc

@@ -66,13 +66,6 @@ static future<json::json_return_type>  get_cf_stats(sharded<replica::database>&
     }, std::plus<int64_t>());
 }
 
-static future<json::json_return_type>  get_cf_stats(sharded<replica::database>& db,
-        std::function<int64_t(const replica::column_family_stats&)> f) {
-    return map_reduce_cf(db, int64_t(0), [f](const replica::column_family& cf) {
-        return f(cf.get_stats());
-    }, std::plus<int64_t>());
-}
-
 static future<json::json_return_type> for_tables_on_all_shards(sharded<replica::database>& db, std::vector<table_info> tables, std::function<future<>(replica::table&)> set) {
     return do_with(std::move(tables), [&db, set] (const std::vector<table_info>& tables) {
         return db.invoke_on_all([&tables, set] (replica::database& db) {
@@ -1073,14 +1066,10 @@ void set_column_family(http_context& ctx, routes& r, sharded<replica::database>&
     });
 
     ss::get_load.set(r, [&db] (std::unique_ptr<http::request> req) {
-        return get_cf_stats(db, [](const replica::column_family_stats& stats) {
-            return stats.live_disk_space_used.on_disk;
-        });
+        return get_cf_stats(db, &replica::column_family_stats::live_disk_space_used);
     });
     ss::get_metrics_load.set(r, [&db] (std::unique_ptr<http::request> req) {
-        return get_cf_stats(db, [](const replica::column_family_stats& stats) {
-            return stats.live_disk_space_used.on_disk;
-        });
+        return get_cf_stats(db, &replica::column_family_stats::live_disk_space_used);
     });
 
     ss::get_keyspaces.set(r, [&db] (const_req req) {

audit/CMakeLists.txt

@@ -17,7 +17,4 @@ target_link_libraries(scylla_audit
   PRIVATE
     cql3)
 
-if (Scylla_USE_PRECOMPILED_HEADER_USE)
-  target_precompile_headers(scylla_audit REUSE_FROM scylla-precompiled-header)
-endif()
 add_whole_archive(audit scylla_audit)

auth/CMakeLists.txt

@@ -9,7 +9,6 @@ target_sources(scylla_auth
     allow_all_authorizer.cc
     authenticated_user.cc
     authenticator.cc
-    cache.cc
     certificate_authenticator.cc
     common.cc
     default_authorizer.cc
@@ -45,8 +44,5 @@ target_link_libraries(scylla_auth
 
 add_whole_archive(auth scylla_auth)
 
-if (Scylla_USE_PRECOMPILED_HEADER_USE)
-  target_precompile_headers(scylla_auth REUSE_FROM scylla-precompiled-header)
-endif()
 check_headers(check-headers scylla_auth
   GLOB_RECURSE ${CMAKE_CURRENT_SOURCE_DIR}/*.hh)

auth/allow_all_authenticator.cc

@@ -23,7 +23,6 @@ static const class_registrator<
         cql3::query_processor&,
         ::service::raft_group0_client&,
         ::service::migration_manager&,
-        cache&,
         utils::alien_worker&> registration("org.apache.cassandra.auth.AllowAllAuthenticator");
 
 }

auth/allow_all_authenticator.hh

@@ -12,7 +12,6 @@
 
 #include "auth/authenticated_user.hh"
 #include "auth/authenticator.hh"
-#include "auth/cache.hh"
 #include "auth/common.hh"
 #include "utils/alien_worker.hh"
 
@@ -30,7 +29,7 @@ extern const std::string_view allow_all_authenticator_name;
 
 class allow_all_authenticator final : public authenticator {
 public:
-    allow_all_authenticator(cql3::query_processor&, ::service::raft_group0_client&, ::service::migration_manager&, cache&, utils::alien_worker&) {
+    allow_all_authenticator(cql3::query_processor&, ::service::raft_group0_client&, ::service::migration_manager&, utils::alien_worker&) {
     }
 
     virtual future<> start() override {

auth/cache.cc

@@ -1,180 +0,0 @@
-/*
- * Copyright (C) 2017-present ScyllaDB
- */
-
-/*
- * SPDX-License-Identifier: LicenseRef-ScyllaDB-Source-Available-1.0
- */
-
-#include "auth/cache.hh"
-#include "auth/common.hh"
-#include "auth/roles-metadata.hh"
-#include "cql3/query_processor.hh"
-#include "cql3/untyped_result_set.hh"
-#include "db/consistency_level_type.hh"
-#include "db/system_keyspace.hh"
-#include "schema/schema.hh"
-#include <iterator>
-#include <seastar/coroutine/maybe_yield.hh>
-#include <seastar/core/format.hh>
-
-namespace auth {
-
-logging::logger logger("auth-cache");
-
-cache::cache(cql3::query_processor& qp) noexcept
-    : _current_version(0)
-    , _qp(qp) {
-}
-
-lw_shared_ptr<const cache::role_record> cache::get(const role_name_t& role) const noexcept {
-    auto it = _roles.find(role);
-    if (it == _roles.end()) {
-        return {};
-    }
-    return it->second;
-}
-
-future<lw_shared_ptr<cache::role_record>> cache::fetch_role(const role_name_t& role) const {
-    auto rec = make_lw_shared<role_record>();
-    rec->version = _current_version;
-
-    auto fetch = [this, &role](const sstring& q) {
-        return _qp.execute_internal(q, db::consistency_level::LOCAL_ONE,
-                internal_distributed_query_state(), {role},
-                cql3::query_processor::cache_internal::yes);
-    };
-    // roles
-    {
-        static const sstring q = format("SELECT * FROM {}.{} WHERE role = ?", db::system_keyspace::NAME, meta::roles_table::name);
-        auto rs = co_await fetch(q);
-        if (!rs->empty()) {
-            auto& r = rs->one();
-            rec->is_superuser = r.get_or<bool>("is_superuser", false);
-            rec->can_login = r.get_or<bool>("can_login", false);
-            rec->salted_hash = r.get_or<sstring>("salted_hash", "");
-            if (r.has("member_of")) {
-                auto mo = r.get_set<sstring>("member_of");
-                rec->member_of.insert(
-                        std::make_move_iterator(mo.begin()),
-                        std::make_move_iterator(mo.end()));
-            }
-        } else {
-            // role got deleted
-            co_return nullptr;
-        }
-    }
-    // members
-    {
-        static const sstring q = format("SELECT role, member FROM {}.{} WHERE role = ?", db::system_keyspace::NAME, ROLE_MEMBERS_CF);
-        auto rs = co_await fetch(q);
-        for (const auto& r : *rs) {
-            rec->members.insert(r.get_as<sstring>("member"));
-            co_await coroutine::maybe_yield();
-        }
-    }
-    // attributes
-    {
-        static const sstring q = format("SELECT role, name, value FROM {}.{} WHERE role = ?", db::system_keyspace::NAME, ROLE_ATTRIBUTES_CF);
-        auto rs = co_await fetch(q);
-        for (const auto& r : *rs) {
-            rec->attributes[r.get_as<sstring>("name")] =
-                    r.get_as<sstring>("value");
-            co_await coroutine::maybe_yield();
-        }
-    }
-    // permissions
-    {
-        static const sstring q = format("SELECT role, resource, permissions FROM {}.{} WHERE role = ?", db::system_keyspace::NAME, PERMISSIONS_CF);
-        auto rs = co_await fetch(q);
-        for (const auto& r : *rs) {
-            auto resource = r.get_as<sstring>("resource");
-            auto perms_strings = r.get_set<sstring>("permissions");
-            std::unordered_set<sstring> perms_set(perms_strings.begin(), perms_strings.end());
-            auto pset = permissions::from_strings(perms_set);
-            rec->permissions[std::move(resource)] = std::move(pset);
-            co_await coroutine::maybe_yield();
-        }
-    }
-    co_return rec;
-}
-
-future<> cache::prune_all() noexcept {
-    for (auto it = _roles.begin(); it != _roles.end(); ) {
-        if (it->second->version != _current_version) {
-            _roles.erase(it++);
-            co_await coroutine::maybe_yield();
-        } else {
-            ++it;
-        }
-    }
-    co_return;
-}
-
-future<> cache::load_all() {
-    if (legacy_mode(_qp)) {
-        co_return;
-    }
-    SCYLLA_ASSERT(this_shard_id() == 0);
-    ++_current_version;
-
-    logger.info("Loading all roles");
-    const uint32_t page_size = 128;
-    auto loader = [this](const cql3::untyped_result_set::row& r) -> future<stop_iteration> {
-        const auto name = r.get_as<sstring>("role");
-        auto role = co_await fetch_role(name);
-        if (role) {
-            _roles[name] = role;
-        }
-        co_return stop_iteration::no;
-    };
-    co_await _qp.query_internal(format("SELECT * FROM {}.{}",
-            db::system_keyspace::NAME, meta::roles_table::name),
-            db::consistency_level::LOCAL_ONE, {}, page_size, loader);
-
-    co_await prune_all();
-    for (const auto& [name, role] : _roles) {
-        co_await distribute_role(name, role);
-    }
-    co_await container().invoke_on_others([this](cache& c) -> future<> {
-        c._current_version = _current_version;
-        co_await c.prune_all();
-    });
-}
-
-future<> cache::load_roles(std::unordered_set<role_name_t> roles) {
-    if (legacy_mode(_qp)) {
-        co_return;
-    }
-    for (const auto& name : roles) {
-        logger.info("Loading role {}", name);
-        auto role = co_await fetch_role(name);
-         if (role) {
-            _roles[name] = role;
-        } else {
-            _roles.erase(name);
-        }
-        co_await distribute_role(name, role);
-    }
-}
-
-future<> cache::distribute_role(const role_name_t& name, lw_shared_ptr<role_record> role) {
-    auto role_ptr = role.get();
-    co_await container().invoke_on_others([&name, role_ptr](cache& c) {
-        if (!role_ptr) {
-            c._roles.erase(name);
-            return;
-        }
-        auto role_copy = make_lw_shared<role_record>(*role_ptr);
-        c._roles[name] = std::move(role_copy);
-    });
-}
-
-bool cache::includes_table(const table_id& id) noexcept {
-    return id == db::system_keyspace::roles()->id()
-            || id == db::system_keyspace::role_members()->id()
-            || id == db::system_keyspace::role_attributes()->id()
-            || id == db::system_keyspace::role_permissions()->id();
-}
-
-} // namespace auth

auth/cache.hh

@@ -1,61 +0,0 @@
-/*
- * Copyright (C) 2025-present ScyllaDB
- */
-
-/*
- * SPDX-License-Identifier: LicenseRef-ScyllaDB-Source-Available-1.0
- */
-
-#pragma once
-
-#include <unordered_set>
-#include <unordered_map>
-
-#include <seastar/core/sstring.hh>
-#include <seastar/core/future.hh>
-#include <seastar/core/sharded.hh>
-#include <seastar/core/shared_ptr.hh>
-
-#include <absl/container/flat_hash_map.h>
-
-#include "auth/permission.hh"
-#include "auth/common.hh"
-
-namespace cql3 { class query_processor; }
-
-namespace auth {
-
-class cache : public peering_sharded_service<cache> {
-public:
-    using role_name_t = sstring;
-    using version_tag_t = char;
-
-	struct role_record {
-        bool can_login = false;
-        bool is_superuser = false;
-        std::unordered_set<role_name_t> member_of;
-        std::unordered_set<role_name_t> members;
-        sstring salted_hash;
-        std::unordered_map<sstring, sstring> attributes;
-        std::unordered_map<sstring, permission_set> permissions;
-        version_tag_t version; // used for seamless cache reloads
-    };
-
-    explicit cache(cql3::query_processor& qp) noexcept;
-    lw_shared_ptr<const role_record> get(const role_name_t& role) const noexcept;
-    future<> load_all();
-    future<> load_roles(std::unordered_set<role_name_t> roles);
-    static bool includes_table(const table_id&) noexcept;
-
-private:
-    using roles_map = absl::flat_hash_map<role_name_t, lw_shared_ptr<role_record>>;
-    roles_map _roles;
-    version_tag_t _current_version;
-    cql3::query_processor& _qp;
-
-    future<lw_shared_ptr<role_record>> fetch_role(const role_name_t& role) const;
-    future<> prune_all() noexcept;
-    future<> distribute_role(const role_name_t& name, const lw_shared_ptr<role_record> role);
-};
-
-} // namespace auth

auth/certificate_authenticator.cc

@@ -8,7 +8,6 @@
  */
 
 #include "auth/certificate_authenticator.hh"
-#include "auth/cache.hh"
 
 #include <boost/regex.hpp>
 #include <fmt/ranges.h>
@@ -35,14 +34,13 @@ static const class_registrator<auth::authenticator
     , cql3::query_processor&
     , ::service::raft_group0_client&
     , ::service::migration_manager&
-    , auth::cache&
     , utils::alien_worker&> cert_auth_reg(CERT_AUTH_NAME);
 
 enum class auth::certificate_authenticator::query_source {
     subject, altname
 };
 
-auth::certificate_authenticator::certificate_authenticator(cql3::query_processor& qp, ::service::raft_group0_client&, ::service::migration_manager&, auth::cache&, utils::alien_worker&)
+auth::certificate_authenticator::certificate_authenticator(cql3::query_processor& qp, ::service::raft_group0_client&, ::service::migration_manager&, utils::alien_worker&)
     : _queries([&] {
         auto& conf = qp.db().get_config();
         auto queries = conf.auth_certificate_role_queries();
@@ -77,9 +75,9 @@ auth::certificate_authenticator::certificate_authenticator(cql3::query_processor
                         throw std::invalid_argument(fmt::format("Invalid source: {}", map.at(cfg_source_attr)));
                     }
                     continue;
-                } catch (const std::out_of_range&) {
+                } catch (std::out_of_range&) {
                     // just fallthrough
-                } catch (const boost::regex_error&) {
+                } catch (boost::regex_error&) {
                     std::throw_with_nested(std::invalid_argument(fmt::format("Invalid query expression: {}", map.at(cfg_query_attr))));
                 }
             }

auth/certificate_authenticator.hh

@@ -26,15 +26,13 @@ class raft_group0_client;
 
 namespace auth {
 
-class cache;
-
 extern const std::string_view certificate_authenticator_name;
 
 class certificate_authenticator : public authenticator {
     enum class query_source;
     std::vector<std::pair<query_source, boost::regex>> _queries;
 public:
-    certificate_authenticator(cql3::query_processor&, ::service::raft_group0_client&, ::service::migration_manager&, cache&, utils::alien_worker&);
+    certificate_authenticator(cql3::query_processor&, ::service::raft_group0_client&, ::service::migration_manager&, utils::alien_worker&);
     ~certificate_authenticator();
 
     future<> start() override;

auth/common.cc

@@ -94,7 +94,7 @@ static future<> create_legacy_metadata_table_if_missing_impl(
         try {
             co_return co_await mm.announce(co_await ::service::prepare_new_column_family_announcement(qp.proxy(), table, ts),
                     std::move(group0_guard), format("auth: create {} metadata table", table->cf_name()));
-        } catch (const exceptions::already_exists_exception&) {}
+        } catch (exceptions::already_exists_exception&) {}
     }
 }
 

auth/common.hh

@@ -48,10 +48,6 @@ extern constinit const std::string_view AUTH_PACKAGE_NAME;
 
 } // namespace meta
 
-constexpr std::string_view PERMISSIONS_CF = "role_permissions";
-constexpr std::string_view ROLE_MEMBERS_CF = "role_members";
-constexpr std::string_view ROLE_ATTRIBUTES_CF = "role_attributes";
-
 // This is a helper to check whether auth-v2 is on.
 bool legacy_mode(cql3::query_processor& qp);
 

auth/default_authorizer.cc

@@ -37,6 +37,7 @@ std::string_view default_authorizer::qualified_java_name() const {
 static constexpr std::string_view ROLE_NAME = "role";
 static constexpr std::string_view RESOURCE_NAME = "resource";
 static constexpr std::string_view PERMISSIONS_NAME = "permissions";
+static constexpr std::string_view PERMISSIONS_CF = "role_permissions";
 
 static logging::logger alogger("default_authorizer");
 
@@ -256,7 +257,7 @@ future<> default_authorizer::revoke_all(std::string_view role_name, ::service::g
         } else {
             co_await collect_mutations(_qp, mc, query, {sstring(role_name)});
         }
-    } catch (const exceptions::request_execution_exception& e) {
+    } catch (exceptions::request_execution_exception& e) {
         alogger.warn("CassandraAuthorizer failed to revoke all permissions of {}: {}", role_name, e);
     }
 }
@@ -293,13 +294,13 @@ future<> default_authorizer::revoke_all_legacy(const resource& resource) {
                                 [resource](auto ep) {
                     try {
                         std::rethrow_exception(ep);
-                    } catch (const exceptions::request_execution_exception& e) {
+                    } catch (exceptions::request_execution_exception& e) {
                         alogger.warn("CassandraAuthorizer failed to revoke all permissions on {}: {}", resource, e);
                     }
 
                 });
             });
-        } catch (const exceptions::request_execution_exception& e) {
+        } catch (exceptions::request_execution_exception& e) {
             alogger.warn("CassandraAuthorizer failed to revoke all permissions on {}: {}", resource, e);
             return make_ready_future();
         }

auth/ldap_role_manager.cc

@@ -83,18 +83,17 @@ static const class_registrator<
     ldap_role_manager,
     cql3::query_processor&,
     ::service::raft_group0_client&,
-    ::service::migration_manager&,
-    cache&> registration(ldap_role_manager_full_name);
+    ::service::migration_manager&> registration(ldap_role_manager_full_name);
 
 ldap_role_manager::ldap_role_manager(
         std::string_view query_template, std::string_view target_attr, std::string_view bind_name, std::string_view bind_password,
-        cql3::query_processor& qp, ::service::raft_group0_client& rg0c, ::service::migration_manager& mm, cache& cache)
-        : _std_mgr(qp, rg0c, mm, cache), _group0_client(rg0c), _query_template(query_template), _target_attr(target_attr), _bind_name(bind_name)
+        cql3::query_processor& qp, ::service::raft_group0_client& rg0c, ::service::migration_manager& mm)
+        : _std_mgr(qp, rg0c, mm), _group0_client(rg0c), _query_template(query_template), _target_attr(target_attr), _bind_name(bind_name)
         , _bind_password(bind_password)
         , _connection_factory(bind(std::mem_fn(&ldap_role_manager::reconnect), std::ref(*this))) {
 }
 
-ldap_role_manager::ldap_role_manager(cql3::query_processor& qp, ::service::raft_group0_client& rg0c, ::service::migration_manager& mm, cache& cache)
+ldap_role_manager::ldap_role_manager(cql3::query_processor& qp, ::service::raft_group0_client& rg0c, ::service::migration_manager& mm)
     : ldap_role_manager(
             qp.db().get_config().ldap_url_template(),
             qp.db().get_config().ldap_attr_role(),
@@ -102,8 +101,7 @@ ldap_role_manager::ldap_role_manager(cql3::query_processor& qp, ::service::raft_
             qp.db().get_config().ldap_bind_passwd(),
             qp,
             rg0c,
-            mm,
-            cache) {
+            mm) {
 }
 
 std::string_view ldap_role_manager::qualified_java_name() const noexcept {

auth/ldap_role_manager.hh

@@ -14,7 +14,6 @@
 
 #include "ent/ldap/ldap_connection.hh"
 #include "standard_role_manager.hh"
-#include "auth/cache.hh"
 
 namespace auth {
 
@@ -44,13 +43,12 @@ class ldap_role_manager : public role_manager {
             std::string_view bind_password, ///< LDAP bind credentials.
             cql3::query_processor& qp, ///< Passed to standard_role_manager.
             ::service::raft_group0_client& rg0c, ///< Passed to standard_role_manager.
-            ::service::migration_manager& mm, ///< Passed to standard_role_manager.
-            cache& cache ///< Passed to standard_role_manager.
+            ::service::migration_manager& mm ///< Passed to standard_role_manager.
     );
 
     /// Retrieves LDAP configuration entries from qp and invokes the other constructor.  Required by
     /// class_registrator<role_manager>.
-    ldap_role_manager(cql3::query_processor& qp, ::service::raft_group0_client& rg0c, ::service::migration_manager& mm, cache& cache);
+    ldap_role_manager(cql3::query_processor& qp, ::service::raft_group0_client& rg0c, ::service::migration_manager& mm);
 
     /// Thrown when query-template parsing fails.
     struct url_error : public std::runtime_error {

auth/maintenance_socket_role_manager.cc

@@ -11,7 +11,6 @@
 #include <seastar/core/future.hh>
 #include <stdexcept>
 #include <string_view>
-#include "auth/cache.hh"
 #include "cql3/description.hh"
 #include "utils/class_registrator.hh"
 
@@ -24,8 +23,7 @@ static const class_registrator<
         maintenance_socket_role_manager,
         cql3::query_processor&,
         ::service::raft_group0_client&,
-        ::service::migration_manager&,
-        cache&> registration(sstring{maintenance_socket_role_manager_name});
+        ::service::migration_manager&> registration(sstring{maintenance_socket_role_manager_name});
 
 
 std::string_view maintenance_socket_role_manager::qualified_java_name() const noexcept {

auth/maintenance_socket_role_manager.hh

@@ -8,7 +8,6 @@
 
 #pragma once
 
-#include "auth/cache.hh"
 #include "auth/resource.hh"
 #include "auth/role_manager.hh"
 #include <seastar/core/future.hh>
@@ -30,7 +29,7 @@ extern const std::string_view maintenance_socket_role_manager_name;
 // system_auth keyspace, which may be not yet created when the maintenance socket starts listening.
 class maintenance_socket_role_manager final : public role_manager {
 public:
-    maintenance_socket_role_manager(cql3::query_processor&, ::service::raft_group0_client&, ::service::migration_manager&, cache&) {}
+    maintenance_socket_role_manager(cql3::query_processor&, ::service::raft_group0_client&, ::service::migration_manager&) {}
 
     virtual std::string_view qualified_java_name() const noexcept override;
 

auth/password_authenticator.cc

@@ -49,7 +49,6 @@ static const class_registrator<
         cql3::query_processor&,
         ::service::raft_group0_client&,
         ::service::migration_manager&,
-        cache&,
         utils::alien_worker&> password_auth_reg("org.apache.cassandra.auth.PasswordAuthenticator");
 
 static thread_local auto rng_for_salt = std::default_random_engine(std::random_device{}());
@@ -64,11 +63,10 @@ std::string password_authenticator::default_superuser(const db::config& cfg) {
 password_authenticator::~password_authenticator() {
 }
 
-password_authenticator::password_authenticator(cql3::query_processor& qp, ::service::raft_group0_client& g0, ::service::migration_manager& mm, cache& cache, utils::alien_worker& hashing_worker)
+password_authenticator::password_authenticator(cql3::query_processor& qp, ::service::raft_group0_client& g0, ::service::migration_manager& mm, utils::alien_worker& hashing_worker)
     : _qp(qp)
     , _group0_client(g0)
     , _migration_manager(mm)
-    , _cache(cache)
     , _stopped(make_ready_future<>()) 
     , _superuser(default_superuser(qp.db().get_config()))
     , _hashing_worker(hashing_worker)
@@ -317,33 +315,24 @@ future<authenticated_user> password_authenticator::authenticate(
     const sstring password = credentials.at(PASSWORD_KEY);
 
     try {
-        std::optional<sstring> salted_hash;
-        if (legacy_mode(_qp)) {
-            salted_hash = co_await get_password_hash(username);
-            if (!salted_hash) {
-                throw exceptions::authentication_exception("Username and/or password are incorrect");
-            }
-        } else {
-            auto role = _cache.get(username);
-            if (!role || role->salted_hash.empty()) {
-                throw exceptions::authentication_exception("Username and/or password are incorrect");
-            }
-            salted_hash = role->salted_hash;
+        const std::optional<sstring> salted_hash = co_await get_password_hash(username);
+        if (!salted_hash) {
+            throw exceptions::authentication_exception("Username and/or password are incorrect");
         }
-        const bool password_match = co_await _hashing_worker.submit<bool>([password = std::move(password), salted_hash] {
+        const bool password_match = co_await _hashing_worker.submit<bool>([password = std::move(password), salted_hash = std::move(salted_hash)]{
             return passwords::check(password, *salted_hash);
         });
         if (!password_match) {
             throw exceptions::authentication_exception("Username and/or password are incorrect");
         }
         co_return username;
-    } catch (const std::system_error &) {
+    } catch (std::system_error &) {
         std::throw_with_nested(exceptions::authentication_exception("Could not verify password"));
-    } catch (const exceptions::request_execution_exception& e) {
+    } catch (exceptions::request_execution_exception& e) {
         std::throw_with_nested(exceptions::authentication_exception(e.what()));
-    } catch (const exceptions::authentication_exception& e) {
+    } catch (exceptions::authentication_exception& e) {
         std::throw_with_nested(e);
-    } catch (const exceptions::unavailable_exception& e) {
+    } catch (exceptions::unavailable_exception& e) {
         std::throw_with_nested(exceptions::authentication_exception(e.get_message()));
     } catch (...) {
         std::throw_with_nested(exceptions::authentication_exception("authentication failed"));

auth/password_authenticator.hh

@@ -16,7 +16,6 @@
 #include "db/consistency_level_type.hh"
 #include "auth/authenticator.hh"
 #include "auth/passwords.hh"
-#include "auth/cache.hh"
 #include "service/raft/raft_group0_client.hh"
 #include "utils/alien_worker.hh"
 
@@ -42,7 +41,6 @@ class password_authenticator : public authenticator {
     cql3::query_processor& _qp;
     ::service::raft_group0_client& _group0_client;
     ::service::migration_manager& _migration_manager;
-    cache& _cache;
     future<> _stopped;
     abort_source _as;
     std::string _superuser; // default superuser name from the config (may or may not be present in roles table)
@@ -55,7 +53,7 @@ public:
     static db::consistency_level consistency_for_user(std::string_view role_name);
     static std::string default_superuser(const db::config&);
 
-    password_authenticator(cql3::query_processor&, ::service::raft_group0_client&, ::service::migration_manager&, cache&, utils::alien_worker&);
+    password_authenticator(cql3::query_processor&, ::service::raft_group0_client&, ::service::migration_manager&, utils::alien_worker&);
 
     ~password_authenticator();
 

auth/saslauthd_authenticator.cc

@@ -35,10 +35,9 @@ static const class_registrator<
         cql3::query_processor&,
         ::service::raft_group0_client&,
         ::service::migration_manager&,
-        cache&,
         utils::alien_worker&> saslauthd_auth_reg("com.scylladb.auth.SaslauthdAuthenticator");
 
-saslauthd_authenticator::saslauthd_authenticator(cql3::query_processor& qp, ::service::raft_group0_client&, ::service::migration_manager&, cache&, utils::alien_worker&)
+saslauthd_authenticator::saslauthd_authenticator(cql3::query_processor& qp, ::service::raft_group0_client&, ::service::migration_manager&, utils::alien_worker&)
     : _socket_path(qp.db().get_config().saslauthd_socket_path())
 {}
 

auth/saslauthd_authenticator.hh

@@ -11,7 +11,6 @@
 #pragma once
 
 #include "auth/authenticator.hh"
-#include "auth/cache.hh"
 #include "utils/alien_worker.hh"
 
 namespace cql3 {
@@ -30,7 +29,7 @@ namespace auth {
 class saslauthd_authenticator : public authenticator {
     sstring _socket_path; ///< Path to the domain socket on which saslauthd is listening.
 public:
-    saslauthd_authenticator(cql3::query_processor&, ::service::raft_group0_client&, ::service::migration_manager&, cache&,utils::alien_worker&);
+    saslauthd_authenticator(cql3::query_processor&, ::service::raft_group0_client&, ::service::migration_manager&, utils::alien_worker&);
 
     future<> start() override;
 

auth/service.cc

@@ -17,7 +17,6 @@
 #include <chrono>
 
 #include <seastar/core/future-util.hh>
-#include <seastar/core/shard_id.hh>
 #include <seastar/core/sharded.hh>
 #include <seastar/core/shared_ptr.hh>
 
@@ -158,7 +157,6 @@ static future<> validate_role_exists(const service& ser, std::string_view role_n
 
 service::service(
         utils::loading_cache_config c,
-        cache& cache,
         cql3::query_processor& qp,
         ::service::raft_group0_client& g0,
         ::service::migration_notifier& mn,
@@ -168,7 +166,6 @@ service::service(
         maintenance_socket_enabled used_by_maintenance_socket)
             : _loading_cache_config(std::move(c))
             , _permissions_cache(nullptr)
-            , _cache(cache)
             , _qp(qp)
             , _group0_client(g0)
             , _mnotifier(mn)
@@ -191,17 +188,15 @@ service::service(
         ::service::migration_manager& mm,
         const service_config& sc,
         maintenance_socket_enabled used_by_maintenance_socket,
-        cache& cache,
         utils::alien_worker& hashing_worker)
             : service(
                       std::move(c),
-                      cache,
                       qp,
                       g0,
                       mn,
                       create_object<authorizer>(sc.authorizer_java_name, qp, g0, mm),
-                      create_object<authenticator>(sc.authenticator_java_name, qp, g0, mm, cache, hashing_worker),
-                      create_object<role_manager>(sc.role_manager_java_name, qp, g0, mm, cache),
+                      create_object<authenticator>(sc.authenticator_java_name, qp, g0, mm, hashing_worker),
+                      create_object<role_manager>(sc.role_manager_java_name, qp, g0, mm),
                       used_by_maintenance_socket) {
 }
 
@@ -226,7 +221,7 @@ future<> service::create_legacy_keyspace_if_missing(::service::migration_manager
             try {
                 co_return co_await mm.announce(::service::prepare_new_keyspace_announcement(db.real_database(), ksm, ts),
                         std::move(group0_guard), seastar::format("auth_service: create {} keyspace", meta::legacy::AUTH_KS));
-            } catch (const ::service::group0_concurrent_modification&) {
+            } catch (::service::group0_concurrent_modification&) {
                 log.info("Concurrent operation is detected while creating {} keyspace, retrying.", meta::legacy::AUTH_KS);
             }
         }
@@ -237,9 +232,6 @@ future<> service::start(::service::migration_manager& mm, db::system_keyspace& s
     auto auth_version = co_await sys_ks.get_auth_version();
     // version is set in query processor to be easily available in various places we call auth::legacy_mode check.
     _qp.auth_version = auth_version;
-    if (this_shard_id() == 0) {
-        co_await _cache.load_all();
-    }
     if (!_used_by_maintenance_socket) {
         // this legacy keyspace is only used by cqlsh
         // it's needed when executing `list roles` or `list users`

auth/service.hh

@@ -21,7 +21,6 @@
 #include "auth/authorizer.hh"
 #include "auth/permission.hh"
 #include "auth/permissions_cache.hh"
-#include "auth/cache.hh"
 #include "auth/role_manager.hh"
 #include "auth/common.hh"
 #include "cql3/description.hh"
@@ -78,7 +77,6 @@ public:
 class service final : public seastar::peering_sharded_service<service> {
     utils::loading_cache_config _loading_cache_config;
     std::unique_ptr<permissions_cache> _permissions_cache;
-    cache& _cache;
 
     cql3::query_processor& _qp;
 
@@ -109,7 +107,6 @@ class service final : public seastar::peering_sharded_service<service> {
 public:
     service(
             utils::loading_cache_config,
-            cache& cache,
             cql3::query_processor&,
             ::service::raft_group0_client&,
             ::service::migration_notifier&,
@@ -131,7 +128,6 @@ public:
             ::service::migration_manager&,
             const service_config&,
             maintenance_socket_enabled,
-            cache&,
             utils::alien_worker&);
 
     future<> start(::service::migration_manager&, db::system_keyspace&);

auth/standard_role_manager.cc

@@ -41,6 +41,21 @@
 
 namespace auth {
 
+namespace meta {
+
+namespace role_members_table {
+
+constexpr std::string_view name{"role_members" , 12};
+
+}
+
+namespace role_attributes_table {
+
+constexpr std::string_view name{"role_attributes", 15};
+
+}
+
+}
 
 static logging::logger log("standard_role_manager");
 
@@ -49,8 +64,7 @@ static const class_registrator<
         standard_role_manager,
         cql3::query_processor&,
         ::service::raft_group0_client&,
-        ::service::migration_manager&,
-        cache&> registration("org.apache.cassandra.auth.CassandraRoleManager");
+        ::service::migration_manager&> registration("org.apache.cassandra.auth.CassandraRoleManager");
 
 struct record final {
     sstring name;
@@ -107,11 +121,10 @@ static bool has_can_login(const cql3::untyped_result_set_row& row) {
     return row.has("can_login") && !(boolean_type->deserialize(row.get_blob_unfragmented("can_login")).is_null());
 }
 
-standard_role_manager::standard_role_manager(cql3::query_processor& qp, ::service::raft_group0_client& g0, ::service::migration_manager& mm, cache& cache)
+standard_role_manager::standard_role_manager(cql3::query_processor& qp, ::service::raft_group0_client& g0, ::service::migration_manager& mm)
     : _qp(qp)
     , _group0_client(g0)
     , _migration_manager(mm)
-    , _cache(cache)
     , _stopped(make_ready_future<>())
     , _superuser(password_authenticator::default_superuser(qp.db().get_config()))
 {}
@@ -123,7 +136,7 @@ std::string_view standard_role_manager::qualified_java_name() const noexcept {
 const resource_set& standard_role_manager::protected_resources() const {
     static const resource_set resources({
             make_data_resource(meta::legacy::AUTH_KS, meta::roles_table::name),
-            make_data_resource(meta::legacy::AUTH_KS, ROLE_MEMBERS_CF)});
+            make_data_resource(meta::legacy::AUTH_KS, meta::role_members_table::name)});
 
     return resources;
 }
@@ -147,7 +160,7 @@ future<> standard_role_manager::create_legacy_metadata_tables_if_missing() const
             "  PRIMARY KEY (role, member)"
             ")",
             meta::legacy::AUTH_KS,
-            ROLE_MEMBERS_CF);
+            meta::role_members_table::name);
     static const sstring create_role_attributes_query = seastar::format(
             "CREATE TABLE {}.{} ("
             "  role text,"
@@ -156,7 +169,7 @@ future<> standard_role_manager::create_legacy_metadata_tables_if_missing() const
             "  PRIMARY KEY(role, name)"
             ")",
             meta::legacy::AUTH_KS,
-            ROLE_ATTRIBUTES_CF);
+            meta::role_attributes_table::name);
     return when_all_succeed(
             create_legacy_metadata_table_if_missing(
                     meta::roles_table::name,
@@ -164,12 +177,12 @@ future<> standard_role_manager::create_legacy_metadata_tables_if_missing() const
                     create_roles_query,
                     _migration_manager),
             create_legacy_metadata_table_if_missing(
-                    ROLE_MEMBERS_CF,
+                    meta::role_members_table::name,
                     _qp,
                     create_role_members_query,
                     _migration_manager),
             create_legacy_metadata_table_if_missing(
-                    ROLE_ATTRIBUTES_CF,
+                    meta::role_attributes_table::name,
                     _qp,
                     create_role_attributes_query,
                     _migration_manager)).discard_result();
@@ -192,7 +205,7 @@ future<> standard_role_manager::legacy_create_default_role_if_missing() {
                 {_superuser},
                 cql3::query_processor::cache_internal::no).discard_result();
         log.info("Created default superuser role '{}'.", _superuser);
-    } catch (const exceptions::unavailable_exception& e) {
+    } catch(const exceptions::unavailable_exception& e) {
         log.warn("Skipped default role setup: some nodes were not ready; will retry");
         throw e;
     }
@@ -416,7 +429,7 @@ future<> standard_role_manager::drop(std::string_view role_name, ::service::grou
     const auto revoke_from_members = [this, role_name, &mc] () -> future<> {
         const sstring query = seastar::format("SELECT member FROM {}.{} WHERE role = ?",
                 get_auth_ks_name(_qp),
-                ROLE_MEMBERS_CF);
+                meta::role_members_table::name);
         const auto members = co_await _qp.execute_internal(
                 query,
                 consistency_for_role(role_name),
@@ -448,7 +461,7 @@ future<> standard_role_manager::drop(std::string_view role_name, ::service::grou
     const auto remove_attributes_of = [this, role_name, &mc] () -> future<> {
         const sstring query = seastar::format("DELETE FROM {}.{} WHERE role = ?",
                 get_auth_ks_name(_qp),
-                ROLE_ATTRIBUTES_CF);
+                meta::role_attributes_table::name);
         if (legacy_mode(_qp)) {
             co_await _qp.execute_internal(query, {sstring(role_name)},
                 cql3::query_processor::cache_internal::yes).discard_result();
@@ -504,7 +517,7 @@ standard_role_manager::legacy_modify_membership(
             case membership_change::add: {
                 const sstring insert_query = seastar::format("INSERT INTO {}.{} (role, member) VALUES (?, ?)",
                         get_auth_ks_name(_qp),
-                        ROLE_MEMBERS_CF);
+                        meta::role_members_table::name);
                 co_return co_await _qp.execute_internal(
                         insert_query,
                         consistency_for_role(role_name),
@@ -516,7 +529,7 @@ standard_role_manager::legacy_modify_membership(
             case membership_change::remove: {
                 const sstring delete_query = seastar::format("DELETE FROM {}.{} WHERE role = ? AND member = ?",
                         get_auth_ks_name(_qp),
-                        ROLE_MEMBERS_CF);
+                        meta::role_members_table::name);
                 co_return co_await _qp.execute_internal(
                         delete_query,
                         consistency_for_role(role_name),
@@ -554,12 +567,12 @@ standard_role_manager::modify_membership(
     case membership_change::add:
         modify_role_members = seastar::format("INSERT INTO {}.{} (role, member) VALUES (?, ?)",
                 get_auth_ks_name(_qp),
-                ROLE_MEMBERS_CF);
+                meta::role_members_table::name);
         break;
     case membership_change::remove:
         modify_role_members = seastar::format("DELETE FROM {}.{} WHERE role = ? AND member = ?",
                 get_auth_ks_name(_qp),
-                ROLE_MEMBERS_CF);
+                meta::role_members_table::name);
         break;
     default:
         on_internal_error(log, format("unknown membership_change value: {}", int(ch)));
@@ -653,7 +666,7 @@ future<role_set> standard_role_manager::query_granted(std::string_view grantee_n
 future<role_to_directly_granted_map> standard_role_manager::query_all_directly_granted(::service::query_state& qs) {
     const sstring query = seastar::format("SELECT * FROM {}.{}",
             get_auth_ks_name(_qp),
-            ROLE_MEMBERS_CF);
+            meta::role_members_table::name);
 
     const auto results = co_await _qp.execute_internal(
             query,
@@ -718,21 +731,15 @@ future<bool> standard_role_manager::is_superuser(std::string_view role_name) {
 }
 
 future<bool> standard_role_manager::can_login(std::string_view role_name) {
-    if (legacy_mode(_qp)) {
-       const auto r = co_await require_record(_qp, role_name);
-       co_return r.can_login;
-    }
-    auto role = _cache.get(sstring(role_name));
-    if (!role) {
-        throw nonexistant_role(role_name);
-    }
-    co_return role->can_login;
+    return require_record(_qp, role_name).then([](record r) {
+        return r.can_login;
+    });
 }
 
 future<std::optional<sstring>> standard_role_manager::get_attribute(std::string_view role_name, std::string_view attribute_name, ::service::query_state& qs) {
     const sstring query = seastar::format("SELECT name, value FROM {}.{} WHERE role = ? AND name = ?",
             get_auth_ks_name(_qp),
-            ROLE_ATTRIBUTES_CF);
+            meta::role_attributes_table::name);
     const auto result_set = co_await _qp.execute_internal(query, db::consistency_level::ONE, qs, {sstring(role_name), sstring(attribute_name)}, cql3::query_processor::cache_internal::yes);
     if (!result_set->empty()) {
         const cql3::untyped_result_set_row &row = result_set->one();
@@ -763,7 +770,7 @@ future<> standard_role_manager::set_attribute(std::string_view role_name, std::s
     }
     const sstring query = seastar::format("INSERT INTO {}.{} (role, name, value)  VALUES (?, ?, ?)",
             get_auth_ks_name(_qp),
-            ROLE_ATTRIBUTES_CF);
+            meta::role_attributes_table::name);
     if (legacy_mode(_qp)) {
         co_await _qp.execute_internal(query, {sstring(role_name), sstring(attribute_name), sstring(attribute_value)}, cql3::query_processor::cache_internal::yes).discard_result();
     } else {
@@ -778,7 +785,7 @@ future<> standard_role_manager::remove_attribute(std::string_view role_name, std
     }
     const sstring query = seastar::format("DELETE FROM {}.{} WHERE role = ? AND name = ?",
             get_auth_ks_name(_qp),
-            ROLE_ATTRIBUTES_CF);
+            meta::role_attributes_table::name);
     if (legacy_mode(_qp)) {
         co_await _qp.execute_internal(query, {sstring(role_name), sstring(attribute_name)}, cql3::query_processor::cache_internal::yes).discard_result();
     } else {

auth/standard_role_manager.hh

@@ -10,7 +10,6 @@
 
 #include "auth/common.hh"
 #include "auth/role_manager.hh"
-#include "auth/cache.hh"
 
 #include <string_view>
 
@@ -37,14 +36,13 @@ class standard_role_manager final : public role_manager {
     cql3::query_processor& _qp;
     ::service::raft_group0_client& _group0_client;
     ::service::migration_manager& _migration_manager;
-    cache& _cache;
     future<> _stopped;
     abort_source _as;
     std::string _superuser;
     shared_promise<> _superuser_created_promise;
 
 public:
-    standard_role_manager(cql3::query_processor&, ::service::raft_group0_client&, ::service::migration_manager&, cache&);
+    standard_role_manager(cql3::query_processor&, ::service::raft_group0_client&, ::service::migration_manager&);
 
     virtual std::string_view qualified_java_name() const noexcept override;
 

auth/transitional.cc

@@ -13,7 +13,6 @@
 #include "auth/authorizer.hh"
 #include "auth/default_authorizer.hh"
 #include "auth/password_authenticator.hh"
-#include "auth/cache.hh"
 #include "auth/permission.hh"
 #include "service/raft/raft_group0_client.hh"
 #include "utils/class_registrator.hh"
@@ -38,8 +37,8 @@ class transitional_authenticator : public authenticator {
 public:
     static const sstring PASSWORD_AUTHENTICATOR_NAME;
 
-    transitional_authenticator(cql3::query_processor& qp, ::service::raft_group0_client& g0, ::service::migration_manager& mm, cache& cache, utils::alien_worker& hashing_worker)
-            : transitional_authenticator(std::make_unique<password_authenticator>(qp, g0, mm, cache, hashing_worker)) {
+    transitional_authenticator(cql3::query_processor& qp, ::service::raft_group0_client& g0, ::service::migration_manager& mm, utils::alien_worker& hashing_worker)
+            : transitional_authenticator(std::make_unique<password_authenticator>(qp, g0, mm, hashing_worker)) {
     }
     transitional_authenticator(std::unique_ptr<authenticator> a)
             : _authenticator(std::move(a)) {
@@ -81,7 +80,7 @@ public:
         }).handle_exception([](auto ep) {
             try {
                 std::rethrow_exception(ep);
-            } catch (const exceptions::authentication_exception&) {
+            } catch (exceptions::authentication_exception&) {
                 // return anon user
                 return make_ready_future<authenticated_user>(anonymous_user());
             }
@@ -126,7 +125,7 @@ public:
             virtual bytes evaluate_response(bytes_view client_response) override {
                 try {
                     return _sasl->evaluate_response(client_response);
-                } catch (const exceptions::authentication_exception&) {
+                } catch (exceptions::authentication_exception&) {
                     _complete = true;
                     return {};
                 }
@@ -141,7 +140,7 @@ public:
                     return _sasl->get_authenticated_user().handle_exception([](auto ep) {
                         try {
                             std::rethrow_exception(ep);
-                        } catch (const exceptions::authentication_exception&) {
+                        } catch (exceptions::authentication_exception&) {
                             // return anon user
                             return make_ready_future<authenticated_user>(anonymous_user());
                         }
@@ -241,7 +240,6 @@ static const class_registrator<
         cql3::query_processor&,
         ::service::raft_group0_client&,
         ::service::migration_manager&,
-        auth::cache&,
         utils::alien_worker&> transitional_authenticator_reg(auth::PACKAGE_NAME + "TransitionalAuthenticator");
 
 static const class_registrator<

backlog_controller.hh

@@ -15,7 +15,6 @@
 #include <cmath>
 
 #include "seastarx.hh"
-#include "backlog_controller_fwd.hh"
 
 // Simple proportional controller to adjust shares for processes for which a backlog can be clearly
 // defined.
@@ -129,21 +128,11 @@ public:
     static constexpr unsigned normalization_factor = 30;
     static constexpr float disable_backlog = std::numeric_limits<double>::infinity();
     static constexpr float backlog_disabled(float backlog) { return std::isinf(backlog); }
-    static inline const std::vector<backlog_controller::control_point> default_control_points = {
-            backlog_controller::control_point{0.0, 50}, {1.5, 100}, {normalization_factor, default_compaction_maximum_shares}};
-    compaction_controller(backlog_controller::scheduling_group sg, float static_shares, std::optional<float> max_shares,
-        std::chrono::milliseconds interval, std::function<float()> current_backlog)
+    compaction_controller(backlog_controller::scheduling_group sg, float static_shares, std::chrono::milliseconds interval, std::function<float()> current_backlog)
         : backlog_controller(std::move(sg), std::move(interval),
-          default_control_points,
+          std::vector<backlog_controller::control_point>({{0.0, 50}, {1.5, 100} , {normalization_factor, 1000}}),
           std::move(current_backlog),
           static_shares
         )
-    {
-        if (max_shares) {
-            set_max_shares(*max_shares);
-        }
-    }
-
-    // Updates the maximum output value for control points.
-    void set_max_shares(float max_shares);
+    {}
 };

backlog_controller_fwd.hh

@@ -1,13 +0,0 @@
-/*
- * Copyright (C) 2025-present ScyllaDB
- */
-
-/*
- * SPDX-License-Identifier: LicenseRef-ScyllaDB-Source-Available-1.0
- */
-
-#pragma once
-
-#include <cstdint>
-
-static constexpr uint64_t default_compaction_maximum_shares = 1000;

cdc/CMakeLists.txt

@@ -17,8 +17,5 @@ target_link_libraries(cdc
   PRIVATE
     replica)
 
-if (Scylla_USE_PRECOMPILED_HEADER_USE)
-  target_precompile_headers(cdc REUSE_FROM scylla-precompiled-header)
-endif()
 check_headers(check-headers cdc
   GLOB_RECURSE ${CMAKE_CURRENT_SOURCE_DIR}/*.hh)

cdc/log.cc

@@ -25,7 +25,6 @@
 #include "locator/abstract_replication_strategy.hh"
 #include "locator/topology.hh"
 #include "replica/database.hh"
-#include "db/config.hh"
 #include "db/schema_tables.hh"
 #include "gms/feature_service.hh"
 #include "schema/schema.hh"
@@ -587,9 +586,11 @@ bytes log_data_column_deleted_elements_name_bytes(const bytes& column_name) {
     return to_bytes(cdc_deleted_elements_column_prefix) + column_name;
 }
 
-static void set_default_properties_log_table(schema_builder& b, const schema& s,
-        const replica::database& db, const keyspace_metadata& ksm)
+static schema_ptr create_log_schema(const schema& s, const replica::database& db,
+        const keyspace_metadata& ksm, api::timestamp_type timestamp, std::optional<table_id> uuid, schema_ptr old)
 {
+    schema_builder b(s.ks_name(), log_name(s.cf_name()));
+    b.with_partitioner(cdc::cdc_partitioner::classname);
     b.set_compaction_strategy(compaction::compaction_strategy_type::time_window);
     b.set_comment(fmt::format("CDC log for {}.{}", s.ks_name(), s.cf_name()));
     auto ttl_seconds = s.cdc_options().ttl();
@@ -615,22 +616,13 @@ static void set_default_properties_log_table(schema_builder& b, const schema& s,
                         std::to_string(std::max(1, window_seconds / 2))},
         });
     }
-    b.set_caching_options(caching_options::get_disabled_caching_options());
-
-    auto rs = generate_replication_strategy(ksm, db.get_token_metadata().get_topology());
-    auto tombstone_gc_ext = seastar::make_shared<tombstone_gc_extension>(get_default_tombstone_gc_mode(*rs, db.get_token_metadata(), false));
-    b.add_extension(tombstone_gc_extension::NAME, std::move(tombstone_gc_ext));
-}
-
-static void add_columns_to_cdc_log(schema_builder& b, const schema& s,
-        const api::timestamp_type timestamp, const schema_ptr old)
-{
     b.with_column(log_meta_column_name_bytes("stream_id"), bytes_type, column_kind::partition_key);
     b.with_column(log_meta_column_name_bytes("time"), timeuuid_type, column_kind::clustering_key);
     b.with_column(log_meta_column_name_bytes("batch_seq_no"), int32_type, column_kind::clustering_key);
     b.with_column(log_meta_column_name_bytes("operation"), data_type_for<operation_native_type>());
     b.with_column(log_meta_column_name_bytes("ttl"), long_type);
     b.with_column(log_meta_column_name_bytes("end_of_batch"), boolean_type);
+    b.set_caching_options(caching_options::get_disabled_caching_options());
 
     auto validate_new_column = [&] (const sstring& name) {
         // When dropping a column from a CDC log table, we set the drop timestamp to be
@@ -700,28 +692,15 @@ static void add_columns_to_cdc_log(schema_builder& b, const schema& s,
     add_columns(s.clustering_key_columns());
     add_columns(s.static_columns(), true);
     add_columns(s.regular_columns(), true);
-}
-
-static schema_ptr create_log_schema(const schema& s, const replica::database& db,
-        const keyspace_metadata& ksm, api::timestamp_type timestamp, std::optional<table_id> uuid, schema_ptr old)
-{
-    schema_builder b(s.ks_name(), log_name(s.cf_name()));
-
-    b.with_partitioner(cdc::cdc_partitioner::classname);
-
-    if (old) {
-        // If the user reattaches the log table, do not change its properties.
-        b.set_properties(old->get_properties());
-    } else {
-        set_default_properties_log_table(b, s, db, ksm);
-    }
-
-    add_columns_to_cdc_log(b, s, timestamp, old);
 
     if (uuid) {
         b.set_uuid(*uuid);
     }
 
+    auto rs = generate_replication_strategy(ksm, db.get_token_metadata().get_topology());
+    auto tombstone_gc_ext = seastar::make_shared<tombstone_gc_extension>(get_default_tombstone_gc_mode(*rs, db.get_token_metadata()));
+    b.add_extension(tombstone_gc_extension::NAME, std::move(tombstone_gc_ext));
+
     /**
      * #10473 - if we are redefining the log table, we need to ensure any dropped
      * columns are registered in "dropped_columns" table, otherwise clients will not
@@ -952,6 +931,9 @@ static managed_bytes merge(const abstract_type& type, const managed_bytes_opt& p
     throw std::runtime_error(format("cdc merge: unknown type {}", type.name()));
 }
 
+using cell_map = std::unordered_map<const column_definition*, managed_bytes_opt>;
+using row_states_map = std::unordered_map<clustering_key, cell_map, clustering_key::hashing, clustering_key::equality>;
+
 static managed_bytes_opt get_col_from_row_state(const cell_map* state, const column_definition& cdef) {
     if (state) {
         if (auto it = state->find(&cdef); it != state->end()) {
@@ -961,12 +943,7 @@ static managed_bytes_opt get_col_from_row_state(const cell_map* state, const col
     return std::nullopt;
 }
 
-cell_map* get_row_state(row_states_map& row_states, const clustering_key& ck) {
-    auto it = row_states.find(ck);
-    return it == row_states.end() ? nullptr : &it->second;
-}
-
-const cell_map* get_row_state(const row_states_map& row_states, const clustering_key& ck) {
+static cell_map* get_row_state(row_states_map& row_states, const clustering_key& ck) {
     auto it = row_states.find(ck);
     return it == row_states.end() ? nullptr : &it->second;
 }
@@ -1436,8 +1413,6 @@ struct process_change_visitor {
     row_states_map& _clustering_row_states;
     cell_map& _static_row_state;
 
-    const bool _is_update = false;
-
     const bool _generate_delta_values = true;
 
     void static_row_cells(auto&& visit_row_cells) {
@@ -1461,13 +1436,12 @@ struct process_change_visitor {
 
         struct clustering_row_cells_visitor : public process_row_visitor {
             operation _cdc_op = operation::update;
-            operation _marker_op = operation::insert;
 
             using process_row_visitor::process_row_visitor;
 
             void marker(const row_marker& rm) {
                 _ttl_column = get_ttl(rm);
-                _cdc_op = _marker_op;
+                _cdc_op = operation::insert;
             }
         };
 
@@ -1475,9 +1449,6 @@ struct process_change_visitor {
                 log_ck, _touched_parts, _builder,
                 _enable_updating_state, &ckey, get_row_state(_clustering_row_states, ckey),
                 _clustering_row_states, _generate_delta_values);
-        if (_is_update && _request_options.alternator) {
-            v._marker_op = operation::update;
-        }
         visit_row_cells(v);
 
         if (_enable_updating_state) {
@@ -1631,11 +1602,6 @@ private:
 
     row_states_map _clustering_row_states;
     cell_map _static_row_state;
-    // True if the mutated row existed before applying the mutation. In other
-    // words, if the preimage is enabled and it isn't empty (otherwise, we
-    // assume that the row is non-existent). Used for Alternator Streams (see
-    // #6918).
-    bool _is_update = false;
 
     const bool _uses_tablets;
 
@@ -1762,7 +1728,6 @@ public:
             ._enable_updating_state = _enable_updating_state,
             ._clustering_row_states = _clustering_row_states,
             ._static_row_state = _static_row_state,
-            ._is_update = _is_update,
             ._generate_delta_values = generate_delta_values(_builder->base_schema())
         };
         cdc::inspect_mutation(m, v);
@@ -1773,10 +1738,6 @@ public:
         _builder->end_record();
     }
 
-    const row_states_map& clustering_row_states() const override {
-        return _clustering_row_states;
-    }
-
     // Takes and returns generated cdc log mutations and associated statistics about parts touched during transformer's lifetime.
     // The `transformer` object on which this method was called on should not be used anymore.
     std::tuple<utils::chunked_vector<mutation>, stats::part_type_set> finish() && {
@@ -1900,7 +1861,6 @@ public:
                     _static_row_state[&c] = std::move(*maybe_cell_view);
                 }
             }
-            _is_update = true;
         }
 
         if (static_only) {
@@ -1988,7 +1948,6 @@ cdc::cdc_service::impl::augment_mutation_call(lowres_clock::time_point timeout,
                 return make_ready_future<>();
             }
 
-            const bool alternator_increased_compatibility = options.alternator && options.alternator_streams_increased_compatibility;
             transformer trans(_ctxt, s, m.decorated_key(), options);
 
             auto f = make_ready_future<lw_shared_ptr<cql3::untyped_result_set>>(nullptr);
@@ -1996,7 +1955,7 @@ cdc::cdc_service::impl::augment_mutation_call(lowres_clock::time_point timeout,
                 // Preimage has been fetched by upper layers.
                 tracing::trace(tr_state, "CDC: Using a prefetched preimage");
                 f = make_ready_future<lw_shared_ptr<cql3::untyped_result_set>>(options.preimage);
-            } else if (s->cdc_options().preimage() || s->cdc_options().postimage() || alternator_increased_compatibility) {
+            } else if (s->cdc_options().preimage() || s->cdc_options().postimage()) {
                 // Note: further improvement here would be to coalesce the pre-image selects into one
                 // if a batch contains several modifications to the same table. Otoh, batch is rare(?)
                 // so this is premature.
@@ -2013,7 +1972,7 @@ cdc::cdc_service::impl::augment_mutation_call(lowres_clock::time_point timeout,
                 tracing::trace(tr_state, "CDC: Preimage not enabled for the table, not querying current value of {}", m.decorated_key());
             }
 
-            return f.then([alternator_increased_compatibility, trans = std::move(trans), &mutations, idx, tr_state, &details, &options] (lw_shared_ptr<cql3::untyped_result_set> rs) mutable {
+            return f.then([trans = std::move(trans), &mutations, idx, tr_state, &details] (lw_shared_ptr<cql3::untyped_result_set> rs) mutable {
                 auto& m = mutations[idx];
                 auto& s = m.schema();
 
@@ -2028,13 +1987,13 @@ cdc::cdc_service::impl::augment_mutation_call(lowres_clock::time_point timeout,
                 details.had_preimage |= preimage;
                 details.had_postimage |= postimage;
                 tracing::trace(tr_state, "CDC: Generating log mutations for {}", m.decorated_key());
-                if (should_split(m, options)) {
+                if (should_split(m)) {
                     tracing::trace(tr_state, "CDC: Splitting {}", m.decorated_key());
                     details.was_split = true;
-                    process_changes_with_splitting(m, trans, preimage, postimage, alternator_increased_compatibility);
+                    process_changes_with_splitting(m, trans, preimage, postimage);
                 } else {
                     tracing::trace(tr_state, "CDC: No need to split {}", m.decorated_key());
-                    process_changes_without_splitting(m, trans, preimage, postimage, alternator_increased_compatibility);
+                    process_changes_without_splitting(m, trans, preimage, postimage);
                 }
                 auto [log_mut, touched_parts] = std::move(trans).finish();
                 const int generated_count = log_mut.size();

cdc/log.hh

@@ -52,9 +52,6 @@ class database;
 
 namespace cdc {
 
-using cell_map = std::unordered_map<const column_definition*, managed_bytes_opt>;
-using row_states_map = std::unordered_map<clustering_key, cell_map, clustering_key::hashing, clustering_key::equality>;
-
 // cdc log table operation
 enum class operation : int8_t {
     // note: these values will eventually be read by a third party, probably not privvy to this
@@ -76,14 +73,6 @@ struct per_request_options {
     // Scylla. Currently, only TTL expiration implementation for Alternator
     // uses this.
     const bool is_system_originated = false;
-    // True if this mutation was emitted by Alternator.
-    const bool alternator = false;
-    // Sacrifice performance for the sake of better compatibility with DynamoDB
-    // Streams. It's important for correctness that
-    // alternator_streams_increased_compatibility config flag be read once per
-    // request, because it's live-updateable. As a result, the flag may change
-    // between reads.
-    const bool alternator_streams_increased_compatibility = false;
 };
 
 struct operation_result_tracker;
@@ -153,7 +142,4 @@ bool is_cdc_metacolumn_name(const sstring& name);
 
 utils::UUID generate_timeuuid(api::timestamp_type t);
 
-cell_map* get_row_state(row_states_map& row_states, const clustering_key& ck);
-const cell_map* get_row_state(const row_states_map& row_states, const clustering_key& ck);
-
 } // namespace cdc

cdc/split.cc

@@ -6,28 +6,15 @@
  * SPDX-License-Identifier: LicenseRef-ScyllaDB-Source-Available-1.0
  */
 
-#include "bytes.hh"
-#include "bytes_fwd.hh"
-#include "mutation/atomic_cell.hh"
-#include "mutation/atomic_cell_or_collection.hh"
-#include "mutation/collection_mutation.hh"
 #include "mutation/mutation.hh"
-#include "mutation/tombstone.hh"
 #include "schema/schema.hh"
 
-#include "seastar/core/sstring.hh"
 #include "types/concrete_types.hh"
-#include "types/types.hh"
 #include "types/user.hh"
 
 #include "split.hh"
 #include "log.hh"
 #include "change_visitor.hh"
-#include "utils/managed_bytes.hh"
-#include <string_view>
-#include <unordered_map>
-
-extern logging::logger cdc_log;
 
 struct atomic_column_update {
     column_id id;
@@ -503,8 +490,6 @@ struct should_split_visitor {
     // Otherwise we store the change's ttl.
     std::optional<gc_clock::duration> _ttl = std::nullopt;
 
-    virtual ~should_split_visitor() = default;
-
     inline bool finished() const { return _result; }
     inline void stop() { _result = true; }
 
@@ -527,7 +512,7 @@ struct should_split_visitor {
 
     void collection_tombstone(const tombstone& t) { visit(t.timestamp + 1); }
 
-    virtual void live_collection_cell(bytes_view, const atomic_cell_view& cell) {
+    void live_collection_cell(bytes_view, const atomic_cell_view& cell) {
         if (_had_row_marker) {
             // nonatomic updates cannot be expressed with an INSERT.
             return stop();
@@ -537,7 +522,7 @@ struct should_split_visitor {
     void dead_collection_cell(bytes_view, const atomic_cell_view& cell) { visit(cell); }
     void collection_column(const column_definition&, auto&& visit_collection) { visit_collection(*this); }
 
-    virtual void marker(const row_marker& rm) {
+    void marker(const row_marker& rm) {
         _had_row_marker = true;
         visit(rm.timestamp(), get_ttl(rm));
     }
@@ -578,29 +563,7 @@ struct should_split_visitor {
     }
 };
 
-// This is the same as the above, but it doesn't split a row marker away from
-// an update. As a result, updates that create an item appear as a single log
-// row.
-class alternator_should_split_visitor : public should_split_visitor {
-public:
-    ~alternator_should_split_visitor() override = default;
-
-    void live_collection_cell(bytes_view, const atomic_cell_view& cell) override {
-        visit(cell.timestamp());
-    }
-
-    void marker(const row_marker& rm) override {
-        visit(rm.timestamp());
-    }
-};
-
-bool should_split(const mutation& m, const per_request_options& options) {
-    if (options.alternator) {
-        alternator_should_split_visitor v;
-        cdc::inspect_mutation(m, v);
-        return v._result || v._ts == api::missing_timestamp;
-    }
-
+bool should_split(const mutation& m) {
     should_split_visitor v;
 
     cdc::inspect_mutation(m, v);
@@ -610,109 +573,8 @@ bool should_split(const mutation& m, const per_request_options& options) {
         || v._ts == api::missing_timestamp;
 }
 
-// Returns true if the row state and the atomic and nonatomic entries represent
-// an equivalent item.
-static bool entries_match_row_state(const schema_ptr& base_schema, const cell_map& row_state, const std::vector<atomic_column_update>& atomic_entries,
-        std::vector<nonatomic_column_update>& nonatomic_entries) {
-    for (const auto& update : atomic_entries) {
-        const column_definition& cdef = base_schema->column_at(column_kind::regular_column, update.id);
-        const auto it = row_state.find(&cdef);
-        if (it == row_state.end()) {
-            return false;
-        }
-        if (to_managed_bytes_opt(update.cell.value().linearize()) != it->second) {
-            return false;
-        }
-    }
-    if (nonatomic_entries.empty()) {
-        return true;
-    }
-
-    for (const auto& update : nonatomic_entries) {
-        const column_definition& cdef = base_schema->column_at(column_kind::regular_column, update.id);
-        const auto it = row_state.find(&cdef);
-        if (it == row_state.end()) {
-            return false;
-        }
-
-        // The only collection used by Alternator is a non-frozen map.
-        auto current_raw_map = cdef.type->deserialize(*it->second);
-        map_type_impl::native_type current_values = value_cast<map_type_impl::native_type>(current_raw_map);
-
-        if (current_values.size() != update.cells.size()) {
-            return false;
-        }
-        
-        std::unordered_map<sstring_view, bytes> current_values_map;
-        for (const auto& entry : current_values) {
-            const auto attr_name = std::string_view(value_cast<sstring>(entry.first));
-            current_values_map[attr_name] = value_cast<bytes>(entry.second);
-        }
-
-        for (const auto& [key, value] : update.cells) {
-            const auto key_str = to_string_view(key);
-            if (!value.is_live()) {
-                if (current_values_map.contains(key_str)) {
-                    return false;
-                }
-            } else if (current_values_map[key_str] != value.value().linearize()) {
-                return false;
-            }
-        }
-    }
-    return true;
-}
-
-bool should_skip(batch& changes, const mutation& base_mutation, change_processor& processor) {
-    const schema_ptr& base_schema = base_mutation.schema();
-    // Alternator doesn't use static updates and clustered range deletions.
-    if (!changes.static_updates.empty() || !changes.clustered_range_deletions.empty()) {
-        return false;
-    }
-
-    for (clustered_row_insert& u : changes.clustered_inserts) {
-        const cell_map* row_state = get_row_state(processor.clustering_row_states(), u.key);
-        if (!row_state) {
-            return false;
-        }
-        if (!entries_match_row_state(base_schema, *row_state, u.atomic_entries, u.nonatomic_entries)) {
-            return false;
-        }
-    }
-
-    for (clustered_row_update& u : changes.clustered_updates) {
-        const cell_map* row_state = get_row_state(processor.clustering_row_states(), u.key);
-        if (!row_state) {
-            return false;
-        }
-        if (!entries_match_row_state(base_schema, *row_state, u.atomic_entries, u.nonatomic_entries)) {
-            return false;
-        }
-    }
-
-    // Skip only if the row being deleted does not exist (i.e. the deletion is a no-op).
-    for (const auto& row_deletion : changes.clustered_row_deletions) {
-        if (processor.clustering_row_states().contains(row_deletion.key)) {
-            return false;
-        }
-    }
-
-    // Don't skip if the item exists.
-    //
-    // Increased DynamoDB Streams compatibility guarantees that single-item
-    // operations will read the item and store it in the clustering row states.
-    // If it is not found there, we may skip CDC. This is safe as long as the
-    // assumptions of this operation's write isolation are not violated.
-    if (changes.partition_deletions && processor.clustering_row_states().contains(clustering_key::make_empty())) {
-        return false;
-    }
-
-    cdc_log.trace("Skipping CDC log for mutation {}", base_mutation);
-    return true;
-}
-
 void process_changes_with_splitting(const mutation& base_mutation, change_processor& processor,
-        bool enable_preimage, bool enable_postimage, bool alternator_strict_compatibility) {
+        bool enable_preimage, bool enable_postimage) {
     const auto base_schema = base_mutation.schema();
     auto changes = extract_changes(base_mutation);
     auto pk = base_mutation.key();
@@ -724,6 +586,9 @@ void process_changes_with_splitting(const mutation& base_mutation, change_proces
     const auto last_timestamp = changes.rbegin()->first;
 
     for (auto& [change_ts, btch] : changes) {
+        const bool is_last = change_ts == last_timestamp;
+        processor.begin_timestamp(change_ts, is_last);
+
         clustered_column_set affected_clustered_columns_per_row{clustering_key::less_compare(*base_schema)};
         one_kind_column_set affected_static_columns{base_schema->static_columns_count()};
 
@@ -732,12 +597,6 @@ void process_changes_with_splitting(const mutation& base_mutation, change_proces
             affected_clustered_columns_per_row = btch.get_affected_clustered_columns_per_row(*base_mutation.schema());
         }
 
-        if (alternator_strict_compatibility && should_skip(btch, base_mutation, processor)) {
-            continue;
-        }
-
-        const bool is_last = change_ts == last_timestamp;
-        processor.begin_timestamp(change_ts, is_last);
         if (enable_preimage) {
             if (affected_static_columns.count() > 0) {
                 processor.produce_preimage(nullptr, affected_static_columns);
@@ -825,13 +684,7 @@ void process_changes_with_splitting(const mutation& base_mutation, change_proces
 }
 
 void process_changes_without_splitting(const mutation& base_mutation, change_processor& processor,
-        bool enable_preimage, bool enable_postimage, bool alternator_strict_compatibility) {
-    if (alternator_strict_compatibility) {
-        auto changes = extract_changes(base_mutation);
-        if (should_skip(changes.begin()->second, base_mutation, processor)) {
-            return;
-        }
-    }
+        bool enable_preimage, bool enable_postimage) {
     auto ts = find_timestamp(base_mutation);
     processor.begin_timestamp(ts, true);
 

cdc/split.hh

@@ -9,7 +9,6 @@
 #pragma once
 
 #include <boost/dynamic_bitset.hpp>  // IWYU pragma: keep
-#include "cdc/log.hh"
 #include "replica/database_fwd.hh"
 #include "mutation/timestamp.hh"
 
@@ -66,14 +65,12 @@ public:
     // Tells processor we have reached end of record - last part
     // of a given timestamp batch
     virtual void end_record() = 0;
-
-    virtual const row_states_map& clustering_row_states() const = 0;
 };
 
-bool should_split(const mutation& base_mutation, const per_request_options& options);
+bool should_split(const mutation& base_mutation);
 void process_changes_with_splitting(const mutation& base_mutation, change_processor& processor,
-        bool enable_preimage, bool enable_postimage, bool alternator_strict_compatibility);
+        bool enable_preimage, bool enable_postimage);
 void process_changes_without_splitting(const mutation& base_mutation, change_processor& processor,
-        bool enable_preimage, bool enable_postimage, bool alternator_strict_compatibility);
+        bool enable_preimage, bool enable_postimage);
 
 }

compaction/CMakeLists.txt

@@ -21,8 +21,5 @@ target_link_libraries(compaction
     mutation_writer
     replica)
 
-if (Scylla_USE_PRECOMPILED_HEADER_USE)
-  target_precompile_headers(compaction REUSE_FROM scylla-precompiled-header)
-endif()
 check_headers(check-headers compaction
   GLOB_RECURSE ${CMAKE_CURRENT_SOURCE_DIR}/*.hh)

compaction/compaction_manager.cc

@@ -867,8 +867,8 @@ auto fmt::formatter<compaction::compaction_task_executor>::format(const compacti
 
 namespace compaction {
 
-inline compaction_controller make_compaction_controller(const compaction_manager::scheduling_group& csg, uint64_t static_shares, std::optional<float> max_shares, std::function<double()> fn) {
-    return compaction_controller(csg, static_shares, max_shares, 250ms, std::move(fn));
+inline compaction_controller make_compaction_controller(const compaction_manager::scheduling_group& csg, uint64_t static_shares, std::function<double()> fn) {
+    return compaction_controller(csg, static_shares, 250ms, std::move(fn));
 }
 
 compaction::compaction_state::~compaction_state() {
@@ -1014,7 +1014,7 @@ compaction_manager::compaction_manager(config cfg, abort_source& as, tasks::task
     , _sys_ks("compaction_manager::system_keyspace")
     , _cfg(std::move(cfg))
     , _compaction_submission_timer(compaction_sg(), compaction_submission_callback())
-    , _compaction_controller(make_compaction_controller(compaction_sg(), static_shares(), _cfg.max_shares.get(), [this] () -> float {
+    , _compaction_controller(make_compaction_controller(compaction_sg(), static_shares(), [this] () -> float {
         _last_backlog = backlog();
         auto b = _last_backlog / available_memory();
         // This means we are using an unimplemented strategy
@@ -1033,10 +1033,6 @@ compaction_manager::compaction_manager(config cfg, abort_source& as, tasks::task
     , _throughput_updater(serialized_action([this] { return update_throughput(throughput_mbs()); }))
     , _update_compaction_static_shares_action([this] { return update_static_shares(static_shares()); })
     , _compaction_static_shares_observer(_cfg.static_shares.observe(_update_compaction_static_shares_action.make_observer()))
-    , _compaction_max_shares_observer(_cfg.max_shares.observe([this] (const float& max_shares) {
-        cmlog.info("Updating max shares to {}", max_shares);
-        _compaction_controller.set_max_shares(max_shares);
-    }))
     , _strategy_control(std::make_unique<strategy_control>(*this))
     , _tombstone_gc_state(_shared_tombstone_gc_state) {
     tm.register_module(_task_manager_module->get_name(), _task_manager_module);
@@ -1055,12 +1051,11 @@ compaction_manager::compaction_manager(tasks::task_manager& tm)
     , _sys_ks("compaction_manager::system_keyspace")
     , _cfg(config{ .available_memory = 1 })
     , _compaction_submission_timer(compaction_sg(), compaction_submission_callback())
-    , _compaction_controller(make_compaction_controller(compaction_sg(), 1, std::nullopt, [] () -> float { return 1.0; }))
+    , _compaction_controller(make_compaction_controller(compaction_sg(), 1, [] () -> float { return 1.0; }))
     , _backlog_manager(_compaction_controller)
     , _throughput_updater(serialized_action([this] { return update_throughput(throughput_mbs()); }))
     , _update_compaction_static_shares_action([] { return make_ready_future<>(); })
     , _compaction_static_shares_observer(_cfg.static_shares.observe(_update_compaction_static_shares_action.make_observer()))
-    , _compaction_max_shares_observer(_cfg.max_shares.observe([] (const float& max_shares) {}))
     , _strategy_control(std::make_unique<strategy_control>(*this))
     , _tombstone_gc_state(_shared_tombstone_gc_state) {
     tm.register_module(_task_manager_module->get_name(), _task_manager_module);

compaction/compaction_manager.hh

@@ -80,7 +80,6 @@ public:
         scheduling_group maintenance_sched_group;
         size_t available_memory = 0;
         utils::updateable_value<float> static_shares = utils::updateable_value<float>(0);
-        utils::updateable_value<float> max_shares = utils::updateable_value<float>(0);
         utils::updateable_value<uint32_t> throughput_mb_per_sec = utils::updateable_value<uint32_t>(0);
         std::chrono::seconds flush_all_tables_before_major = std::chrono::duration_cast<std::chrono::seconds>(std::chrono::days(1));
     };
@@ -160,7 +159,6 @@ private:
     std::optional<utils::observer<uint32_t>> _throughput_option_observer;
     serialized_action _update_compaction_static_shares_action;
     utils::observer<float> _compaction_static_shares_observer;
-    utils::observer<float> _compaction_max_shares_observer;
     uint64_t _validation_errors = 0;
 
     class strategy_control;
@@ -293,10 +291,6 @@ public:
         return _cfg.static_shares.get();
     }
 
-    float max_shares() const noexcept {
-        return _cfg.max_shares.get();
-    }
-
     uint32_t throughput_mbs() const noexcept {
         return _cfg.throughput_mb_per_sec.get();
     }

compaction/task_manager_module.cc

@@ -227,7 +227,7 @@ future<> run_table_tasks(replica::database& db, std::vector<table_tasks_info> ta
                 // Tables will be kept in descending order.
                 std::ranges::sort(table_tasks, std::greater<>(), [&] (const table_tasks_info& tti) {
                     try {
-                        return db.find_column_family(tti.ti.id).get_stats().live_disk_space_used.on_disk;
+                        return db.find_column_family(tti.ti.id).get_stats().live_disk_space_used;
                     } catch (const replica::no_such_column_family& e) {
                         return int64_t(-1);
                     }
@@ -281,7 +281,7 @@ future<> run_keyspace_tasks(replica::database& db, std::vector<keyspace_tasks_in
                     try {
                         return std::accumulate(kti.table_infos.begin(), kti.table_infos.end(), int64_t(0), [&] (int64_t sum, const table_info& t) {
                             try {
-                                sum += db.find_column_family(t.id).get_stats().live_disk_space_used.on_disk;
+                                sum += db.find_column_family(t.id).get_stats().live_disk_space_used;
                             } catch (const replica::no_such_column_family&) {
                                 // ignore
                             }

conf/scylla.yaml

@@ -888,18 +888,9 @@ rf_rack_valid_keyspaces: false
 #
 # Vector Store options
 #
-# HTTP and HTTPS schemes are supported. Port number is mandatory.
-# If both `vector_store_primary_uri` and `vector_store_secondary_uri` are unset or empty, vector search is disabled.
-#
-# A comma-separated list of primary vector store node URIs. These nodes are preferred for vector search operations.
+# A comma-separated list of URIs for the vector store using DNS name. Only HTTP schema is supported. Port number is mandatory.
+# Default is empty, which means that the vector store is not used.
 # vector_store_primary_uri: http://vector-store.dns.name:{port}
-#
-# A comma-separated list of secondary vector store node URIs. These nodes are used as a fallback when all primary nodes are unavailable, and are typically located in a different availability zone for high availability.
-# vector_store_secondary_uri: http://vector-store.dns.name:{port}
-#
-# Options for encrypted connections to the vector store. These options are used for HTTPS URIs in vector_store_primary_uri and vector_store_secondary_uri.
-# vector_store_encryption_options:
-#    truststore: <not set, use system trust>
 
 # 
 # io-streaming rate limiting

configure.py

@@ -445,7 +445,6 @@ ldap_tests = set([
 scylla_tests = set([
     'test/boost/combined_tests',
     'test/boost/UUID_test',
-    'test/boost/url_parse_test',
     'test/boost/advanced_rpc_compressor_test',
     'test/boost/allocation_strategy_test',
     'test/boost/alternator_unit_test',
@@ -647,28 +646,6 @@ vector_search_tests = set([
     'test/vector_search/client_test'
 ])
 
-vector_search_validator_bin = 'vector-search-validator/bin/vector-search-validator'
-vector_search_validator_deps = set([
-    'test/vector_search_validator/build-validator',
-    'test/vector_search_validator/Cargo.toml',
-    'test/vector_search_validator/crates/validator/Cargo.toml',
-    'test/vector_search_validator/crates/validator/src/main.rs',
-    'test/vector_search_validator/crates/validator-scylla/Cargo.toml',
-    'test/vector_search_validator/crates/validator-scylla/src/lib.rs',
-    'test/vector_search_validator/crates/validator-scylla/src/cql.rs',
-])
-
-vector_store_bin = 'vector-search-validator/bin/vector-store'
-vector_store_deps = set([
-    'test/vector_search_validator/build-env',
-    'test/vector_search_validator/build-vector-store',
-])
-
-vector_search_validator_bins = set([
-    vector_search_validator_bin,
-    vector_store_bin,
-])
-
 wasms = set([
     'wasm/return_input.wat',
     'wasm/test_complex_null_values.wat',
@@ -702,7 +679,7 @@ other = set([
     'iotune',
 ])
 
-all_artifacts = apps | cpp_apps | tests | other | wasms | vector_search_validator_bins
+all_artifacts = apps | cpp_apps | tests | other | wasms
 
 arg_parser = argparse.ArgumentParser('Configure scylla', add_help=False, formatter_class=argparse.ArgumentDefaultsHelpFormatter)
 arg_parser.add_argument('--out', dest='buildfile', action='store', default='build.ninja',
@@ -786,7 +763,6 @@ arg_parser.add_argument('--use-cmake', action=argparse.BooleanOptionalAction, de
 arg_parser.add_argument('--coverage', action = 'store_true', help = 'Compile scylla with coverage instrumentation')
 arg_parser.add_argument('--build-dir', action='store', default='build',
                         help='Build directory path')
-arg_parser.add_argument('--disable-precompiled-header', action='store_true', default=False, help='Disable precompiled header for scylla binary')
 arg_parser.add_argument('-h', '--help', action='store_true', help='show this help message and exit')
 args = arg_parser.parse_args()
 if args.help:
@@ -1062,6 +1038,7 @@ scylla_core = (['message/messaging_service.cc',
                 'db/hints/resource_manager.cc',
                 'db/hints/sync_point.cc',
                 'db/large_data_handler.cc',
+                'db/legacy_schema_migrator.cc',
                 'db/marshal/type_parser.cc',
                 'db/per_partition_rate_limit_options.cc',
                 'db/rate_limiter.cc',
@@ -1195,7 +1172,6 @@ scylla_core = (['message/messaging_service.cc',
                 'auth/allow_all_authorizer.cc',
                 'auth/authenticated_user.cc',
                 'auth/authenticator.cc',
-                'auth/cache.cc',
                 'auth/common.cc',
                 'auth/default_authorizer.cc',
                 'auth/resource.cc',
@@ -1292,8 +1268,7 @@ scylla_core = (['message/messaging_service.cc',
                 'vector_search/vector_store_client.cc',
                 'vector_search/dns.cc',
                 'vector_search/client.cc',
-                'vector_search/clients.cc',
-                'vector_search/truststore.cc'
+                'vector_search/clients.cc'
                 ] + [Antlr3Grammar('cql3/Cql.g')] \
                   + scylla_raft_core
                )
@@ -1604,7 +1579,6 @@ deps['test/boost/combined_tests'] += [
     'test/boost/query_processor_test.cc',
     'test/boost/reader_concurrency_semaphore_test.cc',
     'test/boost/repair_test.cc',
-    'test/boost/replicator_test.cc',
     'test/boost/restrictions_test.cc',
     'test/boost/role_manager_test.cc',
     'test/boost/row_cache_test.cc',
@@ -1647,7 +1621,6 @@ deps['test/boost/bytes_ostream_test'] = [
 ]
 deps['test/boost/input_stream_test'] = ['test/boost/input_stream_test.cc']
 deps['test/boost/UUID_test'] = ['clocks-impl.cc', 'utils/UUID_gen.cc', 'test/boost/UUID_test.cc', 'utils/uuid.cc', 'utils/dynamic_bitset.cc', 'utils/hashers.cc', 'utils/on_internal_error.cc']
-deps['test/boost/url_parse_test'] = ['utils/http.cc', 'test/boost/url_parse_test.cc', ]
 deps['test/boost/murmur_hash_test'] = ['bytes.cc', 'utils/murmur_hash.cc', 'test/boost/murmur_hash_test.cc']
 deps['test/boost/allocation_strategy_test'] = ['test/boost/allocation_strategy_test.cc', 'utils/logalloc.cc', 'utils/dynamic_bitset.cc', 'utils/labels.cc']
 deps['test/boost/log_heap_test'] = ['test/boost/log_heap_test.cc']
@@ -2212,15 +2185,7 @@ if os.path.exists(kmipc_lib):
     user_cflags += f' -I{kmipc_dir}/include -DHAVE_KMIP'
 
 def get_extra_cxxflags(mode, mode_config, cxx, debuginfo):
-    cxxflags = [
-        # we need this flag for correct precompiled header handling in connection with ccache (or similar)
-        # `git` tools don't preserve timestamps, so when using ccache it might be possible to add pch to ccache
-        # and then later (after for example rebase) get `stdafx.hh` with different timestamp, but the same content.
-        # this will tell ccache to bring pch from its cache. Later on clang will check if timestamps match and complain.
-        # Adding `-fpch-validate-input-files-content` tells clang to check content of stdafx.hh if timestamps don't match.
-        # The flag seems to be present in gcc as well.
-        "" if args.disable_precompiled_header else '-fpch-validate-input-files-content'
-    ]
+    cxxflags = []
 
     optimization_level = mode_config['optimization-level']
     cxxflags.append(f'-O{optimization_level}')
@@ -2285,7 +2250,6 @@ def write_build_file(f,
                      scylla_version,
                      scylla_release,
                      args):
-    use_precompiled_header = not args.disable_precompiled_header
     warnings = get_warning_options(args.cxx)
     rustc_target = pick_rustc_target('wasm32-wasi', 'wasm32-wasip1')
     f.write(textwrap.dedent('''\
@@ -2392,10 +2356,7 @@ def write_build_file(f,
 
     for mode in build_modes:
         modeval = modes[mode]
-        seastar_lib_ext = 'so' if modeval['build_seastar_shared_libs'] else 'a'
-        seastar_dep = f'$builddir/{mode}/seastar/libseastar.{seastar_lib_ext}'
-        seastar_testing_dep = f'$builddir/{mode}/seastar/libseastar_testing.{seastar_lib_ext}'
-        abseil_dep = ' '.join(f'$builddir/{mode}/abseil/{lib}' for lib in abseil_libs)
+
         fmt_lib = 'fmt'
         f.write(textwrap.dedent('''\
             cxx_ld_flags_{mode} = {cxx_ld_flags}
@@ -2408,14 +2369,6 @@ def write_build_file(f,
               command = $cxx -MD -MT $out -MF $out.d {seastar_cflags} $cxxflags_{mode} $cxxflags $obj_cxxflags -c -o $out $in
               description = CXX $out
               depfile = $out.d
-            rule cxx_build_precompiled_header.{mode}
-              command = $cxx -MD -MT $out -MF $out.d {seastar_cflags} $cxxflags_{mode} $cxxflags $obj_cxxflags -c -o $out $in -Winvalid-pch -fpch-instantiate-templates -Xclang -emit-pch -DSCYLLA_USE_PRECOMPILED_HEADER
-              description = CXX-PRECOMPILED-HEADER $out
-              depfile = $out.d
-            rule cxx_with_pch.{mode}
-              command = $cxx -MD -MT $out -MF $out.d {seastar_cflags} $cxxflags_{mode} $cxxflags $obj_cxxflags -c -o $out $in -Winvalid-pch -Xclang -include-pch -Xclang $builddir/{mode}/stdafx.hh.pch
-              description = CXX $out
-              depfile = $out.d
             rule link.{mode}
               command = $cxx  $ld_flags_{mode} $ldflags -o $out $in $libs $libs_{mode}
               description = LINK $out
@@ -2449,7 +2402,7 @@ def write_build_file(f,
                         $builddir/{mode}/gen/${{stem}}Parser.cpp
                 description = ANTLR3 $in
             rule checkhh.{mode}
-              command = $cxx -MD -MT $out -MF $out.d {seastar_cflags} $cxxflags $cxxflags_{mode} $obj_cxxflags --include $in -c -o $out $builddir/{mode}/gen/empty.cc -USCYLLA_USE_PRECOMPILED_HEADER
+              command = $cxx -MD -MT $out -MF $out.d {seastar_cflags} $cxxflags $cxxflags_{mode} $obj_cxxflags --include $in -c -o $out $builddir/{mode}/gen/empty.cc
               description = CHECKHH $in
               depfile = $out.d
             rule test.{mode}
@@ -2463,11 +2416,10 @@ def write_build_file(f,
               description = RUST_LIB $out
             ''').format(mode=mode, antlr3_exec=args.antlr3_exec, fmt_lib=fmt_lib, test_repeat=args.test_repeat, test_timeout=args.test_timeout, **modeval))
         f.write(
-            'build {mode}-build: phony {artifacts} {wasms} {vector_search_validator_bins}\n'.format(
+            'build {mode}-build: phony {artifacts} {wasms}\n'.format(
                 mode=mode,
-                artifacts=str.join(' ', ['$builddir/' + mode + '/' + x for x in sorted(build_artifacts - wasms - vector_search_validator_bins)]),
+                artifacts=str.join(' ', ['$builddir/' + mode + '/' + x for x in sorted(build_artifacts - wasms)]),
                 wasms = str.join(' ', ['$builddir/' + x for x in sorted(build_artifacts & wasms)]),
-                vector_search_validator_bins=str.join(' ', ['$builddir/' + x for x in sorted(build_artifacts & vector_search_validator_bins)]),
             )
         )
         if profile_recipe := modes[mode].get('profile_recipe'):
@@ -2476,7 +2428,6 @@ def write_build_file(f,
         include_dist_target = f'dist-{mode}' if args.enable_dist is None or args.enable_dist else ''
         f.write(f'build {mode}: phony {include_cxx_target} {include_dist_target}\n')
         compiles = {}
-        compiles_with_pch = set()
         swaggers = set()
         serializers = {}
         ragels = {}
@@ -2491,16 +2442,16 @@ def write_build_file(f,
         # object code. And we enable LTO when linking the main Scylla executable, while disable
         # it when linking anything else.
 
+        seastar_lib_ext = 'so' if modeval['build_seastar_shared_libs'] else 'a'
         for binary in sorted(build_artifacts):
             if modeval['is_profile'] and binary != "scylla":
                 # Just to avoid clutter in build.ninja
                 continue
             profile_dep = modes[mode].get('profile_target', "")
 
-            if binary in other or binary in wasms or binary in vector_search_validator_bins:
+            if binary in other or binary in wasms:
                 continue
             srcs = deps[binary]
-            # 'scylla'
             objs = ['$builddir/' + mode + '/' + src.replace('.cc', '.o')
                     for src in srcs
                     if src.endswith('.cc')]
@@ -2536,6 +2487,9 @@ def write_build_file(f,
                 continue
 
             do_lto = modes[mode]['has_lto'] and binary in lto_binaries
+            seastar_dep = f'$builddir/{mode}/seastar/libseastar.{seastar_lib_ext}'
+            seastar_testing_dep = f'$builddir/{mode}/seastar/libseastar_testing.{seastar_lib_ext}'
+            abseil_dep = ' '.join(f'$builddir/{mode}/abseil/{lib}' for lib in abseil_libs)
             seastar_testing_libs = f'$seastar_testing_libs_{mode}'
 
             local_libs = f'$seastar_libs_{mode} $libs'
@@ -2545,7 +2499,6 @@ def write_build_file(f,
                 local_libs += ' -flto=thin -ffat-lto-objects'
             else:
                 local_libs += ' -fno-lto'
-            use_pch = use_precompiled_header and binary == 'scylla'
             if binary in tests:
                 if binary in pure_boost_tests:
                     local_libs += ' ' + maybe_static(args.staticboost, '-lboost_unit_test_framework')
@@ -2574,8 +2527,6 @@ def write_build_file(f,
                 if src.endswith('.cc'):
                     obj = '$builddir/' + mode + '/' + src.replace('.cc', '.o')
                     compiles[obj] = src
-                    if use_pch:
-                        compiles_with_pch.add(obj)
                 elif src.endswith('.idl.hh'):
                     hh = '$builddir/' + mode + '/gen/' + src.replace('.idl.hh', '.dist.hh')
                     serializers[hh] = src
@@ -2608,11 +2559,10 @@ def write_build_file(f,
         )
 
         f.write(
-            'build {mode}-test: test.{mode} {test_executables} $builddir/{mode}/scylla {wasms} {vector_search_validator_bins} \n'.format(
+            'build {mode}-test: test.{mode} {test_executables} $builddir/{mode}/scylla {wasms}\n'.format(
                 mode=mode,
                 test_executables=' '.join(['$builddir/{}/{}'.format(mode, binary) for binary in sorted(tests)]),
                 wasms=' '.join([f'$builddir/{binary}' for binary in sorted(wasms)]),
-                vector_search_validator_bins=' '.join([f'$builddir/{binary}' for binary in sorted(vector_search_validator_bins)]),
             )
         )
         f.write(
@@ -2655,9 +2605,7 @@ def write_build_file(f,
             src = compiles[obj]
             seastar_dep = f'$builddir/{mode}/seastar/libseastar.{seastar_lib_ext}'
             abseil_dep = ' '.join(f'$builddir/{mode}/abseil/{lib}' for lib in abseil_libs)
-            pch_dep = f'$builddir/{mode}/stdafx.hh.pch' if obj in compiles_with_pch else ''
-            cxx_cmd = 'cxx_with_pch' if obj in compiles_with_pch else 'cxx'
-            f.write(f'build {obj}: {cxx_cmd}.{mode} {src} | {profile_dep} {seastar_dep} {abseil_dep} {gen_headers_dep} {pch_dep}\n')
+            f.write(f'build {obj}: cxx.{mode} {src} | {profile_dep} || {seastar_dep} {abseil_dep} {gen_headers_dep}\n')
             if src in modeval['per_src_extra_cxxflags']:
                 f.write('    cxxflags = {seastar_cflags} $cxxflags $cxxflags_{mode} {extra_cxxflags}\n'.format(mode=mode, extra_cxxflags=modeval["per_src_extra_cxxflags"][src], **modeval))
         for swagger in swaggers:
@@ -2718,8 +2666,6 @@ def write_build_file(f,
             f.write('  target = {lib}\n'.format(**locals()))
             f.write('  profile_dep = {profile_dep}\n'.format(**locals()))
 
-        f.write(f'build $builddir/{mode}/stdafx.hh.pch: cxx_build_precompiled_header.{mode} stdafx.hh | {profile_dep} {seastar_dep} {abseil_dep} {gen_headers_dep} {pch_dep}\n')
-
         f.write('build $builddir/{mode}/seastar/apps/iotune/iotune: ninja $builddir/{mode}/seastar/build.ninja | $builddir/{mode}/seastar/libseastar.{seastar_lib_ext}\n'
                 .format(**locals()))
         f.write('  pool = submodule_pool\n')
@@ -2783,19 +2729,6 @@ def write_build_file(f,
             'build compiler-training: phony {}\n'.format(' '.join(['{mode}-compiler-training'.format(mode=mode) for mode in default_modes]))
     )
 
-    f.write(textwrap.dedent(f'''\
-        rule build-vector-search-validator
-            command = test/vector_search_validator/build-validator $builddir
-        rule build-vector-store
-            command = test/vector_search_validator/build-vector-store $builddir
-        '''))
-    f.write(
-            'build $builddir/{vector_search_validator_bin}: build-vector-search-validator {}\n'.format(' '.join([dep for dep in sorted(vector_search_validator_deps)]), vector_search_validator_bin=vector_search_validator_bin)
-    )
-    f.write(
-            'build $builddir/{vector_store_bin}: build-vector-store {}\n'.format(' '.join([dep for dep in sorted(vector_store_deps)]), vector_store_bin=vector_store_bin)
-    )
-
     f.write(textwrap.dedent(f'''\
         build dist-unified-tar: phony {' '.join([f'$builddir/{mode}/dist/tar/{scylla_product}-unified-{scylla_version}-{scylla_release}.{arch}.tar.gz' for mode in default_modes])}
         build dist-unified: phony dist-unified-tar
@@ -3009,7 +2942,7 @@ def configure_using_cmake(args):
         'CMAKE_DEFAULT_CONFIGS': selected_configs,
         'CMAKE_C_COMPILER': args.cc,
         'CMAKE_CXX_COMPILER': args.cxx,
-        'CMAKE_CXX_FLAGS': args.user_cflags + ("" if args.disable_precompiled_header else " -fpch-validate-input-files-content"),
+        'CMAKE_CXX_FLAGS': args.user_cflags,
         'CMAKE_EXE_LINKER_FLAGS': args.user_ldflags,
         'CMAKE_EXPORT_COMPILE_COMMANDS': 'ON',
         'Scylla_CHECK_HEADERS': 'ON',
@@ -3018,7 +2951,6 @@ def configure_using_cmake(args):
         'Scylla_TEST_REPEAT': args.test_repeat,
         'Scylla_ENABLE_LTO': 'ON' if args.lto else 'OFF',
         'Scylla_WITH_DEBUG_INFO' : 'ON' if args.debuginfo else 'OFF',
-        'Scylla_USE_PRECOMPILED_HEADER': 'OFF' if args.disable_precompiled_header else 'ON',
     }
     if args.date_stamp:
         settings['Scylla_DATE_STAMP'] = args.date_stamp

cql3/CMakeLists.txt

@@ -138,8 +138,5 @@ target_link_libraries(cql3
     lang
     transport)
 
-if (Scylla_USE_PRECOMPILED_HEADER_USE)
-  target_precompile_headers(cql3 REUSE_FROM scylla-precompiled-header)
-endif()
 check_headers(check-headers cql3
   GLOB_RECURSE ${CMAKE_CURRENT_SOURCE_DIR}/*.hh)

cql3/Cql.g

@@ -575,15 +575,6 @@ usingTimeoutServiceLevelClauseObjective[std::unique_ptr<cql3::attributes::raw>&
     | serviceLevel sl_name=serviceLevelOrRoleName { attrs->service_level = std::move(sl_name); }
     ;
 
-usingTimeoutConcurrencyClause[std::unique_ptr<cql3::attributes::raw>& attrs]
-    : K_USING usingTimeoutConcurrencyClauseObjective[attrs] ( K_AND usingTimeoutConcurrencyClauseObjective[attrs] )*
-    ;
-
-usingTimeoutConcurrencyClauseObjective[std::unique_ptr<cql3::attributes::raw>& attrs]
-    : K_TIMEOUT to=term { attrs->timeout = std::move(to); }
-    | K_CONCURRENCY c=term { attrs->concurrency = std::move(c); }
-    ;
-
 /**
  * UPDATE <CF>
  * USING TIMESTAMP <long>
@@ -675,7 +666,7 @@ pruneMaterializedViewStatement returns [std::unique_ptr<raw::select_statement> e
         auto attrs = std::make_unique<cql3::attributes::raw>();
         expression wclause = conjunction{};
     }
-	: K_PRUNE K_MATERIALIZED K_VIEW cf=columnFamilyName (K_WHERE w=whereClause { wclause = std::move(w); } )? ( usingTimeoutConcurrencyClause[attrs] )?
+	: K_PRUNE K_MATERIALIZED K_VIEW cf=columnFamilyName (K_WHERE w=whereClause { wclause = std::move(w); } )? ( usingClause[attrs] )?
 	  {
 	        auto params = make_lw_shared<raw::select_statement::parameters>(std::move(orderings), is_distinct, allow_filtering, statement_subtype, bypass_cache);
 	        return std::make_unique<raw::select_statement>(std::move(cf), std::move(params),
@@ -1569,10 +1560,6 @@ serviceLevelOrRoleName returns [sstring name]
 | t=QUOTED_NAME        { $name = sstring($t.text); }
 | k=unreserved_keyword { $name = k;
 						 std::transform($name.begin(), $name.end(), $name.begin(), ::tolower);}
-// The literal `default` will not be parsed by any of the previous
-// rules, so we need to cover it manually. Needed by CREATE SERVICE
-// LEVEL and ATTACH SERVICE LEVEL.
-| t=K_DEFAULT          { $name = sstring("default"); }
 | QMARK {add_recognition_error("Bind variables cannot be used for service levels or role names");}
 ;
 
@@ -2379,7 +2366,6 @@ K_LIKE:        L I K E;
 
 K_TIMEOUT:     T I M E O U T;
 K_PRUNE:       P R U N E;
-K_CONCURRENCY: C O N C U R R E N C Y;
 
 K_EXECUTE:     E X E C U T E;
 

cql3/attributes.cc

@@ -20,21 +20,19 @@
 namespace cql3 {
 
 std::unique_ptr<attributes> attributes::none() {
-    return std::unique_ptr<attributes>{new attributes{{}, {}, {}, {}, {}}};
+    return std::unique_ptr<attributes>{new attributes{{}, {}, {}, {}}};
 }
 
 attributes::attributes(std::optional<cql3::expr::expression>&& timestamp,
                        std::optional<cql3::expr::expression>&& time_to_live,
                        std::optional<cql3::expr::expression>&& timeout,
-                       std::optional<sstring> service_level,
-                       std::optional<cql3::expr::expression>&& concurrency)
+                       std::optional<sstring> service_level)
     : _timestamp_unset_guard(timestamp)
     , _timestamp{std::move(timestamp)}
     , _time_to_live_unset_guard(time_to_live)
     , _time_to_live{std::move(time_to_live)}
     , _timeout{std::move(timeout)}
     , _service_level(std::move(service_level))
-    , _concurrency{std::move(concurrency)}
 { }
 
 bool attributes::is_timestamp_set() const {
@@ -53,10 +51,6 @@ bool attributes::is_service_level_set() const {
     return bool(_service_level);
 }
 
-bool attributes::is_concurrency_set() const {
-    return bool(_concurrency);
-}
-
 int64_t attributes::get_timestamp(int64_t now, const query_options& options) {
     if (!_timestamp.has_value() || _timestamp_unset_guard.is_unset(options)) {
         return now;
@@ -129,27 +123,6 @@ qos::service_level_options attributes::get_service_level(qos::service_level_cont
     return sl_controller.get_service_level(sl_name).slo;
 }
 
-std::optional<int32_t> attributes::get_concurrency(const query_options& options) const {
-    if (!_concurrency.has_value()) {
-        return std::nullopt;
-    }
-
-    cql3::raw_value concurrency_raw = expr::evaluate(*_concurrency, options);
-    if (concurrency_raw.is_null()) {
-        throw exceptions::invalid_request_exception("Invalid null value of concurrency");
-    }
-    int32_t concurrency;
-    try {
-        concurrency = concurrency_raw.view().validate_and_deserialize<int32_t>(*int32_type);
-    } catch (marshal_exception& e) {
-        throw exceptions::invalid_request_exception("Invalid concurrency value");
-    }
-    if (concurrency <= 0) {
-        throw exceptions::invalid_request_exception("Concurrency must be a positive integer");
-    }
-    return concurrency;
-}
-
 void attributes::fill_prepare_context(prepare_context& ctx) {
     if (_timestamp.has_value()) {
         expr::fill_prepare_context(*_timestamp, ctx);
@@ -160,13 +133,10 @@ void attributes::fill_prepare_context(prepare_context& ctx) {
     if (_timeout.has_value()) {
         expr::fill_prepare_context(*_timeout, ctx);
     }
-    if (_concurrency.has_value()) {
-        expr::fill_prepare_context(*_concurrency, ctx);
-    }
 }
 
 std::unique_ptr<attributes> attributes::raw::prepare(data_dictionary::database db, const sstring& ks_name, const sstring& cf_name) const {
-    std::optional<expr::expression> ts, ttl, to, conc;
+    std::optional<expr::expression> ts, ttl, to;
 
     if (timestamp.has_value()) {
         ts = prepare_expression(*timestamp, db, ks_name, nullptr, timestamp_receiver(ks_name, cf_name));
@@ -183,12 +153,7 @@ std::unique_ptr<attributes> attributes::raw::prepare(data_dictionary::database d
         verify_no_aggregate_functions(*timeout, "USING clause");
     }
 
-    if (concurrency.has_value()) {
-        conc = prepare_expression(*concurrency, db, ks_name, nullptr, concurrency_receiver(ks_name, cf_name));
-        verify_no_aggregate_functions(*concurrency, "USING clause");
-    }
-
-    return std::unique_ptr<attributes>{new attributes{std::move(ts), std::move(ttl), std::move(to), std::move(service_level), std::move(conc)}};
+    return std::unique_ptr<attributes>{new attributes{std::move(ts), std::move(ttl), std::move(to), std::move(service_level)}};
 }
 
 lw_shared_ptr<column_specification> attributes::raw::timestamp_receiver(const sstring& ks_name, const sstring& cf_name) const {
@@ -203,8 +168,4 @@ lw_shared_ptr<column_specification> attributes::raw::timeout_receiver(const sstr
     return make_lw_shared<column_specification>(ks_name, cf_name, ::make_shared<column_identifier>("[timeout]", true), duration_type);
 }
 
-lw_shared_ptr<column_specification> attributes::raw::concurrency_receiver(const sstring& ks_name, const sstring& cf_name) const {
-    return make_lw_shared<column_specification>(ks_name, cf_name, ::make_shared<column_identifier>("[concurrency]", true), data_type_for<int32_t>());
-}
-
 }

cql3/attributes.hh

@@ -36,15 +36,13 @@ private:
     std::optional<cql3::expr::expression> _time_to_live;
     std::optional<cql3::expr::expression> _timeout;
     std::optional<sstring> _service_level;
-    std::optional<cql3::expr::expression> _concurrency;
 public:
     static std::unique_ptr<attributes> none();
 private:
     attributes(std::optional<cql3::expr::expression>&& timestamp,
                std::optional<cql3::expr::expression>&& time_to_live,
                std::optional<cql3::expr::expression>&& timeout,
-               std::optional<sstring> service_level,
-               std::optional<cql3::expr::expression>&& concurrency);
+               std::optional<sstring> service_level);
 public:
     bool is_timestamp_set() const;
 
@@ -54,8 +52,6 @@ public:
 
     bool is_service_level_set() const;
 
-    bool is_concurrency_set() const;
-
     int64_t get_timestamp(int64_t now, const query_options& options);
 
     std::optional<int32_t> get_time_to_live(const query_options& options);
@@ -64,8 +60,6 @@ public:
 
     qos::service_level_options get_service_level(qos::service_level_controller& sl_controller) const;
 
-    std::optional<int32_t> get_concurrency(const query_options& options) const;
-
     void fill_prepare_context(prepare_context& ctx);
 
     class raw final {
@@ -74,7 +68,6 @@ public:
         std::optional<cql3::expr::expression> time_to_live;
         std::optional<cql3::expr::expression> timeout;
         std::optional<sstring> service_level;
-        std::optional<cql3::expr::expression> concurrency;
 
         std::unique_ptr<attributes> prepare(data_dictionary::database db, const sstring& ks_name, const sstring& cf_name) const;
     private:
@@ -83,8 +76,6 @@ public:
         lw_shared_ptr<column_specification> time_to_live_receiver(const sstring& ks_name, const sstring& cf_name) const;
 
         lw_shared_ptr<column_specification> timeout_receiver(const sstring& ks_name, const sstring& cf_name) const;
-
-        lw_shared_ptr<column_specification> concurrency_receiver(const sstring& ks_name, const sstring& cf_name) const;
     };
 };
 

cql3/statements/alter_service_level_statement.cc

@@ -37,12 +37,6 @@ future<::shared_ptr<cql_transport::messages::result_message>>
 alter_service_level_statement::execute(query_processor& qp,
         service::query_state &state,
         const query_options &, std::optional<service::group0_guard> guard) const {
-    if (_service_level == qos::service_level_controller::default_service_level_name) {
-        sstring reason = seastar::format("The default service level, {}, cannot be altered",
-                qos::service_level_controller::default_service_level_name);
-        throw exceptions::invalid_request_exception(std::move(reason));
-    }
-
     service::group0_batch mc{std::move(guard)};
     validate_shares_option(qp, _slo);
     qos::service_level& sl = state.get_service_level_controller().get_service_level(_service_level);

cql3/statements/alter_table_statement.cc

@@ -422,14 +422,7 @@ std::pair<schema_ptr, std::vector<view_ptr>> alter_table_statement::prepare_sche
                 throw exceptions::invalid_request_exception(format("The synchronous_updates option is only applicable to materialized views, not to base tables"));
             }
 
-            if (is_cdc_log_table) {
-                auto gc_opts = _properties->get_tombstone_gc_options(schema_extensions);
-                if (gc_opts && gc_opts->mode() == tombstone_gc_mode::repair) {
-                    throw exceptions::invalid_request_exception("The 'repair' mode for tombstone_gc is not allowed on CDC log tables.");
-                }
-            }
-
-            _properties->apply_to_builder(cfm, std::move(schema_extensions), db, keyspace(), !is_cdc_log_table);
+            _properties->apply_to_builder(cfm, std::move(schema_extensions), db, keyspace());
         }
         break;
 

cql3/statements/alter_view_statement.cc

@@ -55,29 +55,8 @@ view_ptr alter_view_statement::prepare_view(data_dictionary::database db) const
     auto schema_extensions = _properties->make_schema_extensions(db.extensions());
     _properties->validate(db, keyspace(), schema_extensions);
 
-    bool is_colocated = [&] {
-        if (!db.find_keyspace(keyspace()).get_replication_strategy().uses_tablets()) {
-            return false;
-        }
-        auto base_schema = db.find_schema(schema->view_info()->base_id());
-        if (!base_schema) {
-            return false;
-        }
-        return std::ranges::equal(
-            schema->partition_key_columns(),
-            base_schema->partition_key_columns(),
-            [](const column_definition& a, const column_definition& b) { return a.name() == b.name(); });
-    }();
-
-    if (is_colocated) {
-        auto gc_opts = _properties->get_tombstone_gc_options(schema_extensions);
-        if (gc_opts && gc_opts->mode() == tombstone_gc_mode::repair) {
-            throw exceptions::invalid_request_exception("The 'repair' mode for tombstone_gc is not allowed on co-located materialized view tables.");
-        }
-    }
-
     auto builder = schema_builder(schema);
-    _properties->apply_to_builder(builder, std::move(schema_extensions), db, keyspace(), !is_colocated);
+    _properties->apply_to_builder(builder, std::move(schema_extensions), db, keyspace());
 
     if (builder.get_gc_grace_seconds() == 0) {
         throw exceptions::invalid_request_exception(

cql3/statements/attach_service_level_statement.cc

@@ -43,14 +43,6 @@ attach_service_level_statement::execute(query_processor& qp,
         service::query_state &state,
         const query_options &,
         std::optional<service::group0_guard> guard) const {
-    if (_service_level == qos::service_level_controller::default_service_level_name) {
-        sstring reason = seastar::format("The default service level, {}, cannot be "
-                "attached to a role. If you want to detach an attached service level, "
-                "use the DETACH SERVICE LEVEL statement",
-                qos::service_level_controller::default_service_level_name);
-        throw exceptions::invalid_request_exception(std::move(reason));
-    }
-
     auto sli = co_await state.get_service_level_controller().get_distributed_service_level(_service_level);
     if (sli.empty()) {
         throw qos::nonexistant_service_level_exception(_service_level);

cql3/statements/batch_statement.cc

@@ -331,7 +331,7 @@ future<shared_ptr<cql_transport::messages::result_message>> batch_statement::exe
     if (!cl_for_paxos) [[unlikely]] {
         return make_exception_future<shared_ptr<cql_transport::messages::result_message>>(std::move(cl_for_paxos).assume_error());
     }
-    std::unique_ptr<cas_request> request;
+    seastar::shared_ptr<cas_request> request;
     schema_ptr schema;
 
     db::timeout_clock::time_point now = db::timeout_clock::now();
@@ -354,9 +354,9 @@ future<shared_ptr<cql_transport::messages::result_message>> batch_statement::exe
         if (keys.empty()) {
             continue;
         }
-        if (!request) {
+        if (request.get() == nullptr) {
             schema = statement.s;
-            request = std::make_unique<cas_request>(schema, std::move(keys));
+            request = seastar::make_shared<cas_request>(schema, std::move(keys));
         } else if (keys.size() != 1 || keys.front().equal(request->key().front(), dht::ring_position_comparator(*schema)) == false) {
             throw exceptions::invalid_request_exception("BATCH with conditions cannot span multiple partitions");
         }
@@ -366,7 +366,7 @@ future<shared_ptr<cql_transport::messages::result_message>> batch_statement::exe
 
         request->add_row_update(statement, std::move(ranges), std::move(json_cache), statement_options);
     }
-    if (!request) {
+    if (request.get() == nullptr) {
         throw exceptions::invalid_request_exception(format("Unrestricted partition key in a conditional BATCH"));
     }
 
@@ -377,10 +377,9 @@ future<shared_ptr<cql_transport::messages::result_message>> batch_statement::exe
             );
     }
 
-    auto* request_ptr = request.get();
-    return qp.proxy().cas(schema, std::move(cas_shard), *request_ptr, request->read_command(qp), request->key(),
+    return qp.proxy().cas(schema, std::move(cas_shard), request, request->read_command(qp), request->key(),
             {read_timeout, qs.get_permit(), qs.get_client_state(), qs.get_trace_state()},
-            std::move(cl_for_paxos).assume_value(), cl_for_learn, batch_timeout, cas_timeout).then([this, request = std::move(request)] (bool is_applied) {
+            std::move(cl_for_paxos).assume_value(), cl_for_learn, batch_timeout, cas_timeout).then([this, request] (bool is_applied) {
         return request->build_cas_result_set(_metadata, _columns_of_cas_result_set, is_applied);
     });
 }

cql3/statements/cf_prop_defs.cc

@@ -293,7 +293,7 @@ std::optional<db::tablet_options::map_type> cf_prop_defs::get_tablet_options() c
     return std::nullopt;
 }
 
-void cf_prop_defs::apply_to_builder(schema_builder& builder, schema::extensions_map schema_extensions, const data_dictionary::database& db, sstring ks_name, bool supports_repair) const {
+void cf_prop_defs::apply_to_builder(schema_builder& builder, schema::extensions_map schema_extensions, const data_dictionary::database& db, sstring ks_name) const {
     if (has_property(KW_COMMENT)) {
         builder.set_comment(get_string(KW_COMMENT, ""));
     }
@@ -379,7 +379,7 @@ void cf_prop_defs::apply_to_builder(schema_builder& builder, schema::extensions_
     }
     // Set default tombstone_gc mode.
     if (!schema_extensions.contains(tombstone_gc_extension::NAME)) {
-        auto ext = seastar::make_shared<tombstone_gc_extension>(get_default_tombstone_gc_mode(db, ks_name, supports_repair));
+        auto ext = seastar::make_shared<tombstone_gc_extension>(get_default_tombstone_gc_mode(db, ks_name));
         schema_extensions.emplace(tombstone_gc_extension::NAME, std::move(ext));
     }
     builder.set_extensions(std::move(schema_extensions));

cql3/statements/cf_prop_defs.hh

@@ -110,7 +110,7 @@ public:
     bool get_synchronous_updates_flag() const;
     std::optional<db::tablet_options::map_type> get_tablet_options() const;
 
-    void apply_to_builder(schema_builder& builder, schema::extensions_map schema_extensions, const data_dictionary::database& db, sstring ks_name, bool supports_repair) const;
+    void apply_to_builder(schema_builder& builder, schema::extensions_map schema_extensions, const data_dictionary::database& db, sstring ks_name) const;
     void validate_minimum_int(const sstring& field, int32_t minimum_value, int32_t default_value) const;
 };
 

cql3/statements/create_index_statement.cc

@@ -201,14 +201,7 @@ view_ptr create_index_statement::create_view_for_index(const schema_ptr schema,
         "";
     builder.with_view_info(schema, false, where_clause);
 
-    bool is_colocated = [&] {
-        if (!db.find_keyspace(keyspace()).get_replication_strategy().uses_tablets()) {
-            return false;
-        }
-        return im.local();
-    }();
-
-    auto tombstone_gc_ext = seastar::make_shared<tombstone_gc_extension>(get_default_tombstone_gc_mode(db, schema->ks_name(), !is_colocated));
+    auto tombstone_gc_ext = seastar::make_shared<tombstone_gc_extension>(get_default_tombstone_gc_mode(db, schema->ks_name()));
     builder.add_extension(tombstone_gc_extension::NAME, std::move(tombstone_gc_ext));
 
     // A local secondary index should be backed by a *synchronous* view,
@@ -279,15 +272,11 @@ std::vector<::shared_ptr<index_target>> create_index_statement::validate_while_e
         throw exceptions::invalid_request_exception(format("index names shouldn't be more than {:d} characters long (got \"{}\")", schema::NAME_LENGTH, _index_name.c_str()));
     }
 
-    // Regular secondary indexes require rf-rack-validity.
-    // Custom indexes need to validate this property themselves, if they need it.
-    if (!_properties || !_properties->custom_class) {
-        try {
-            db::view::validate_view_keyspace(db, keyspace());
-        } catch (const std::exception& e) {
-            // The type of the thrown exception is not specified, so we need to wrap it here.
-            throw exceptions::invalid_request_exception(e.what());
-        }
+    try {
+        db::view::validate_view_keyspace(db, keyspace());
+    } catch (const std::exception& e) {
+        // The type of the thrown exception is not specified, so we need to wrap it here.
+        throw exceptions::invalid_request_exception(e.what());
     }
 
     validate_for_local_index(*schema);
@@ -303,7 +292,7 @@ std::vector<::shared_ptr<index_target>> create_index_statement::validate_while_e
             throw exceptions::invalid_request_exception(format("Non-supported custom class \'{}\' provided", *(_properties->custom_class)));
         }
         auto custom_index = (*custom_index_factory)();
-        custom_index->validate(*schema, *_properties, targets, db.features(), db);
+        custom_index->validate(*schema, *_properties, targets, db.features());
         _properties->index_version = custom_index->index_version(*schema);
     }
 

cql3/statements/create_service_level_statement.cc

@@ -45,12 +45,6 @@ create_service_level_statement::execute(query_processor& qp,
         throw exceptions::invalid_request_exception("Names starting with '$' are reserved for internal tenants. Use a different name.");
     }
 
-    if (_service_level == qos::service_level_controller::default_service_level_name) {
-        sstring reason = seastar::format("The default service level, {}, already exists "
-                "and cannot be created", qos::service_level_controller::default_service_level_name);
-        throw exceptions::invalid_request_exception(std::move(reason));
-    }
-
     service::group0_batch mc{std::move(guard)};
     validate_shares_option(qp, _slo);
     

cql3/statements/create_table_statement.cc

@@ -128,7 +128,7 @@ void create_table_statement::apply_properties_to(schema_builder& builder, const
         builder.set_compressor_params(db.get_config().sstable_compression_user_table_options());
     }
 
-    _properties->apply_to_builder(builder, _properties->make_schema_extensions(db.extensions()), db, keyspace(), true);
+    _properties->apply_to_builder(builder, _properties->make_schema_extensions(db.extensions()), db, keyspace());
 }
 
 void create_table_statement::add_column_metadata_from_aliases(schema_builder& builder, std::vector<bytes> aliases, const std::vector<data_type>& types, column_kind kind) const

cql3/statements/create_view_statement.cc

@@ -373,30 +373,7 @@ std::pair<view_ptr, cql3::cql_warnings_vec> create_view_statement::prepare_view(
             db::view::create_virtual_column(builder, def->name(), def->type);
         }
     }
-
-    bool is_colocated = [&] {
-        if (!db.find_keyspace(keyspace()).get_replication_strategy().uses_tablets()) {
-            return false;
-        }
-        if (target_partition_keys.size() != schema->partition_key_columns().size()) {
-            return false;
-        }
-        for (size_t i = 0; i < target_partition_keys.size(); ++i) {
-            if (target_partition_keys[i] != &schema->partition_key_columns()[i]) {
-                return false;
-            }
-        }
-        return true;
-    }();
-
-    if (is_colocated) {
-        auto gc_opts = _properties.properties()->get_tombstone_gc_options(schema_extensions);
-        if (gc_opts && gc_opts->mode() == tombstone_gc_mode::repair) {
-            throw exceptions::invalid_request_exception("The 'repair' mode for tombstone_gc is not allowed on co-located materialized view tables.");
-        }
-    }
-
-    _properties.properties()->apply_to_builder(builder, std::move(schema_extensions), db, keyspace(), !is_colocated);
+    _properties.properties()->apply_to_builder(builder, std::move(schema_extensions), db, keyspace());
 
     if (builder.default_time_to_live().count() > 0) {
         throw exceptions::invalid_request_exception(

cql3/statements/drop_service_level_statement.cc

@@ -34,11 +34,6 @@ drop_service_level_statement::execute(query_processor& qp,
         service::query_state &state,
         const query_options &,
         std::optional<service::group0_guard> guard) const {
-    if (_service_level == qos::service_level_controller::default_service_level_name) {
-        sstring reason = seastar::format("The default service level, {}, cannot be dropped",
-                qos::service_level_controller::default_service_level_name);
-        throw exceptions::invalid_request_exception(std::move(reason));
-    }
     service::group0_batch mc{std::move(guard)};
     auto& sl = state.get_service_level_controller();
     co_await sl.drop_distributed_service_level(_service_level, _if_exists, mc);

cql3/statements/ks_prop_defs.cc

@@ -8,7 +8,6 @@
  * SPDX-License-Identifier: (LicenseRef-ScyllaDB-Source-Available-1.0 and Apache-2.0)
  */
 
-#include "seastar/core/format.hh"
 #include "seastar/core/sstring.hh"
 #include "utils/assert.hh"
 #include "cql3/statements/ks_prop_defs.hh"
@@ -114,17 +113,6 @@ static locator::replication_strategy_config_options prepare_options(
         return options;
     }
 
-    if (uses_tablets) {
-        for (const auto& opt: old_options) {
-            if (opt.first == ks_prop_defs::REPLICATION_FACTOR_KEY) {
-                on_internal_error(logger, format("prepare_options: old_options contains invalid key '{}'", ks_prop_defs::REPLICATION_FACTOR_KEY));
-            }
-            if (!options.contains(opt.first)) {
-                throw exceptions::configuration_exception(fmt::format("Attempted to implicitly drop replicas in datacenter {}. If this is the desired behavior, set replication factor to 0 in {} explicitly.", opt.first, opt.first));
-            }
-        }
-    }
-
     // For users' convenience, expand the 'replication_factor' option into a replication factor for each DC.
     // If the user simply switches from another strategy without providing any options,
     // but the other strategy used the 'replication_factor' option, it will also be expanded.

cql3/statements/modification_statement.cc

@@ -401,8 +401,7 @@ modification_statement::execute_with_condition(query_processor& qp, service::que
                     type.is_update() ? "update" : "deletion"));
     }
 
-    auto request = std::make_unique<cas_request>(s, std::move(keys));
-    auto* request_ptr = request.get();
+    auto request = seastar::make_shared<cas_request>(s, std::move(keys));
     // cas_request can be used for batches as well single statements; Here we have just a single
     // modification in the list of CAS commands, since we're handling single-statement execution.
     request->add_row_update(*this, std::move(ranges), std::move(json_cache), options);
@@ -428,9 +427,9 @@ modification_statement::execute_with_condition(query_processor& qp, service::que
         tablet_info = erm->check_locality(token);
     }
 
-    return qp.proxy().cas(s, std::move(cas_shard), *request_ptr, request->read_command(qp), request->key(),
+    return qp.proxy().cas(s, std::move(cas_shard), request, request->read_command(qp), request->key(),
             {read_timeout, qs.get_permit(), qs.get_client_state(), qs.get_trace_state()},
-            std::move(cl_for_paxos).assume_value(), cl_for_learn, statement_timeout, cas_timeout).then([this, request = std::move(request), tablet_replicas = std::move(tablet_info->tablet_replicas), token_range = tablet_info->token_range] (bool is_applied) {
+            std::move(cl_for_paxos).assume_value(), cl_for_learn, statement_timeout, cas_timeout).then([this, request, tablet_replicas = std::move(tablet_info->tablet_replicas), token_range = tablet_info->token_range] (bool is_applied) {
         auto result = request->build_cas_result_set(_metadata, _columns_of_cas_result_set, is_applied);
         result->add_tablet_info(tablet_replicas, token_range);
         return result;

cql3/statements/prune_materialized_view_statement.cc

@@ -21,7 +21,7 @@ namespace cql3 {
 namespace statements {
 
 static future<> delete_ghost_rows(dht::partition_range_vector partition_ranges, std::vector<query::clustering_range> clustering_bounds, view_ptr view,
-        service::storage_proxy& proxy, service::query_state& state, const query_options& options, cql_stats& stats, db::timeout_clock::duration timeout_duration, size_t concurrency) {
+        service::storage_proxy& proxy, service::query_state& state, const query_options& options, cql_stats& stats, db::timeout_clock::duration timeout_duration) {
     auto key_columns = std::ranges::to<std::vector<const column_definition*>>(
         view->all_columns()
         | std::views::filter([] (const column_definition& cdef) { return cdef.is_primary_key(); })
@@ -35,7 +35,7 @@ static future<> delete_ghost_rows(dht::partition_range_vector partition_ranges,
     tracing::trace(state.get_trace_state(), "Deleting ghost rows from partition ranges {}", partition_ranges);
 
     auto p = service::pager::query_pagers::ghost_row_deleting_pager(schema_ptr(view), selection, state,
-            options, std::move(command), std::move(partition_ranges), stats, proxy, timeout_duration, concurrency);
+            options, std::move(command), std::move(partition_ranges), stats, proxy, timeout_duration);
 
     int32_t page_size = std::max(options.get_page_size(), 1000);
     auto now = gc_clock::now();
@@ -62,8 +62,7 @@ future<::shared_ptr<cql_transport::messages::result_message>> prune_materialized
     auto timeout_duration = get_timeout(state.get_client_state(), options);
     dht::partition_range_vector key_ranges = _restrictions->get_partition_key_ranges(options);
     std::vector<query::clustering_range> clustering_bounds = _restrictions->get_clustering_bounds(options);
-    size_t concurrency = _attrs->is_concurrency_set() ? _attrs->get_concurrency(options).value() : 1;
-    return delete_ghost_rows(std::move(key_ranges), std::move(clustering_bounds), view_ptr(_schema), qp.proxy(), state, options, _stats, timeout_duration, concurrency).then([] {
+    return delete_ghost_rows(std::move(key_ranges), std::move(clustering_bounds), view_ptr(_schema), qp.proxy(), state, options, _stats, timeout_duration).then([] {
         return make_ready_future<::shared_ptr<cql_transport::messages::result_message>>(::make_shared<cql_transport::messages::result_message::void_message>());
     });
 }

cql3/statements/select_statement.cc

@@ -2031,16 +2031,14 @@ future<shared_ptr<cql_transport::messages::result_message>> vector_indexed_table
                     fmt::format("Use of ANN OF in an ORDER BY clause requires a LIMIT that is not greater than {}. LIMIT was {}", max_ann_query_limit, limit)));
         }
 
-        auto timeout = db::timeout_clock::now() + get_timeout(state.get_client_state(), options);
-        auto aoe = abort_on_expiry(timeout);
-        auto pkeys = co_await qp.vector_store_client().ann(
-                _schema->ks_name(), _index.metadata().name(), _schema, get_ann_ordering_vector(options), limit, aoe.abort_source());
+        auto as = abort_source();
+        auto pkeys = co_await qp.vector_store_client().ann(_schema->ks_name(), _index.metadata().name(), _schema, get_ann_ordering_vector(options), limit, as);
         if (!pkeys.has_value()) {
             co_await coroutine::return_exception(
                     exceptions::invalid_request_exception(std::visit(vector_search::vector_store_client::ann_error_visitor{}, pkeys.error())));
         }
 
-        co_return co_await query_base_table(qp, state, options, pkeys.value(), timeout);
+        co_return co_await query_base_table(qp, state, options, pkeys.value());
     });
 
     auto page_size = options.get_page_size();
@@ -2075,10 +2073,10 @@ std::vector<float> vector_indexed_table_select_statement::get_ann_ordering_vecto
     return util::to_vector<float>(values);
 }
 
-future<::shared_ptr<cql_transport::messages::result_message>> vector_indexed_table_select_statement::query_base_table(query_processor& qp,
-        service::query_state& state, const query_options& options, const std::vector<vector_search::primary_key>& pkeys,
-        lowres_clock::time_point timeout) const {
+future<::shared_ptr<cql_transport::messages::result_message>> vector_indexed_table_select_statement::query_base_table(
+        query_processor& qp, service::query_state& state, const query_options& options, const std::vector<vector_search::primary_key>& pkeys) const {
     auto command = prepare_command_for_base_query(qp, state, options);
+    auto timeout = db::timeout_clock::now() + get_timeout(state.get_client_state(), options);
 
     // For tables without clustering columns, we can optimize by querying
     // partition ranges instead of individual primary keys, since the

cql3/statements/select_statement.hh

@@ -389,8 +389,8 @@ private:
 
     std::vector<float> get_ann_ordering_vector(const query_options& options) const;
 
-    future<::shared_ptr<cql_transport::messages::result_message>> query_base_table(query_processor& qp, service::query_state& state,
-            const query_options& options, const std::vector<vector_search::primary_key>& pkeys, lowres_clock::time_point timeout) const;
+    future<::shared_ptr<cql_transport::messages::result_message>> query_base_table(
+            query_processor& qp, service::query_state& state, const query_options& options, const std::vector<vector_search::primary_key>& pkeys) const;
 
     future<::shared_ptr<cql_transport::messages::result_message>> query_base_table(query_processor& qp, service::query_state& state,
             const query_options& options, lw_shared_ptr<query::read_command> command, lowres_clock::time_point timeout,

data_dictionary/CMakeLists.txt

@@ -12,8 +12,5 @@ target_link_libraries(data_dictionary
     Seastar::seastar
     xxHash::xxhash)
 
-if (Scylla_USE_PRECOMPILED_HEADER_USE)
-  target_precompile_headers(data_dictionary REUSE_FROM scylla-precompiled-header)
-endif()
 check_headers(check-headers data_dictionary
   GLOB_RECURSE ${CMAKE_CURRENT_SOURCE_DIR}/*.hh)

db/CMakeLists.txt

@@ -10,6 +10,7 @@ target_sources(db
     schema_applier.cc
     schema_tables.cc
     cql_type_parser.cc
+    legacy_schema_migrator.cc
     commitlog/commitlog.cc
     commitlog/commitlog_replayer.cc
     commitlog/commitlog_entry.cc
@@ -59,8 +60,5 @@ target_link_libraries(db
     data_dictionary
     cql3)
 
-if (Scylla_USE_PRECOMPILED_HEADER_USE)
-  target_precompile_headers(db REUSE_FROM scylla-precompiled-header)
-endif()
 check_headers(check-headers db
   GLOB_RECURSE ${CMAKE_CURRENT_SOURCE_DIR}/*.hh)

db/commitlog/commitlog.cc

@@ -3461,15 +3461,12 @@ db::commitlog::read_log_file(const replay_state& state, sstring filename, sstrin
             clogger.debug("Read {} bytes of data ({}, {})", size, pos, rem);
 
             while (rem < size) {
-                const auto initial_size = initial.size_bytes();
-
                 if (eof) {
-                    auto reason = fmt::format("unexpected EOF, pos={}, rem={}, size={}, alignment={}, initial_size={}",
-                            pos, rem, size, alignment, initial_size);
+                    auto reason = fmt::format("unexpected EOF, rem={}, size={}", rem, size);
                     throw segment_truncation(std::move(reason), block_boundry);
                 }
 
-                auto block_size = alignment - initial_size;
+                auto block_size = alignment - initial.size_bytes();
                 // using a stream is perhaps not 100% effective, but we need to 
                 // potentially address data in pages smaller than the current 
                 // disk/fs we are reading from can handle (but please no). 
@@ -3477,9 +3474,8 @@ db::commitlog::read_log_file(const replay_state& state, sstring filename, sstrin
 
                 if (tmp.size_bytes() == 0) {
                     eof = true;
-                    auto reason = fmt::format("read 0 bytes, while tried to read {} bytes. "
-                            "pos={}, rem={}, size={}, alignment={}, initial_size={}",
-                            block_size, pos, rem, size, alignment, initial_size);
+                    auto reason = fmt::format("read 0 bytes, while tried to read {} bytes. rem={}, size={}",
+                            block_size, rem, size);
                     throw segment_truncation(std::move(reason), block_boundry);
                 }
 
@@ -3515,13 +3511,13 @@ db::commitlog::read_log_file(const replay_state& state, sstring filename, sstrin
                     auto checksum = crc.checksum();
 
                     if (check != checksum) {
-                        auto reason = fmt::format("checksums do not match: {:x} vs. {:x}. pos={}, rem={}, size={}, alignment={}, initial_size={}",
-                                check, checksum, pos, rem, size, alignment, initial_size);
+                        auto reason = fmt::format("checksums do not match: {:x} vs. {:x}. rem={}, size={}",
+                                check, checksum, rem, size);
                         throw segment_data_corruption_error(std::move(reason), alignment);
                     }
                     if (id != this->id) {
-                        auto reason = fmt::format("IDs do not match: {} vs. {}. pos={}, rem={}, size={}, alignment={}, initial_size={}",
-                                id, this->id, pos, rem, size, alignment, initial_size);
+                        auto reason = fmt::format("IDs do not match: {} vs. {}. rem={}, size={}",
+                                id, this->id, rem, size);
                         throw segment_truncation(std::move(reason), pos + rem);
                     }
                 }
@@ -3630,10 +3626,6 @@ db::commitlog::read_log_file(const replay_state& state, sstring filename, sstrin
             auto old = pos;
             pos = next_pos(off);
             clogger.trace("Pos {} -> {} ({})", old, pos, off);
-            // #24346 check eof status whenever we move file pos.
-            if (pos >= file_size) {
-                eof = true;
-            }
         }
 
         future<> read_entry() {

db/config.cc

@@ -36,7 +36,6 @@
 #include "sstables/compressor.hh"
 #include "utils/log.hh"
 #include "service/tablet_allocator_fwd.hh"
-#include "backlog_controller_fwd.hh"
 #include "utils/config_file_impl.hh"
 #include "exceptions/exceptions.hh"
 #include <seastar/core/metrics_api.hh>
@@ -631,8 +630,6 @@ db::config::config(std::shared_ptr<db::extensions> exts)
         "If set to higher than 0, ignore the controller's output and set the memtable shares statically. Do not set this unless you know what you are doing and suspect a problem in the controller. This option will be retired when the controller reaches more maturity.")
     , compaction_static_shares(this, "compaction_static_shares", liveness::LiveUpdate, value_status::Used, 0,
         "If set to higher than 0, ignore the controller's output and set the compaction shares statically. Do not set this unless you know what you are doing and suspect a problem in the controller. This option will be retired when the controller reaches more maturity.")
-    , compaction_max_shares(this, "compaction_max_shares", liveness::LiveUpdate, value_status::Used, default_compaction_maximum_shares,
-        "Set the maximum shares of regular compaction to the specific value. Do not set this unless you know what you are doing and suspect a problem in the controller. This option will be retired when the controller reaches more maturity.")
     , compaction_enforce_min_threshold(this, "compaction_enforce_min_threshold", liveness::LiveUpdate, value_status::Used, false,
         "If set to true, enforce the min_threshold option for compactions strictly. If false (default), Scylla may decide to compact even if below min_threshold.")
     , compaction_flush_all_tables_before_major_seconds(this, "compaction_flush_all_tables_before_major_seconds", value_status::Used, 86400,
@@ -1038,9 +1035,8 @@ db::config::config(std::shared_ptr<db::extensions> exts)
         "Controls whether traffic between nodes is compressed. The valid values are:\n"
         "* all: All traffic is compressed.\n"
         "* dc : Traffic between data centers is compressed.\n"
-        "* rack : Traffic between racks is compressed.\n"
         "* none : No compression.",
-        {"all", "dc", "rack", "none"})
+        {"all", "dc", "none"})
     , internode_compression_zstd_max_cpu_fraction(this, "internode_compression_zstd_max_cpu_fraction", liveness::LiveUpdate, value_status::Used, 0.000,
         "ZSTD compression of RPC will consume at most this fraction of each internode_compression_zstd_quota_refresh_period_ms time slice.\n"
         "If you wish to try out zstd for RPC compression, 0.05 is a reasonable starting point.")
@@ -1172,17 +1168,6 @@ db::config::config(std::shared_ptr<db::extensions> exts)
         "* default_weight: (Default: 1 **)  How many requests are handled during each turn of the RoundRobin.\n"
         "* weights: (Default: Keyspace: 1)  Takes a list of keyspaces. It sets how many requests are handled during each turn of the RoundRobin, based on the request_scheduler_id.")
     /**
-    * @Group Vector search settings
-    * @GroupDescription Settings for configuring and tuning vector search functionality.
-    */
-    , vector_store_primary_uri(this, "vector_store_primary_uri", liveness::LiveUpdate, value_status::Used, "",
-        "A comma-separated list of primary vector store node URIs. These nodes are preferred for vector search operations.")
-    , vector_store_secondary_uri(this, "vector_store_secondary_uri", liveness::LiveUpdate, value_status::Used, "",
-        "A comma-separated list of secondary vector store node URIs. These nodes are used as a fallback when all primary nodes are unavailable, and are typically located in a different availability zone for high availability.")
-    , vector_store_encryption_options(this, "vector_store_encryption_options", value_status::Used, {},
-        "Options for encrypted connections to the vector store. These options are used for HTTPS URIs in `vector_store_primary_uri` and `vector_store_secondary_uri`. The available options are:\n"
-        "* truststore: (Default: <not set, use system truststore>) Location of the truststore containing the trusted certificate for authenticating remote servers.")
-    /**
     * @Group Security properties
     * @GroupDescription Server and client security settings.
     */
@@ -1444,11 +1429,6 @@ db::config::config(std::shared_ptr<db::extensions> exts)
     , alternator_warn_authorization(this, "alternator_warn_authorization", liveness::LiveUpdate, value_status::Used, false, "Count and log warnings about failed authentication or authorization")
     , alternator_write_isolation(this, "alternator_write_isolation", value_status::Used, "", "Default write isolation policy for Alternator.")
     , alternator_streams_time_window_s(this, "alternator_streams_time_window_s", value_status::Used, 10, "CDC query confidence window for alternator streams.")
-    , alternator_streams_increased_compatibility(this, "alternator_streams_increased_compatibility", liveness::LiveUpdate, value_status::Used, false,
-        "Increases compatibility with DynamoDB Streams at the cost of performance. "
-        "If enabled, Alternator compares the existing item with the new one during "
-        "data-modifying operations to determine which event type should be emitted. "
-        "This penalty is incurred only for tables with Alternator Streams enabled.")
     , alternator_timeout_in_ms(this, "alternator_timeout_in_ms", liveness::LiveUpdate, value_status::Used, 10000,
         "The server-side timeout for completing Alternator API requests.")
     , alternator_ttl_period_in_seconds(this, "alternator_ttl_period_in_seconds", value_status::Used,
@@ -1470,6 +1450,7 @@ db::config::config(std::shared_ptr<db::extensions> exts)
     , alternator_max_expression_cache_entries_per_shard(this, "alternator_max_expression_cache_entries_per_shard", liveness::LiveUpdate, value_status::Used, 2000, "Maximum number of cached parsed request expressions, per shard.")
     , alternator_max_users_query_size_in_trace_output(this, "alternator_max_users_query_size_in_trace_output", liveness::LiveUpdate, value_status::Used, uint64_t(4096),
             "Maximum size of user's command in trace output (`alternator_op` entry). Larger traces will be truncated and have `<truncated>` message appended - which doesn't count to the maximum limit.")
+    , vector_store_primary_uri(this, "vector_store_primary_uri", liveness::LiveUpdate, value_status::Used, "", "A comma-separated list of vector store node URIs. If not set, vector search is disabled.")
     , abort_on_ebadf(this, "abort_on_ebadf", value_status::Used, true, "Abort the server on incorrect file descriptor access. Throws exception when disabled.")
     , sanitizer_report_backtrace(this, "sanitizer_report_backtrace", value_status::Used, false,
             "In debug mode, report log-structured allocator sanitizer violations with a backtrace. Slow.")

db/config.hh

@@ -189,7 +189,6 @@ public:
     named_value<bool> auto_adjust_flush_quota;
     named_value<float> memtable_flush_static_shares;
     named_value<float> compaction_static_shares;
-    named_value<float> compaction_max_shares;
     named_value<bool> compaction_enforce_min_threshold;
     named_value<uint32_t> compaction_flush_all_tables_before_major_seconds;
     named_value<sstring> cluster_name;
@@ -344,9 +343,6 @@ public:
     named_value<sstring> request_scheduler;
     named_value<sstring> request_scheduler_id;
     named_value<string_map> request_scheduler_options;
-    named_value<sstring> vector_store_primary_uri;
-    named_value<sstring> vector_store_secondary_uri;
-    named_value<string_map> vector_store_encryption_options;
     named_value<sstring> authenticator;
     named_value<sstring> internode_authenticator;
     named_value<sstring> authorizer;
@@ -465,7 +461,6 @@ public:
     named_value<bool> alternator_warn_authorization;
     named_value<sstring> alternator_write_isolation;
     named_value<uint32_t> alternator_streams_time_window_s;
-    named_value<bool> alternator_streams_increased_compatibility;
     named_value<uint32_t> alternator_timeout_in_ms;
     named_value<double> alternator_ttl_period_in_seconds;
     named_value<sstring> alternator_describe_endpoints;
@@ -474,6 +469,8 @@ public:
     named_value<uint32_t> alternator_max_expression_cache_entries_per_shard;
     named_value<uint64_t> alternator_max_users_query_size_in_trace_output;
 
+    named_value<sstring> vector_store_primary_uri;
+
     named_value<bool> abort_on_ebadf;
 
     named_value<bool> sanitizer_report_backtrace;

db/legacy_schema_migrator.cc

@@ -0,0 +1,602 @@
+/*
+ * Modified by ScyllaDB
+ * Copyright (C) 2017-present ScyllaDB
+ */
+
+/*
+ * SPDX-License-Identifier: (LicenseRef-ScyllaDB-Source-Available-1.0 and Apache-2.0)
+ */
+
+// Since Scylla 2.0, we use system tables whose schemas were introduced in
+// Cassandra 3. If Scylla boots to find a data directory with system tables
+// with older schemas - produced by pre-2.0 Scylla or by pre-3.0 Cassandra,
+// we need to migrate these old tables to the new format.
+//
+// We provide here a function, db::legacy_schema_migrator::migrate(),
+// for a one-time migration from old to new system tables. The function
+// reads old system tables, write them back in the new format, and finally
+// delete the old system tables. Scylla's main should call this function and
+// wait for the returned future, before starting to serve the database.
+
+#include <boost/iterator/filter_iterator.hpp>
+#include <seastar/core/future-util.hh>
+#include <seastar/util/log.hh>
+#include <map>
+#include <unordered_set>
+#include <chrono>
+
+#include "replica/database.hh"
+#include "legacy_schema_migrator.hh"
+#include "system_keyspace.hh"
+#include "schema_tables.hh"
+#include "schema/schema_builder.hh"
+#include "service/storage_proxy.hh"
+#include "utils/rjson.hh"
+#include "cql3/query_processor.hh"
+#include "cql3/untyped_result_set.hh"
+#include "cql3/util.hh"
+#include "cql3/statements/property_definitions.hh"
+
+static seastar::logger mlogger("legacy_schema_migrator");
+
+namespace db {
+namespace legacy_schema_migrator {
+
+// local data carriers
+
+class migrator {
+public:
+    static const std::unordered_set<sstring> legacy_schema_tables;
+
+    migrator(sharded<service::storage_proxy>& sp, sharded<replica::database>& db, sharded<db::system_keyspace>& sys_ks, cql3::query_processor& qp)
+                    : _sp(sp), _db(db), _sys_ks(sys_ks), _qp(qp) {
+    }
+    migrator(migrator&&) = default;
+
+    typedef db_clock::time_point time_point;
+
+    // TODO: we don't support triggers.
+    // this is a placeholder.
+    struct trigger {
+        time_point timestamp;
+        sstring name;
+        std::unordered_map<sstring, sstring> options;
+    };
+
+    struct table {
+        time_point timestamp;
+        schema_ptr metadata;
+        std::vector<trigger> triggers;
+    };
+
+    struct type {
+        time_point timestamp;
+        user_type metadata;
+    };
+
+    struct function {
+        time_point timestamp;
+        sstring ks_name;
+        sstring fn_name;
+        std::vector<sstring> arg_names;
+        std::vector<sstring> arg_types;
+        sstring return_type;
+        bool called_on_null_input;
+        sstring language;
+        sstring body;
+    };
+
+    struct aggregate {
+        time_point timestamp;
+        sstring ks_name;
+        sstring fn_name;
+        std::vector<sstring> arg_names;
+        std::vector<sstring> arg_types;
+        sstring return_type;
+        sstring final_func;
+        sstring initcond;
+        sstring state_func;
+        sstring state_type;
+    };
+
+    struct keyspace {
+        time_point timestamp;
+        sstring name;
+        bool durable_writes;
+        std::map<sstring, sstring> replication_params;
+
+        std::vector<table> tables;
+        std::vector<type> types;
+        std::vector<function> functions;
+        std::vector<aggregate> aggregates;
+    };
+
+    class unsupported_feature : public std::runtime_error {
+    public:
+        using runtime_error::runtime_error;
+    };
+
+    static sstring fmt_query(const char* fmt, const char* table) {
+        return fmt::format(fmt::runtime(fmt), db::system_keyspace::NAME, table);
+    }
+
+    typedef ::shared_ptr<cql3::untyped_result_set> result_set_type;
+    typedef const cql3::untyped_result_set::row row_type;
+
+    future<> read_table(keyspace& dst, sstring cf_name, time_point timestamp) {
+        auto fmt = "SELECT * FROM {}.{} WHERE keyspace_name = ? AND columnfamily_name = ?";
+        auto tq = fmt_query(fmt, db::system_keyspace::legacy::COLUMNFAMILIES);
+        auto cq = fmt_query(fmt, db::system_keyspace::legacy::COLUMNS);
+        auto zq = fmt_query(fmt, db::system_keyspace::legacy::TRIGGERS);
+
+        typedef std::tuple<future<result_set_type>, future<result_set_type>, future<result_set_type>, future<db::schema_tables::legacy::schema_mutations>> result_tuple;
+
+        return when_all(_qp.execute_internal(tq, { dst.name, cf_name }, cql3::query_processor::cache_internal::yes),
+                        _qp.execute_internal(cq, { dst.name, cf_name }, cql3::query_processor::cache_internal::yes),
+                        _qp.execute_internal(zq, { dst.name, cf_name }, cql3::query_processor::cache_internal::yes),
+                        db::schema_tables::legacy::read_table_mutations(_sp, dst.name, cf_name, db::system_keyspace::legacy::column_families()))
+                    .then([&dst, cf_name, timestamp](result_tuple&& t) {
+
+            result_set_type tables = std::get<0>(t).get();
+            result_set_type columns = std::get<1>(t).get();
+            result_set_type triggers = std::get<2>(t).get();
+            db::schema_tables::legacy::schema_mutations sm = std::get<3>(t).get();
+
+            row_type& td = tables->one();
+
+            auto ks_name = td.get_as<sstring>("keyspace_name");
+            auto cf_name = td.get_as<sstring>("columnfamily_name");
+            auto id = table_id(td.get_or("cf_id", generate_legacy_id(ks_name, cf_name).uuid()));
+
+            schema_builder builder(dst.name, cf_name, id);
+
+            builder.with_version(sm.digest());
+
+            cf_type cf = sstring_to_cf_type(td.get_or("type", sstring("standard")));
+            if (cf == cf_type::super) {
+                fail(unimplemented::cause::SUPER);
+            }
+
+            auto comparator = td.get_as<sstring>("comparator");
+            bool is_compound = cell_comparator::check_compound(comparator);
+            builder.set_is_compound(is_compound);
+            cell_comparator::read_collections(builder, comparator);
+
+            bool filter_sparse = false;
+
+            data_type default_validator = {};
+            if (td.has("default_validator")) {
+                default_validator = db::schema_tables::parse_type(td.get_as<sstring>("default_validator"));
+                if (default_validator->is_counter()) {
+                    builder.set_is_counter(true);
+                }
+                builder.set_default_validation_class(default_validator);
+            }
+
+            /*
+             * Determine whether or not the table is *really* dense
+             * We cannot trust is_dense value of true (see CASSANDRA-11502, that fixed the issue for 2.2 only, and not retroactively),
+             * but we can trust is_dense value of false.
+             */
+            auto is_dense = td.get_opt<bool>("is_dense");
+            if (!is_dense || *is_dense) {
+                is_dense = [&] {
+                    /*
+                     * As said above, this method is only here because we need to deal with thrift upgrades.
+                     * Once a CF has been "upgraded", i.e. we've rebuilt and save its CQL3 metadata at least once,
+                     * then we'll have saved the "is_dense" value and will be good to go.
+                     *
+                     * But non-upgraded thrift CF (and pre-7744 CF) will have no value for "is_dense", so we need
+                     * to infer that information without relying on it in that case. And for the most part this is
+                     * easy, a CF that has at least one REGULAR definition is not dense. But the subtlety is that not
+                     * having a REGULAR definition may not mean dense because of CQL3 definitions that have only the
+                     * PRIMARY KEY defined.
+                     *
+                     * So we need to recognize those special case CQL3 table with only a primary key. If we have some
+                     * clustering columns, we're fine as said above. So the only problem is that we cannot decide for
+                     * sure if a CF without REGULAR columns nor CLUSTERING_COLUMN definition is meant to be dense, or if it
+                     * has been created in CQL3 by say:
+                     *    CREATE TABLE test (k int PRIMARY KEY)
+                     * in which case it should not be dense. However, we can limit our margin of error by assuming we are
+                     * in the latter case only if the comparator is exactly CompositeType(UTF8Type).
+                     */
+                    std::optional<column_id> max_cl_idx;
+                    const cql3::untyped_result_set::row * regular = nullptr;
+                    for (auto& row : *columns) {
+                        auto kind_str = row.get_as<sstring>("type");
+                        if (kind_str == "compact_value") {
+                            continue;
+                        }
+
+                        auto kind = db::schema_tables::deserialize_kind(kind_str);
+
+                        if (kind == column_kind::regular_column) {
+                            if (regular != nullptr) {
+                                return false;
+                            }
+                            regular = &row;
+                            continue;
+                        }
+                        if (kind == column_kind::clustering_key) {
+                            max_cl_idx = std::max(column_id(row.get_or("component_index", 0)), max_cl_idx.value_or(column_id()));
+                        }
+                    }
+
+                    auto is_cql3_only_pk_comparator = [](const sstring& comparator) {
+                        if (!cell_comparator::check_compound(comparator)) {
+                            return false;
+                        }
+                        // CMH. We don't have composites, nor a parser for it. This is a simple way of c
+                        // checking the same.
+                        auto comma = comparator.find(',');
+                        if (comma != sstring::npos) {
+                            return false;
+                        }
+                        auto off = comparator.find('(');
+                        auto end = comparator.find(')');
+
+                        return comparator.compare(off, end - off, utf8_type->name()) == 0;
+                    };
+
+                    if (max_cl_idx) {
+                        auto n = std::count(comparator.begin(), comparator.end(), ','); // num comp - 1
+                        return *max_cl_idx == n;
+                    }
+
+                    if (regular) {
+                        return false;
+                    }
+
+                    return !is_cql3_only_pk_comparator(comparator);
+
+                }();
+
+                // now, if switched to sparse, remove redundant compact_value column and the last clustering column,
+                // directly copying CASSANDRA-11502 logic. See CASSANDRA-11315.
+
+                filter_sparse = !*is_dense;
+            }
+            builder.set_is_dense(*is_dense);
+
+            auto is_cql = !*is_dense && is_compound;
+            auto is_static_compact = !*is_dense && !is_compound;
+
+            // org.apache.cassandra.schema.LegacySchemaMigrator#isEmptyCompactValueColumn
+            auto is_empty_compact_value = [](const cql3::untyped_result_set::row& column_row) {
+                auto kind_str = column_row.get_as<sstring>("type");
+                // Cassandra only checks for "compact_value", but Scylla generates "regular" instead (#2586)
+                return (kind_str == "compact_value" || kind_str == "regular")
+                       && column_row.get_as<sstring>("column_name").empty();
+            };
+
+            for (auto& row : *columns) {
+                auto kind_str = row.get_as<sstring>("type");
+                auto kind = db::schema_tables::deserialize_kind(kind_str);
+                auto component_index = kind > column_kind::clustering_key ? 0 : column_id(row.get_or("component_index", 0));
+                auto name = row.get_or<sstring>("column_name", sstring());
+                auto validator = db::schema_tables::parse_type(row.get_as<sstring>("validator"));
+
+                if (is_empty_compact_value(row)) {
+                    continue;
+                }
+
+                if (filter_sparse) {
+                    if (kind_str == "compact_value") {
+                        continue;
+                    }
+                    if (kind == column_kind::clustering_key) {
+                        if (cf == cf_type::super && component_index != 0) {
+                            continue;
+                        }
+                        if (cf != cf_type::super && !is_compound) {
+                            continue;
+                        }
+                    }
+                }
+
+                std::optional<index_metadata_kind> index_kind;
+                sstring index_name;
+                index_options_map options;
+                if (row.has("index_type")) {
+                    index_kind = schema_tables::deserialize_index_kind(row.get_as<sstring>("index_type"));
+                }
+                if (row.has("index_name")) {
+                    index_name = row.get_as<sstring>("index_name");
+                }
+                if (row.has("index_options")) {
+                    sstring index_options_str = row.get_as<sstring>("index_options");
+                    options = rjson::parse_to_map<index_options_map>(std::string_view(index_options_str));
+                    sstring type;
+                    auto i = options.find("index_keys");
+                    if (i != options.end()) {
+                        options.erase(i);
+                        type = "KEYS";
+                    }
+                    i = options.find("index_keys_and_values");
+                    if (i != options.end()) {
+                        options.erase(i);
+                        type = "KEYS_AND_VALUES";
+                    }
+                    if (type.empty()) {
+                        if (validator->is_collection() && validator->is_multi_cell()) {
+                            type = "FULL";
+                        } else {
+                            type = "VALUES";
+                        }
+                    }
+                    auto column = cql3::util::maybe_quote(name);
+                    options["target"] = validator->is_collection()
+                                    ? type + "(" + column + ")"
+                                    : column;
+                }
+                if (index_kind) {
+                    // Origin assumes index_name is always set, so let's do the same
+                    builder.with_index(index_metadata(index_name, options, *index_kind, index_metadata::is_local_index::no));
+                }
+
+                data_type column_name_type = [&] {
+                    if (is_static_compact && kind == column_kind::regular_column) {
+                        return db::schema_tables::parse_type(comparator);
+                    }
+                    return utf8_type;
+                }();
+                auto column_name = [&] {
+                    try {
+                        return column_name_type->from_string(name);
+                    } catch (marshal_exception&) {
+                        // #2597: Scylla < 2.0 writes names in serialized form, try to recover
+                        column_name_type->validate(to_bytes_view(name));
+                        return to_bytes(name);
+                    }
+                }();
+                builder.with_column_ordered(column_definition(std::move(column_name), std::move(validator), kind, component_index));
+            }
+
+            if (is_static_compact) {
+                builder.set_regular_column_name_type(db::schema_tables::parse_type(comparator));
+            }
+
+            if (td.has("gc_grace_seconds")) {
+                builder.set_gc_grace_seconds(td.get_as<int32_t>("gc_grace_seconds"));
+            }
+            if (td.has("min_compaction_threshold")) {
+                builder.set_min_compaction_threshold(td.get_as<int32_t>("min_compaction_threshold"));
+            }
+            if (td.has("max_compaction_threshold")) {
+                builder.set_max_compaction_threshold(td.get_as<int32_t>("max_compaction_threshold"));
+            }
+            if (td.has("comment")) {
+                builder.set_comment(td.get_as<sstring>("comment"));
+            }
+            if (td.has("memtable_flush_period_in_ms")) {
+                builder.set_memtable_flush_period(td.get_as<int32_t>("memtable_flush_period_in_ms"));
+            }
+            if (td.has("caching")) {
+                builder.set_caching_options(caching_options::from_sstring(td.get_as<sstring>("caching")));
+            }
+            if (td.has("default_time_to_live")) {
+                builder.set_default_time_to_live(gc_clock::duration(td.get_as<int32_t>("default_time_to_live")));
+            }
+            if (td.has("speculative_retry")) {
+                builder.set_speculative_retry(td.get_as<sstring>("speculative_retry"));
+            }
+            if (td.has("compaction_strategy_class")) {
+                auto strategy = td.get_as<sstring>("compaction_strategy_class");
+                try {
+                    builder.set_compaction_strategy(compaction::compaction_strategy::type(strategy));
+                } catch (const exceptions::configuration_exception& e) {
+                    // If compaction strategy class isn't supported, fallback to incremental.
+                    mlogger.warn("Falling back to incremental compaction strategy after the problem: {}", e.what());
+                    builder.set_compaction_strategy(compaction::compaction_strategy_type::incremental);
+                }
+            }
+            if (td.has("compaction_strategy_options")) {
+                sstring strategy_options_str = td.get_as<sstring>("compaction_strategy_options");
+                builder.set_compaction_strategy_options(rjson::parse_to_map<std::map<sstring, sstring>>(std::string_view(strategy_options_str)));
+            }
+            auto comp_param = td.get_as<sstring>("compression_parameters");
+            compression_parameters cp(rjson::parse_to_map<std::map<sstring, sstring>>(std::string_view(comp_param)));
+            builder.set_compressor_params(cp);
+
+            if (td.has("min_index_interval")) {
+                builder.set_min_index_interval(td.get_as<int32_t>("min_index_interval"));
+            } else if (td.has("index_interval")) { // compatibility
+                builder.set_min_index_interval(td.get_as<int32_t>("index_interval"));
+            }
+            if (td.has("max_index_interval")) {
+                builder.set_max_index_interval(td.get_as<int32_t>("max_index_interval"));
+            }
+            if (td.has("bloom_filter_fp_chance")) {
+                builder.set_bloom_filter_fp_chance(td.get_as<double>("bloom_filter_fp_chance"));
+            } else {
+                builder.set_bloom_filter_fp_chance(builder.get_bloom_filter_fp_chance());
+            }
+            if (td.has("dropped_columns")) {
+                auto map = td.get_map<sstring, int64_t>("dropped_columns");
+                for (auto&& e : map) {
+                    builder.without_column(e.first, api::timestamp_type(e.second));
+                };
+            }
+
+            // ignore version. we're transient
+            if (!triggers->empty()) {
+                throw unsupported_feature("triggers");
+            }
+
+            dst.tables.emplace_back(table{timestamp, builder.build() });
+        });
+    }
+
+    future<> read_tables(keyspace& dst) {
+        auto query = fmt_query("SELECT columnfamily_name, writeTime(type) AS timestamp FROM {}.{} WHERE keyspace_name = ?",
+                        db::system_keyspace::legacy::COLUMNFAMILIES);
+        return _qp.execute_internal(query, {dst.name}, cql3::query_processor::cache_internal::yes).then([this, &dst](result_set_type result) {
+            return parallel_for_each(*result, [this, &dst](row_type& row) {
+                return read_table(dst, row.get_as<sstring>("columnfamily_name"), row.get_as<time_point>("timestamp"));
+            }).finally([result] {});
+        });
+    }
+
+    future<time_point> read_type_timestamp(keyspace& dst, sstring type_name) {
+        // TODO: Unfortunately there is not a single REGULAR column in system.schema_usertypes, so annoyingly we cannot
+        // use the writeTime() CQL function, and must resort to a lower level.
+        // Origin digs up the actual cells of target partition and gets timestamp from there.
+        // We should do the same, but g-dam that's messy. Lets give back dung value for now.
+        return make_ready_future<time_point>(dst.timestamp);
+    }
+
+    future<> read_types(keyspace& dst) {
+        auto query = fmt_query("SELECT * FROM {}.{} WHERE keyspace_name = ?", db::system_keyspace::legacy::USERTYPES);
+        return _qp.execute_internal(query, {dst.name}, cql3::query_processor::cache_internal::yes).then([this, &dst](result_set_type result) {
+            return parallel_for_each(*result, [this, &dst](row_type& row) {
+                auto name = row.get_blob_unfragmented("type_name");
+                auto columns = row.get_list<bytes>("field_names");
+                auto types = row.get_list<sstring>("field_types");
+                std::vector<data_type> field_types;
+                for (auto&& value : types) {
+                    field_types.emplace_back(db::schema_tables::parse_type(value));
+                }
+                auto ut = user_type_impl::get_instance(dst.name, name, columns, field_types, false);
+                return read_type_timestamp(dst, value_cast<sstring>(utf8_type->deserialize(name))).then([ut = std::move(ut), &dst](time_point timestamp) {
+                    dst.types.emplace_back(type{timestamp, ut});
+                });
+            }).finally([result] {});
+        });
+    }
+
+    future<> read_functions(keyspace& dst) {
+        auto query = fmt_query("SELECT * FROM {}.{} WHERE keyspace_name = ?", db::system_keyspace::legacy::FUNCTIONS);
+        return _qp.execute_internal(query, {dst.name}, cql3::query_processor::cache_internal::yes).then([](result_set_type result) {
+            if (!result->empty()) {
+                throw unsupported_feature("functions");
+            }
+        });
+    }
+
+    future<> read_aggregates(keyspace& dst) {
+        auto query = fmt_query("SELECT * FROM {}.{} WHERE keyspace_name = ?", db::system_keyspace::legacy::AGGREGATES);
+        return _qp.execute_internal(query, {dst.name}, cql3::query_processor::cache_internal::yes).then([](result_set_type result) {
+            if (!result->empty()) {
+                throw unsupported_feature("aggregates");
+            }
+        });
+    }
+
+    future<keyspace> read_keyspace(sstring ks_name, bool durable_writes, sstring strategy_class, sstring strategy_options, time_point timestamp) {
+        auto map = rjson::parse_to_map<std::map<sstring, sstring>>(std::string_view(strategy_options));
+        map.emplace("class", std::move(strategy_class));
+        auto ks = ::make_lw_shared<keyspace>(keyspace{timestamp, std::move(ks_name), durable_writes, std::move(map) });
+
+        return read_tables(*ks).then([this, ks] {
+            //Collection<Type> types = readTypes(keyspaceName);
+            return read_types(*ks);
+        }).then([this, ks] {
+            return read_functions(*ks);
+        }).then([this, ks] {
+            return read_aggregates(*ks);
+        }).then([ks] {
+            return make_ready_future<keyspace>(std::move(*ks));
+        });
+    }
+
+    future<> read_all_keyspaces() {
+        static auto ks_filter = [](row_type& row) {
+            auto ks_name = row.get_as<sstring>("keyspace_name");
+            return ks_name != db::system_keyspace::NAME && ks_name != db::schema_tables::v3::NAME;
+        };
+
+        auto query = fmt_query("SELECT keyspace_name, durable_writes, strategy_options, strategy_class, writeTime(durable_writes) AS timestamp FROM {}.{}",
+                        db::system_keyspace::legacy::KEYSPACES);
+
+        return _qp.execute_internal(query, cql3::query_processor::cache_internal::yes).then([this](result_set_type result) {
+            auto i = boost::make_filter_iterator(ks_filter, result->begin(), result->end());
+            auto e = boost::make_filter_iterator(ks_filter, result->end(), result->end());
+            return parallel_for_each(i, e, [this](row_type& row) {
+                return read_keyspace(row.get_as<sstring>("keyspace_name")
+                                , row.get_as<bool>("durable_writes")
+                                , row.get_as<sstring>("strategy_class")
+                                , row.get_as<sstring>("strategy_options")
+                                , row.get_as<db_clock::time_point>("timestamp")
+                                ).then([this](keyspace ks) {
+                    _keyspaces.emplace_back(std::move(ks));
+                   });
+            }).finally([result] {});
+        });
+    }
+
+    future<> drop_legacy_tables() {
+        mlogger.info("Dropping legacy schema tables");
+        auto with_snapshot = !_keyspaces.empty();
+        for (const sstring& cfname : legacy_schema_tables) {
+            co_await replica::database::legacy_drop_table_on_all_shards(_db, _sys_ks, db::system_keyspace::NAME, cfname, with_snapshot);
+        }
+    }
+
+    future<> store_keyspaces_in_new_schema_tables() {
+        mlogger.info("Moving {} keyspaces from legacy schema tables to the new schema keyspace ({})",
+                        _keyspaces.size(), db::schema_tables::v3::NAME);
+
+        utils::chunked_vector<mutation> mutations;
+
+        for (auto& ks : _keyspaces) {
+            auto ksm = ::make_lw_shared<keyspace_metadata>(ks.name
+                            , ks.replication_params["class"] // TODO, make ksm like c3?
+                            , cql3::statements::property_definitions::to_extended_map(ks.replication_params)
+                            , std::nullopt
+                            , std::nullopt
+                            , ks.durable_writes);
+
+            // we want separate time stamps for tables/types, so cannot bulk them into the ksm.
+            for (auto&& m : db::schema_tables::make_create_keyspace_mutations(schema_features::full(), ksm, ks.timestamp.time_since_epoch().count(), false)) {
+                mutations.emplace_back(std::move(m));
+            }
+            for (auto& t : ks.tables) {
+                db::schema_tables::add_table_or_view_to_schema_mutation(t.metadata, t.timestamp.time_since_epoch().count(), true, mutations);
+            }
+            for (auto& t : ks.types) {
+                db::schema_tables::add_type_to_schema_mutation(t.metadata, t.timestamp.time_since_epoch().count(), mutations);
+            }
+        }
+        return _qp.proxy().mutate_locally(std::move(mutations), tracing::trace_state_ptr());
+    }
+
+    future<> flush_schemas() {
+        auto& db = _qp.db().real_database().container();
+        return replica::database::flush_tables_on_all_shards(db, db::schema_tables::all_table_infos(schema_features::full()));
+    }
+
+    future<> migrate() {
+        return read_all_keyspaces().then([this]() {
+            // write metadata to the new schema tables
+            return store_keyspaces_in_new_schema_tables()
+                                                .then(std::bind(&migrator::flush_schemas, this))
+                                                .then(std::bind(&migrator::drop_legacy_tables, this))
+                                                .then([] { mlogger.info("Completed migration of legacy schema tables"); });
+        });
+    }
+
+    sharded<service::storage_proxy>& _sp;
+    sharded<replica::database>& _db;
+    sharded<db::system_keyspace>& _sys_ks;
+    cql3::query_processor& _qp;
+    std::vector<keyspace> _keyspaces;
+};
+
+const std::unordered_set<sstring> migrator::legacy_schema_tables = {
+                db::system_keyspace::legacy::KEYSPACES,
+                db::system_keyspace::legacy::COLUMNFAMILIES,
+                db::system_keyspace::legacy::COLUMNS,
+                db::system_keyspace::legacy::TRIGGERS,
+                db::system_keyspace::legacy::USERTYPES,
+                db::system_keyspace::legacy::FUNCTIONS,
+                db::system_keyspace::legacy::AGGREGATES,
+};
+
+}
+}
+
+future<>
+db::legacy_schema_migrator::migrate(sharded<service::storage_proxy>& sp, sharded<replica::database>& db, sharded<db::system_keyspace>& sys_ks, cql3::query_processor& qp) {
+    return do_with(migrator(sp, db, sys_ks, qp), std::bind(&migrator::migrate, std::placeholders::_1));
+}
+

db/legacy_schema_migrator.hh

@@ -0,0 +1,37 @@
+/*
+ * Modified by ScyllaDB
+ * Copyright (C) 2017-present ScyllaDB
+ */
+
+/*
+ * SPDX-License-Identifier: (LicenseRef-ScyllaDB-Source-Available-1.0 and Apache-2.0)
+ */
+
+#pragma once
+
+#include <seastar/core/future.hh>
+#include <seastar/core/sharded.hh>
+
+#include "seastarx.hh"
+
+namespace replica {
+class database;
+}
+
+namespace cql3 {
+class query_processor;
+}
+
+namespace service {
+class storage_proxy;
+}
+
+namespace db {
+class system_keyspace;
+
+namespace legacy_schema_migrator {
+
+future<> migrate(sharded<service::storage_proxy>&, sharded<replica::database>& db, sharded<db::system_keyspace>& sys_ks, cql3::query_processor&);
+
+}
+}

db/partition_snapshot_row_cursor.hh

@@ -542,7 +542,6 @@ public:
     // Returns the range tombstone for the key range adjacent to the cursor's position from the side of smaller keys.
     // Excludes the range for the row itself. That information is returned by range_tombstone_for_row().
     // It's possible that range_tombstone() is empty and range_tombstone_for_row() is not empty.
-    // Note that this is different from the meaning of rows_entry::range_tombstone(), which includes the row itself.
     tombstone range_tombstone() const { return _range_tombstone; }
 
     // Can be called when cursor is pointing at a row.

db/row_cache.cc

@@ -1287,15 +1287,6 @@ row_cache::row_cache(schema_ptr s, snapshot_source src, cache_tracker& tracker,
     , _partitions(dht::raw_token_less_comparator{})
     , _underlying(src())
     , _snapshot_source(std::move(src))
-    , _update_section(abstract_formatter([this] (fmt::context& ctx) {
-        fmt::format_to(ctx.out(), "cache.update {}.{}", _schema->ks_name(), _schema->cf_name());
-    }))
-    , _populate_section(abstract_formatter([this] (fmt::context& ctx) {
-        fmt::format_to(ctx.out(), "cache.populate {}.{}", _schema->ks_name(), _schema->cf_name());
-    }))
-    , _read_section(abstract_formatter([this] (fmt::context& ctx) {
-        fmt::format_to(ctx.out(), "cache.read {}.{}", _schema->ks_name(), _schema->cf_name());
-    }))
 {
   try {
     with_allocator(_tracker.allocator(), [this, cont] {

db/schema_tables.cc

@@ -404,7 +404,10 @@ const std::unordered_set<table_id>& schema_tables_holding_schema_mutations() {
                 computed_columns(),
                 dropped_columns(),
                 indexes(),
-                scylla_tables()}) {
+                scylla_tables(),
+                db::system_keyspace::legacy::column_families(),
+                db::system_keyspace::legacy::columns(),
+                db::system_keyspace::legacy::triggers()}) {
             SCYLLA_ASSERT(s->clustering_key_size() > 0);
             auto&& first_column_name = s->clustering_column_at(0).name_as_text();
             SCYLLA_ASSERT(first_column_name == "table_name"
@@ -2837,6 +2840,26 @@ void check_no_legacy_secondary_index_mv_schema(replica::database& db, const view
 }
 
 
+namespace legacy {
+
+table_schema_version schema_mutations::digest() const {
+    md5_hasher h;
+    const db::schema_features no_features;
+    db::schema_tables::feed_hash_for_schema_digest(h, _columnfamilies, no_features);
+    db::schema_tables::feed_hash_for_schema_digest(h, _columns, no_features);
+    return table_schema_version(utils::UUID_gen::get_name_UUID(h.finalize()));
+}
+
+future<schema_mutations> read_table_mutations(sharded<service::storage_proxy>& proxy,
+    sstring keyspace_name, sstring table_name, schema_ptr s)
+{
+    mutation cf_m = co_await read_schema_partition_for_table(proxy, s, keyspace_name, table_name);
+    mutation col_m = co_await read_schema_partition_for_table(proxy, db::system_keyspace::legacy::columns(), keyspace_name, table_name);
+    co_return schema_mutations{std::move(cf_m), std::move(col_m)};
+}
+
+} // namespace legacy
+
 static auto GET_COLUMN_MAPPING_QUERY = format("SELECT column_name, clustering_order, column_name_bytes, kind, position, type FROM system.{} WHERE cf_id = ? AND schema_version = ?",
     db::schema_tables::SCYLLA_TABLE_SCHEMA_HISTORY);
 

db/schema_tables.hh

@@ -155,6 +155,24 @@ schema_ptr scylla_table_schema_history();
 const std::unordered_set<table_id>& schema_tables_holding_schema_mutations();
 }
 
+namespace legacy {
+
+class schema_mutations {
+    mutation _columnfamilies;
+    mutation _columns;
+public:
+    schema_mutations(mutation columnfamilies, mutation columns)
+        : _columnfamilies(std::move(columnfamilies))
+        , _columns(std::move(columns))
+    { }
+    table_schema_version digest() const;
+};
+
+future<schema_mutations> read_table_mutations(sharded<service::storage_proxy>& proxy,
+    sstring keyspace_name, sstring table_name, schema_ptr s);
+
+}
+
 struct qualified_name {
     sstring keyspace_name;
     sstring table_name;

db/system_keyspace.cc

@@ -766,6 +766,9 @@ schema_ptr system_keyspace::size_estimates() {
         "partitions larger than specified threshold"
         );
         builder.set_gc_grace_seconds(0);
+        // FIXME re-enable caching for this and the other two
+        // system.large_* tables once
+        // https://github.com/scylladb/scylla/issues/3288 is fixed
         builder.set_caching_options(caching_options::get_disabled_caching_options());
         builder.with_hash_version();
         return builder.build(schema_builder::compact_storage::no);
@@ -847,6 +850,8 @@ schema_ptr system_keyspace::corrupt_data() {
     return corrupt_data;
 }
 
+static constexpr auto schema_gc_grace = std::chrono::duration_cast<std::chrono::seconds>(days(7)).count();
+
 /*static*/ schema_ptr system_keyspace::scylla_local() {
     static thread_local auto scylla_local = [] {
         schema_builder builder(generate_legacy_id(NAME, SCYLLA_LOCAL), NAME, SCYLLA_LOCAL,
@@ -1358,6 +1363,289 @@ schema_ptr system_keyspace::role_permissions() {
     return schema;
 }
 
+schema_ptr system_keyspace::legacy::hints() {
+    static thread_local auto schema = [] {
+        schema_builder builder(generate_legacy_id(NAME, HINTS), NAME, HINTS,
+        // partition key
+        {{"target_id", uuid_type}},
+        // clustering key
+        {{"hint_id", timeuuid_type}, {"message_version", int32_type}},
+        // regular columns
+        {{"mutation", bytes_type}},
+        // static columns
+        {},
+        // regular column name type
+        utf8_type,
+        // comment
+        "*DEPRECATED* hints awaiting delivery"
+       );
+       builder.set_gc_grace_seconds(0);
+       builder.set_compaction_strategy(compaction::compaction_strategy_type::incremental);
+       builder.set_compaction_strategy_options({{"enabled", "false"}});
+       builder.with(schema_builder::compact_storage::yes);
+       builder.with_hash_version();
+       return builder.build();
+    }();
+    return schema;
+}
+
+schema_ptr system_keyspace::legacy::batchlog() {
+    static thread_local auto schema = [] {
+        schema_builder builder(generate_legacy_id(NAME, BATCHLOG), NAME, BATCHLOG,
+        // partition key
+        {{"id", uuid_type}},
+        // clustering key
+        {},
+        // regular columns
+        {{"data", bytes_type}, {"version", int32_type}, {"written_at", timestamp_type}},
+        // static columns
+        {},
+        // regular column name type
+        utf8_type,
+        // comment
+        "*DEPRECATED* batchlog entries"
+       );
+       builder.set_gc_grace_seconds(0);
+       builder.set_compaction_strategy(compaction::compaction_strategy_type::incremental);
+       builder.set_compaction_strategy_options({{"min_threshold", "2"}});
+       builder.with(schema_builder::compact_storage::no);
+       builder.with_hash_version();
+       return builder.build();
+    }();
+    return schema;
+}
+
+schema_ptr system_keyspace::legacy::keyspaces() {
+    static thread_local auto schema = [] {
+        schema_builder builder(generate_legacy_id(NAME, KEYSPACES), NAME, KEYSPACES,
+        // partition key
+        {{"keyspace_name", utf8_type}},
+        // clustering key
+        {},
+        // regular columns
+        {
+         {"durable_writes", boolean_type},
+         {"strategy_class", utf8_type},
+         {"strategy_options", utf8_type}
+        },
+        // static columns
+        {},
+        // regular column name type
+        utf8_type,
+        // comment
+        "*DEPRECATED* keyspace definitions"
+       );
+       builder.set_gc_grace_seconds(schema_gc_grace);
+       builder.with(schema_builder::compact_storage::yes);
+       builder.with_hash_version();
+       return builder.build();
+    }();
+    return schema;
+}
+
+schema_ptr system_keyspace::legacy::column_families() {
+    static thread_local auto schema = [] {
+        schema_builder builder(generate_legacy_id(NAME, COLUMNFAMILIES), NAME, COLUMNFAMILIES,
+        // partition key
+        {{"keyspace_name", utf8_type}},
+        // clustering key
+        {{"columnfamily_name", utf8_type}},
+        // regular columns
+        {
+         {"bloom_filter_fp_chance", double_type},
+         {"caching", utf8_type},
+         {"cf_id", uuid_type},
+         {"comment", utf8_type},
+         {"compaction_strategy_class", utf8_type},
+         {"compaction_strategy_options", utf8_type},
+         {"comparator", utf8_type},
+         {"compression_parameters", utf8_type},
+         {"default_time_to_live", int32_type},
+         {"default_validator", utf8_type},
+         {"dropped_columns",  map_type_impl::get_instance(utf8_type, long_type, true)},
+         {"gc_grace_seconds", int32_type},
+         {"is_dense", boolean_type},
+         {"key_validator", utf8_type},
+         {"max_compaction_threshold", int32_type},
+         {"max_index_interval", int32_type},
+         {"memtable_flush_period_in_ms", int32_type},
+         {"min_compaction_threshold", int32_type},
+         {"min_index_interval", int32_type},
+         {"speculative_retry", utf8_type},
+         {"subcomparator", utf8_type},
+         {"type", utf8_type},
+         // The following 4 columns are only present up until 2.1.8 tables
+         {"key_aliases", utf8_type},
+         {"value_alias", utf8_type},
+         {"column_aliases", utf8_type},
+         {"index_interval", int32_type},},
+        // static columns
+        {},
+        // regular column name type
+        utf8_type,
+        // comment
+        "*DEPRECATED* table definitions"
+       );
+       builder.set_gc_grace_seconds(schema_gc_grace);
+       builder.with(schema_builder::compact_storage::no);
+       builder.with_hash_version();
+       return builder.build();
+    }();
+    return schema;
+}
+
+schema_ptr system_keyspace::legacy::columns() {
+    static thread_local auto schema = [] {
+        schema_builder builder(generate_legacy_id(NAME, COLUMNS), NAME, COLUMNS,
+        // partition key
+        {{"keyspace_name", utf8_type}},
+        // clustering key
+        {{"columnfamily_name", utf8_type}, {"column_name", utf8_type}},
+        // regular columns
+        {
+            {"component_index", int32_type},
+            {"index_name", utf8_type},
+            {"index_options", utf8_type},
+            {"index_type", utf8_type},
+            {"type", utf8_type},
+            {"validator", utf8_type},
+        },
+        // static columns
+        {},
+        // regular column name type
+        utf8_type,
+        // comment
+        "column definitions"
+        );
+        builder.set_gc_grace_seconds(schema_gc_grace);
+        builder.with(schema_builder::compact_storage::no);
+        builder.with_hash_version();
+        return builder.build();
+    }();
+    return schema;
+}
+
+schema_ptr system_keyspace::legacy::triggers() {
+    static thread_local auto schema = [] {
+        schema_builder builder(generate_legacy_id(NAME, TRIGGERS), NAME, TRIGGERS,
+        // partition key
+        {{"keyspace_name", utf8_type}},
+        // clustering key
+        {{"columnfamily_name", utf8_type}, {"trigger_name", utf8_type}},
+        // regular columns
+        {
+            {"trigger_options",  map_type_impl::get_instance(utf8_type, utf8_type, true)},
+        },
+        // static columns
+        {},
+        // regular column name type
+        utf8_type,
+        // comment
+        "trigger definitions"
+        );
+        builder.set_gc_grace_seconds(schema_gc_grace);
+        builder.with(schema_builder::compact_storage::no);
+        builder.with_hash_version();
+        return builder.build();
+    }();
+    return schema;
+}
+
+schema_ptr system_keyspace::legacy::usertypes() {
+    static thread_local auto schema = [] {
+        schema_builder builder(generate_legacy_id(NAME, USERTYPES), NAME, USERTYPES,
+        // partition key
+        {{"keyspace_name", utf8_type}},
+        // clustering key
+        {{"type_name", utf8_type}},
+        // regular columns
+        {
+            {"field_names", list_type_impl::get_instance(utf8_type, true)},
+            {"field_types", list_type_impl::get_instance(utf8_type, true)},
+        },
+        // static columns
+        {},
+        // regular column name type
+        utf8_type,
+        // comment
+        "user defined type definitions"
+        );
+        builder.set_gc_grace_seconds(schema_gc_grace);
+        builder.with(schema_builder::compact_storage::no);
+        builder.with_hash_version();
+        return builder.build();
+    }();
+    return schema;
+}
+
+schema_ptr system_keyspace::legacy::functions() {
+    /**
+     * Note: we have our own "legacy" version of this table (in schema_tables),
+     * but it is (afaik) not used, and differs slightly from the origin one.
+     * This is based on the origin schema, since we're more likely to encounter
+     * installations of that to migrate, rather than our own (if we dont use the table).
+     */
+    static thread_local auto schema = [] {
+        schema_builder builder(generate_legacy_id(NAME, FUNCTIONS), NAME, FUNCTIONS,
+        // partition key
+        {{"keyspace_name", utf8_type}},
+        // clustering key
+        {{"function_name", utf8_type},{"signature", list_type_impl::get_instance(utf8_type, false)}},
+        // regular columns
+        {
+            {"argument_names", list_type_impl::get_instance(utf8_type, true)},
+            {"argument_types", list_type_impl::get_instance(utf8_type, true)},
+            {"body", utf8_type},
+            {"language", utf8_type},
+            {"return_type", utf8_type},
+            {"called_on_null_input", boolean_type},
+        },
+        // static columns
+        {},
+        // regular column name type
+        utf8_type,
+        // comment
+        "*DEPRECATED* user defined type definitions"
+        );
+        builder.set_gc_grace_seconds(schema_gc_grace);
+        builder.with(schema_builder::compact_storage::no);
+        builder.with_hash_version();
+        return builder.build();
+    }();
+    return schema;
+}
+
+schema_ptr system_keyspace::legacy::aggregates() {
+    static thread_local auto schema = [] {
+        schema_builder builder(generate_legacy_id(NAME, AGGREGATES), NAME, AGGREGATES,
+        // partition key
+        {{"keyspace_name", utf8_type}},
+        // clustering key
+        {{"aggregate_name", utf8_type},{"signature", list_type_impl::get_instance(utf8_type, false)}},
+        // regular columns
+        {
+            {"argument_types", list_type_impl::get_instance(utf8_type, true)},
+            {"final_func", utf8_type},
+            {"initcond", bytes_type},
+            {"return_type", utf8_type},
+            {"state_func", utf8_type},
+            {"state_type", utf8_type},
+        },
+        // static columns
+        {},
+        // regular column name type
+        utf8_type,
+        // comment
+        "*DEPRECATED* user defined aggregate definition"
+        );
+        builder.set_gc_grace_seconds(schema_gc_grace);
+        builder.with(schema_builder::compact_storage::no);
+        builder.with_hash_version();
+        return builder.build();
+    }();
+    return schema;
+}
+
 schema_ptr system_keyspace::dicts() {
     static thread_local auto schema = [] {
         auto id = generate_legacy_id(NAME, DICTS);
@@ -1379,7 +1667,7 @@ schema_ptr system_keyspace::view_building_tasks() {
                 .with_column("key", utf8_type, column_kind::partition_key)
                 .with_column("id", timeuuid_type, column_kind::clustering_key)
                 .with_column("type", utf8_type)
-                .with_column("aborted", boolean_type)
+                .with_column("state", utf8_type)
                 .with_column("base_id", uuid_type)
                 .with_column("view_id", uuid_type)
                 .with_column("last_token", long_type)
@@ -2330,6 +2618,13 @@ std::vector<schema_ptr> system_keyspace::all_tables(const db::config& cfg) {
     if (cfg.check_experimental(db::experimental_features_t::feature::KEYSPACE_STORAGE_OPTIONS)) {
         r.insert(r.end(), {sstables_registry()});
     }
+    // legacy schema
+    r.insert(r.end(), {
+                    // TODO: once we migrate hints/batchlog and add converter
+                    // legacy::hints(), legacy::batchlog(),
+                    legacy::keyspaces(), legacy::column_families(),
+                    legacy::columns(), legacy::triggers(), legacy::usertypes(),
+                    legacy::functions(), legacy::aggregates(), });
 
     return r;
 }
@@ -2767,14 +3062,14 @@ future<mutation> system_keyspace::make_remove_view_build_status_on_host_mutation
 static constexpr auto VIEW_BUILDING_KEY = "view_building";
 
 future<db::view::building_tasks> system_keyspace::get_view_building_tasks() {
-    static const sstring query = format("SELECT id, type, aborted, base_id, view_id, last_token, host_id, shard FROM {}.{} WHERE key = '{}'", NAME, VIEW_BUILDING_TASKS, VIEW_BUILDING_KEY);
+    static const sstring query = format("SELECT id, type, state, base_id, view_id, last_token, host_id, shard FROM {}.{} WHERE key = '{}'", NAME, VIEW_BUILDING_TASKS, VIEW_BUILDING_KEY);
     using namespace db::view;
 
     building_tasks tasks;
     co_await _qp.query_internal(query, [&] (const cql3::untyped_result_set_row& row) -> future<stop_iteration> {
         auto id = row.get_as<utils::UUID>("id");
         auto type = task_type_from_string(row.get_as<sstring>("type"));
-        auto aborted = row.get_as<bool>("aborted");
+        auto state = task_state_from_string(row.get_as<sstring>("state"));
         auto base_id = table_id(row.get_as<utils::UUID>("base_id"));
         auto view_id = row.get_opt<utils::UUID>("view_id").transform([] (const utils::UUID& uuid) { return table_id(uuid); });
         auto last_token = dht::token::from_int64(row.get_as<int64_t>("last_token"));
@@ -2782,7 +3077,7 @@ future<db::view::building_tasks> system_keyspace::get_view_building_tasks() {
         auto shard = unsigned(row.get_as<int32_t>("shard"));
 
         locator::tablet_replica replica{host_id, shard};
-        view_building_task task{id, type, aborted, base_id, view_id, replica, last_token};
+        view_building_task task{id, type, state, base_id, view_id, replica, last_token};
 
         switch (type) {
         case db::view::view_building_task::task_type::build_range:
@@ -2801,7 +3096,7 @@ future<db::view::building_tasks> system_keyspace::get_view_building_tasks() {
 }
 
 future<mutation> system_keyspace::make_view_building_task_mutation(api::timestamp_type ts, const db::view::view_building_task& task) {
-    static const sstring stmt = format("INSERT INTO {}.{}(key, id, type, aborted, base_id, view_id, last_token, host_id, shard) VALUES ('{}', ?, ?, ?, ?, ?, ?, ?, ?)", NAME, VIEW_BUILDING_TASKS, VIEW_BUILDING_KEY);
+    static const sstring stmt = format("INSERT INTO {}.{}(key, id, type, state, base_id, view_id, last_token, host_id, shard) VALUES ('{}', ?, ?, ?, ?, ?, ?, ?, ?)", NAME, VIEW_BUILDING_TASKS, VIEW_BUILDING_KEY);
     using namespace db::view;
 
     data_value_or_unset view_id = unset_value{};
@@ -2812,7 +3107,7 @@ future<mutation> system_keyspace::make_view_building_task_mutation(api::timestam
         view_id = data_value(task.view_id->uuid());
     }
     auto muts = co_await _qp.get_mutations_internal(stmt, internal_system_query_state(), ts, {
-            task.id, task_type_to_sstring(task.type), task.aborted,
+            task.id, task_type_to_sstring(task.type), task_state_to_sstring(task.state),
             task.base_id.uuid(), view_id, dht::token::to_int64(task.last_token),
             task.replica.host.uuid(), int32_t(task.replica.shard)
     });
@@ -2822,6 +3117,18 @@ future<mutation> system_keyspace::make_view_building_task_mutation(api::timestam
     co_return std::move(muts[0]);
 }
 
+future<mutation> system_keyspace::make_update_view_building_task_state_mutation(api::timestamp_type ts, utils::UUID id, db::view::view_building_task::task_state state) {
+    static const sstring stmt = format("UPDATE {}.{} SET state = ? WHERE key = '{}' AND id = ?", NAME, VIEW_BUILDING_TASKS, VIEW_BUILDING_KEY);
+
+    auto muts = co_await _qp.get_mutations_internal(stmt, internal_system_query_state(), ts, {
+            task_state_to_sstring(state), id
+    });
+    if (muts.size() != 1) {
+        on_internal_error(slogger, fmt::format("expected 1 mutation got {}", muts.size()));
+    }
+    co_return std::move(muts[0]);
+}
+
 future<mutation> system_keyspace::make_remove_view_building_task_mutation(api::timestamp_type ts, utils::UUID id) {
     static const sstring stmt = format("DELETE FROM {}.{} WHERE key = '{}' AND id = ?", NAME, VIEW_BUILDING_TASKS, VIEW_BUILDING_KEY);
 

db/system_keyspace.hh

@@ -241,6 +241,28 @@ public:
         static schema_ptr cdc_local();
     };
 
+    struct legacy {
+        static constexpr auto HINTS = "hints";
+        static constexpr auto BATCHLOG = "batchlog";
+        static constexpr auto KEYSPACES = "schema_keyspaces";
+        static constexpr auto COLUMNFAMILIES = "schema_columnfamilies";
+        static constexpr auto COLUMNS = "schema_columns";
+        static constexpr auto TRIGGERS = "schema_triggers";
+        static constexpr auto USERTYPES = "schema_usertypes";
+        static constexpr auto FUNCTIONS = "schema_functions";
+        static constexpr auto AGGREGATES = "schema_aggregates";
+
+        static schema_ptr keyspaces();
+        static schema_ptr column_families();
+        static schema_ptr columns();
+        static schema_ptr triggers();
+        static schema_ptr usertypes();
+        static schema_ptr functions();
+        static schema_ptr aggregates();
+        static schema_ptr hints();
+        static schema_ptr batchlog();
+    };
+
     // Partition estimates for a given range of tokens.
     struct range_estimates {
         schema_ptr schema;
@@ -554,6 +576,7 @@ public:
     // system.view_building_tasks
     future<db::view::building_tasks> get_view_building_tasks();
     future<mutation> make_view_building_task_mutation(api::timestamp_type ts, const db::view::view_building_task& task);
+    future<mutation> make_update_view_building_task_state_mutation(api::timestamp_type ts, utils::UUID id, db::view::view_building_task::task_state state);
     future<mutation> make_remove_view_building_task_mutation(api::timestamp_type ts, utils::UUID id);
 
     // system.scylla_local, view_building_processing_base key

db/view/delete_ghost_rows_visitor.hh

@@ -9,8 +9,6 @@
 #include "query/query-result-reader.hh"
 #include "replica/database_fwd.hh"
 #include "db/timeout_clock.hh"
-#include <seastar/core/future.hh>
-#include <seastar/core/gate.hh>
 
 namespace service {
 class storage_proxy;
@@ -27,14 +25,8 @@ class delete_ghost_rows_visitor {
     replica::table& _view_table;
     schema_ptr _base_schema;
     std::optional<partition_key> _view_pk;
-    db::timeout_semaphore _concurrency_semaphore;
-    seastar::gate _gate;
-    std::exception_ptr& _ex;
-
 public:
-    delete_ghost_rows_visitor(service::storage_proxy& proxy, service::query_state& state, view_ptr view, db::timeout_clock::duration timeout_duration, size_t concurrency, std::exception_ptr& ex);
-    delete_ghost_rows_visitor(delete_ghost_rows_visitor&&) = default;
-    ~delete_ghost_rows_visitor() noexcept;
+    delete_ghost_rows_visitor(service::storage_proxy& proxy, service::query_state& state, view_ptr view, db::timeout_clock::duration timeout_duration);
 
     void add_value(const column_definition& def, query::result_row_view::iterator_type& i) {
     }
@@ -53,9 +45,6 @@ public:
     uint32_t accept_partition_end(const query::result_row_view& static_row) {
         return 0;
     }
-
-private:
-    future<> do_accept_new_row(partition_key pk,  clustering_key ck);
 };
 
 } //namespace db::view

db/view/view.cc

@@ -1744,115 +1744,6 @@ bool should_generate_view_updates_on_this_shard(const schema_ptr& base, const lo
         && std::ranges::contains(shards, this_shard_id());
 }
 
-static endpoints_to_update get_view_natural_endpoint_vnodes(
-        locator::host_id me,
-        std::vector<std::reference_wrapper<const locator::node>> base_nodes,
-        std::vector<std::reference_wrapper<const locator::node>> view_nodes,
-        locator::endpoint_dc_rack my_location,
-        const locator::network_topology_strategy* network_topology,
-        replica::cf_stats& cf_stats) {
-    using node_vector = std::vector<std::reference_wrapper<const locator::node>>;
-    node_vector base_endpoints, view_endpoints;
-    auto& my_datacenter = my_location.dc;
-
-    auto process_candidate = [&] (node_vector& nodes, std::reference_wrapper<const locator::node> node) {
-        if (!network_topology || node.get().dc() == my_datacenter) {
-            nodes.emplace_back(node);
-        }
-    };
-
-    for (auto&& base_node : base_nodes) {
-        process_candidate(base_endpoints, base_node);
-    }
-
-    for (auto&& view_node : view_nodes) {
-        auto it = std::ranges::find(base_endpoints, view_node.get().host_id(), std::mem_fn(&locator::node::host_id));
-        // If this base replica is also one of the view replicas, we use
-        // ourselves as the view replica.
-        // We don't return an extra endpoint, as it's only needed when
-        // using tablets (so !use_legacy_self_pairing)
-        if (view_node.get().host_id() == me && it != base_endpoints.end()) {
-            return {.natural_endpoint = me};
-        }
-
-        // We have to remove any endpoint which is shared between the base
-        // and the view, as it will select itself and throw off the counts
-        // otherwise.
-        if (it != base_endpoints.end()) {
-            base_endpoints.erase(it);
-        } else if (!network_topology || view_node.get().dc() == my_datacenter) {
-            view_endpoints.push_back(view_node);
-        }
-    }
-
-    auto base_it = std::ranges::find(base_endpoints, me, std::mem_fn(&locator::node::host_id));
-    if (base_it == base_endpoints.end()) {
-        // This node is not a base replica of this key, so we return empty
-        // FIXME: This case shouldn't happen, and if it happens, a view update
-        // would be lost.
-        ++cf_stats.total_view_updates_on_wrong_node;
-        vlogger.warn("Could not find {} in base_endpoints={}", me,
-                base_endpoints | std::views::transform(std::mem_fn(&locator::node::host_id)));
-        return {};
-    }
-    size_t idx = base_it - base_endpoints.begin();
-    return {.natural_endpoint = view_endpoints[idx].get().host_id()};
-}
-
-static std::optional<locator::host_id> get_unpaired_view_endpoint(
-        std::vector<std::reference_wrapper<const locator::node>> base_nodes,
-        std::vector<std::reference_wrapper<const locator::node>> view_nodes,
-        replica::cf_stats& cf_stats) {
-    std::unordered_set<locator::endpoint_dc_rack> base_dc_racks;
-    for (auto&& base_node : base_nodes) {
-        if (base_dc_racks.contains(base_node.get().dc_rack())) {
-            // We can't do rack-aware pairing if there are multiple replicas in the same rack.
-            ++cf_stats.total_view_updates_failed_pairing;
-            vlogger.warn("Can't perform base-view pairing in this topology. There are multiple base table replicas in the same dc/rack({}/{}):",
-                    base_node.get().dc(), base_node.get().rack());
-            return std::nullopt;
-        }
-        base_dc_racks.insert(base_node.get().dc_rack());
-    }
-
-    std::unordered_set<locator::endpoint_dc_rack> paired_view_dc_racks;
-    std::unordered_map<locator::endpoint_dc_rack, locator::host_id> unpaired_view_dc_rack_replicas;
-    for (auto&& view_node : view_nodes) {
-        if (paired_view_dc_racks.contains(view_node.get().dc_rack()) || unpaired_view_dc_rack_replicas.contains(view_node.get().dc_rack())) {
-            // We can't do rack-aware pairing if there are multiple replicas in the same rack.
-            ++cf_stats.total_view_updates_failed_pairing;
-            vlogger.warn("Can't perform base-view pairing in this topology. There are multiple view table replicas in the same dc/rack({}/{}):",
-                    view_node.get().dc(), view_node.get().rack());
-            return std::nullopt;
-        }
-        // Track unpaired replicas in both sets
-        if (base_dc_racks.contains(view_node.get().dc_rack())) {
-            paired_view_dc_racks.insert(view_node.get().dc_rack());
-        } else {
-            unpaired_view_dc_rack_replicas.insert({view_node.get().dc_rack(), view_node.get().host_id()});
-        }
-    }
-
-    if (unpaired_view_dc_rack_replicas.size() > 0) {
-        // There are view replicas that can't be paired with any base replica
-        // This can happen as a result of an RF change when the view replica finishes streaming
-        // before the base replica.
-        // Because of this, a view replica might not get paired with any base replica, so we need
-        // to send an additional update to it.
-        ++cf_stats.total_view_updates_due_to_replica_count_mismatch;
-        auto extra_replica = unpaired_view_dc_rack_replicas.begin()->second;
-        unpaired_view_dc_rack_replicas.erase(unpaired_view_dc_rack_replicas.begin());
-        if (unpaired_view_dc_rack_replicas.size() > 0) {
-            // We only expect one extra replica to appear due to an RF change. If there's more, that's an error,
-            // but we'll still perform updates to the paired and last replicas to minimize degradation.
-            vlogger.warn("There are too many view endpoints for base-view pairing. View updates may get lost on view_endpoints={}",
-                    unpaired_view_dc_rack_replicas | std::views::values);
-        }
-        return extra_replica;
-    }
-    return std::nullopt;
-}
-
 // Calculate the node ("natural endpoint") to which this node should send
 // a view update.
 //
@@ -1865,19 +1756,29 @@ static std::optional<locator::host_id> get_unpaired_view_endpoint(
 // of this function is to find, assuming that this node is one of the base
 // replicas for a given partition, the paired view replica.
 //
-// When using vnodes, we have an optimization called "self-pairing" - if a single
-// node is both a base replica and a view replica for a write, the pairing is
-// modified so that this node sends the update to itself and this node is removed
-// from the lists of nodes paired by index. This self-pairing optimization can
-// cause the pairing to change after view ranges are moved between nodes.
+// In the past, we used an optimization called "self-pairing" that if a single
+// node was both a base replica and a view replica for a write, the pairing is
+// modified so that this node would send the update to itself. This self-
+// pairing optimization could cause the pairing to change after view ranges
+// are moved between nodes, so currently we only use it if
+// use_legacy_self_pairing is set to true. When using tablets - where range
+// movements are common - it is strongly recommended to set it to false.
 //
 // If the keyspace's replication strategy is a NetworkTopologyStrategy,
 // we pair only nodes in the same datacenter.
 //
-// If the table uses tablets, then pairing is rack-aware. In this case, in each
-// rack where we have a base replica there is also one replica of each view tablet.
-// Therefore, the base replicas are naturally paired with the view replicas that
-// are in the same rack.
+// When use_legacy_self_pairing is enabled, if one of the base replicas
+// also happens to be a view replica, it is paired with itself
+// (with the other nodes paired by order in the list
+// after taking this node out).
+//
+// If the table uses tablets and the replication strategy is NetworkTopologyStrategy
+// and the replication factor in the node's datacenter is a multiple of the number
+// of racks in the datacenter, then pairing is rack-aware.  In this case,
+// all racks have the same number of replicas, and those are never migrated
+// outside their racks. Therefore, the base replicas are naturally paired with the
+// view replicas that are in the same rack, based on the ordinal position.
+// Note that typically, there is a single replica per rack and pairing is trivial.
 //
 // If the assumption that the given base token belongs to this replica
 // does not hold, we return an empty optional.
@@ -1905,12 +1806,19 @@ endpoints_to_update get_view_natural_endpoint(
         const locator::abstract_replication_strategy& replication_strategy,
         const dht::token& base_token,
         const dht::token& view_token,
-        bool use_tablets,
+        bool use_legacy_self_pairing,
+        bool use_tablets_rack_aware_view_pairing,
         replica::cf_stats& cf_stats) {
     auto& topology = base_erm->get_token_metadata_ptr()->get_topology();
     auto& view_topology = view_erm->get_token_metadata_ptr()->get_topology();
     auto& my_location = topology.get_location(me);
+    auto& my_datacenter = my_location.dc;
     auto* network_topology = dynamic_cast<const locator::network_topology_strategy*>(&replication_strategy);
+    auto rack_aware_pairing = use_tablets_rack_aware_view_pairing && network_topology;
+    bool simple_rack_aware_pairing = false;
+    using node_vector = std::vector<std::reference_wrapper<const locator::node>>;
+    node_vector orig_base_endpoints, orig_view_endpoints;
+    node_vector base_endpoints, view_endpoints;
 
     auto resolve = [&] (const locator::topology& topology, const locator::host_id& ep, bool is_view) -> const locator::node& {
         if (auto* np = topology.find_node(ep)) {
@@ -1921,7 +1829,6 @@ endpoints_to_update get_view_natural_endpoint(
 
     // We need to use get_replicas() for pairing to be stable in case base or view tablet
     // is rebuilding a replica which has left the ring. get_natural_endpoints() filters such replicas.
-    using node_vector = std::vector<std::reference_wrapper<const locator::node>>;
     auto base_nodes = base_erm->get_replicas(base_token) | std::views::transform([&] (const locator::host_id& ep) -> const locator::node& {
         return resolve(topology, ep, false);
     }) | std::ranges::to<node_vector>();
@@ -1945,43 +1852,231 @@ endpoints_to_update get_view_natural_endpoint(
                 // note that the recursive call will not recurse again because leaving_base is in base_nodes.
                 auto leaving_base = it->get().host_id();
                 return get_view_natural_endpoint(leaving_base, base_erm, view_erm, replication_strategy, base_token,
-                        view_token, use_tablets, cf_stats);
+                        view_token, use_legacy_self_pairing, use_tablets_rack_aware_view_pairing, cf_stats);
             }
         }
     }
 
-    if (!use_tablets) {
-        return get_view_natural_endpoint_vnodes(
-                me,
-                base_nodes,
-                view_nodes,
-                my_location,
-                network_topology,
-                cf_stats);
+    std::function<bool(const locator::node&)> is_candidate;
+    if (network_topology) {
+        is_candidate = [&] (const locator::node& node) { return node.dc() == my_datacenter; };
+    } else {
+        is_candidate = [&] (const locator::node&) { return true; };
+    }
+    auto process_candidate = [&] (node_vector& nodes, std::reference_wrapper<const locator::node> node) {
+        if (is_candidate(node)) {
+            nodes.emplace_back(node);
+        }
+    };
+
+    for (auto&& base_node : base_nodes) {
+        process_candidate(base_endpoints, base_node);
     }
 
-    std::optional<locator::host_id> paired_replica;
-    for (auto&& view_node : view_nodes) {
-        if (view_node.get().dc_rack() == my_location) {
-            paired_replica = view_node.get().host_id();
-            break;
+    if (use_legacy_self_pairing) {
+        for (auto&& view_node : view_nodes) {
+            auto it = std::ranges::find(base_endpoints, view_node.get().host_id(), std::mem_fn(&locator::node::host_id));
+            // If this base replica is also one of the view replicas, we use
+            // ourselves as the view replica.
+            // We don't return an extra endpoint, as it's only needed when
+            // using tablets (so !use_legacy_self_pairing)
+            if (view_node.get().host_id() == me && it != base_endpoints.end()) {
+                return {.natural_endpoint = me};
+            }
+
+            // We have to remove any endpoint which is shared between the base
+            // and the view, as it will select itself and throw off the counts
+            // otherwise.
+            if (it != base_endpoints.end()) {
+                base_endpoints.erase(it);
+            } else if (is_candidate(view_node)) {
+                view_endpoints.push_back(view_node);
+            }
+        }
+    } else {
+        for (auto&& view_node : view_nodes) {
+            process_candidate(view_endpoints, view_node);
         }
     }
-    if (paired_replica && base_nodes.size() == view_nodes.size()) {
-        // We don't need to find any extra replicas, so we can return early
-        return {.natural_endpoint = paired_replica};
+
+    // Try optimizing for simple rack-aware pairing
+    // If the numbers of base and view replica differ, that means an RF change is taking place
+    // and we can't use simple rack-aware pairing.
+    if (rack_aware_pairing && base_endpoints.size() == view_endpoints.size()) {
+        auto dc_rf = network_topology->get_replication_factor(my_datacenter);
+        const auto& racks = topology.get_datacenter_rack_nodes().at(my_datacenter);
+        // Simple rack-aware pairing is possible when the datacenter replication factor
+        // is a multiple of the number of racks in the datacenter.
+        if (dc_rf % racks.size() == 0) {
+            simple_rack_aware_pairing = true;
+            size_t rack_rf = dc_rf / racks.size();
+            // If any rack doesn't have enough nodes to satisfy the per-rack rf
+            // simple rack-aware pairing is disabled.
+            for (const auto& [rack, nodes] : racks) {
+                if (nodes.size() < rack_rf) {
+                    simple_rack_aware_pairing = false;
+                    break;
+                }
+            }
+        }
+        if (dc_rf != base_endpoints.size()) {
+            // If the datacenter replication factor is not equal to the number of base replicas,
+            // we're in progress of a RF change and we can't use simple rack-aware pairing.
+            simple_rack_aware_pairing = false;
+        }
+        if (simple_rack_aware_pairing) {
+            std::erase_if(base_endpoints, [&] (const locator::node& node) { return node.dc_rack() != my_location; });
+            std::erase_if(view_endpoints, [&] (const locator::node& node) { return node.dc_rack() != my_location; });
+        }
     }
-    if (!paired_replica) {
-        // We couldn't find any view replica in our rack
+
+    orig_base_endpoints = base_endpoints;
+    orig_view_endpoints = view_endpoints;
+
+    // For the complex rack_aware_pairing case, nodes are already filtered by datacenter
+    // Use best-match, for the minimum number of base and view replicas in each rack,
+    // and ordinal match for the rest.
+    std::optional<std::reference_wrapper<const locator::node>> paired_replica;
+    if (rack_aware_pairing && !simple_rack_aware_pairing) {
+        struct indexed_replica {
+            size_t idx;
+            std::reference_wrapper<const locator::node> node;
+        };
+        std::unordered_map<sstring, std::vector<indexed_replica>> base_racks, view_racks;
+
+        // First, index all replicas by rack
+        auto index_replica_set = [] (std::unordered_map<sstring, std::vector<indexed_replica>>& racks, const node_vector& replicas) {
+            size_t idx = 0;
+            for (const auto& r: replicas) {
+                racks[r.get().rack()].emplace_back(idx++, r);
+            }
+        };
+        index_replica_set(base_racks, base_endpoints);
+        index_replica_set(view_racks, view_endpoints);
+
+        // Try optimistically pairing `me` first
+        const auto& my_base_replicas = base_racks[my_location.rack];
+        auto base_it = std::ranges::find(my_base_replicas, me, [] (const indexed_replica& ir) { return ir.node.get().host_id(); });
+        if (base_it == my_base_replicas.end()) {
+            return {};
+        }
+        const auto& my_view_replicas = view_racks[my_location.rack];
+        size_t idx = base_it - my_base_replicas.begin();
+        if (idx < my_view_replicas.size()) {
+            if (orig_view_endpoints.size() <= orig_base_endpoints.size()) {
+                return {.natural_endpoint = my_view_replicas[idx].node.get().host_id()};
+            } else {
+                // If the number of view replicas is larger than the number of base replicas,
+                // we need to find the unpaired view replica, so we can't return yet.
+                paired_replica = my_view_replicas[idx].node;
+            }
+        }
+
+        // Collect all unpaired base and view replicas,
+        // where the number of replicas in the base rack is different than the respective view rack
+        std::vector<indexed_replica> unpaired_base_replicas, unpaired_view_replicas;
+        for (const auto& [rack, base_replicas] : base_racks) {
+            const auto& view_replicas = view_racks[rack];
+            for (auto i = view_replicas.size(); i < base_replicas.size(); ++i) {
+                unpaired_base_replicas.emplace_back(base_replicas[i]);
+            }
+        }
+        for (const auto& [rack, view_replicas] : view_racks) {
+            const auto& base_replicas = base_racks[rack];
+            for (auto i = base_replicas.size(); i < view_replicas.size(); ++i) {
+                unpaired_view_replicas.emplace_back(view_replicas[i]);
+            }
+        }
+
+        // Sort by the original ordinality, and copy the sorted results
+        // back into {base,view}_endpoints, for backward compatible processing below.
+        std::ranges::sort(unpaired_base_replicas, std::less(), std::mem_fn(&indexed_replica::idx));
+        base_endpoints.clear();
+        std::ranges::transform(unpaired_base_replicas, std::back_inserter(base_endpoints), std::mem_fn(&indexed_replica::node));
+
+        std::ranges::sort(unpaired_view_replicas, std::less(), std::mem_fn(&indexed_replica::idx));
+        view_endpoints.clear();
+        std::ranges::transform(unpaired_view_replicas, std::back_inserter(view_endpoints), std::mem_fn(&indexed_replica::node));
+    }
+
+    auto base_it = std::ranges::find(base_endpoints, me, std::mem_fn(&locator::node::host_id));
+    if (!paired_replica && base_it == base_endpoints.end()) {
+        // This node is not a base replica of this key, so we return empty
+        // FIXME: This case shouldn't happen, and if it happens, a view update
+        // would be lost.
+        ++cf_stats.total_view_updates_on_wrong_node;
+        vlogger.warn("Could not find {} in base_endpoints={}", me,
+                orig_base_endpoints | std::views::transform(std::mem_fn(&locator::node::host_id)));
+        return {};
+    }
+    size_t idx = base_it - base_endpoints.begin();
+    std::optional<std::reference_wrapper<const locator::node>> no_pairing_replica;
+    if (!paired_replica && idx >= view_endpoints.size()) {
+        // There are fewer view replicas than base replicas
+        // FIXME: This might still happen when reducing replication factor with tablets,
+        // see https://github.com/scylladb/scylladb/issues/21492
         ++cf_stats.total_view_updates_failed_pairing;
-        vlogger.warn("Could not find a view replica in the same rack as base replica {} for base_endpoints={} view_endpoints={}", 
-                me,
-                base_nodes | std::views::transform(std::mem_fn(&locator::node::host_id)),
-                view_nodes | std::views::transform(std::mem_fn(&locator::node::host_id)));
+        vlogger.warn("Could not pair {}: rack_aware={} base_endpoints={} view_endpoints={}", me,
+                rack_aware_pairing ? (simple_rack_aware_pairing ? "simple" : "complex") : "none",
+                orig_base_endpoints | std::views::transform(std::mem_fn(&locator::node::host_id)),
+                orig_view_endpoints | std::views::transform(std::mem_fn(&locator::node::host_id)));
+        return {};
+    } else if (base_endpoints.size() < view_endpoints.size()) {
+        // There are fewer base replicas than view replicas.
+        // This can happen as a result of an RF change when the view replica finishes streaming
+        // before the base replica.
+        // Because of this, a view replica might not get paired with any base replica, so we need
+        // to send an additional update to it.
+        ++cf_stats.total_view_updates_due_to_replica_count_mismatch;
+        no_pairing_replica = view_endpoints.back();
+        if (base_endpoints.size() < view_endpoints.size() - 1) {
+            // We only expect one extra replica to appear due to an RF change. If there's more, that's an error,
+            // but we'll still perform updates to the paired and last replicas to minimize degradation.
+            vlogger.warn("There are too many view endpoints for base-view pairing. View updates may get lost on view_endpoints={}",
+                    std::span(view_endpoints.begin() + base_endpoints.size(), view_endpoints.end() - 1) | std::views::transform(std::mem_fn(&locator::node::host_id)));
+        }
     }
-    std::optional<locator::host_id> no_pairing_replica = get_unpaired_view_endpoint(base_nodes, view_nodes, cf_stats);
-    return {.natural_endpoint = paired_replica,
-            .endpoint_with_no_pairing = no_pairing_replica};
+
+    if (!paired_replica) {
+        paired_replica = view_endpoints[idx];
+    }
+    if (!no_pairing_replica && base_nodes.size() < view_nodes.size()) {
+        // This can happen when the view replica with no pairing is in another DC.
+        // We need to send an update to it if there are no base replicas in that DC yet,
+        // as it won't receive updates otherwise.
+        std::unordered_set<sstring> dcs_with_base_replicas;
+        for (const auto& base_node : base_nodes) {
+            dcs_with_base_replicas.insert(base_node.get().dc());
+        }
+        for (const auto& view_node : view_nodes) {
+            if (!dcs_with_base_replicas.contains(view_node.get().dc())) {
+                ++cf_stats.total_view_updates_due_to_replica_count_mismatch;
+                no_pairing_replica = view_node;
+                break;
+            }
+        }
+    }
+    // https://github.com/scylladb/scylladb/issues/19439
+    // With tablets, a node being replaced might transition to "left" state
+    // but still be kept as a replica.
+    // As of writing this hints are not prepared to handle nodes that are left
+    // but are still replicas. Therefore, there is no other sensible option
+    // right now but to give up attempt to send the update or write a hint
+    // to the paired, permanently down replica.
+    // We use the same workaround for the extra replica.
+    auto return_host_id_if_not_left = [] (const auto& replica) -> std::optional<locator::host_id> {
+        if (!replica) {
+            return std::nullopt;
+        }
+        const auto& node = replica->get();
+        if (!node.left()) {
+            return node.host_id();
+        } else {
+            return std::nullopt;
+        }
+    };
+    return {.natural_endpoint = return_host_id_if_not_left(paired_replica),
+            .endpoint_with_no_pairing = return_host_id_if_not_left(no_pairing_replica)};
 }
 
 static future<> apply_to_remote_endpoints(service::storage_proxy& proxy, locator::effective_replication_map_ptr ermp,
@@ -2041,6 +2136,12 @@ future<> view_update_generator::mutate_MV(
 {
     auto& ks = _db.find_keyspace(base->ks_name());
     auto& replication = ks.get_replication_strategy();
+    // We set legacy self-pairing for old vnode-based tables (for backward
+    // compatibility), and unset it for tablets - where range movements
+    // are more frequent and backward compatibility is less important.
+    // TODO: Maybe allow users to set use_legacy_self_pairing explicitly
+    // on a view, like we have the synchronous_updates_flag.
+    bool use_legacy_self_pairing = !ks.uses_tablets();
     std::unordered_map<table_id, locator::effective_replication_map_ptr> erms;
     auto get_erm = [&] (table_id id) {
         auto it = erms.find(id);
@@ -2053,6 +2154,10 @@ future<> view_update_generator::mutate_MV(
     for (const auto& mut : view_updates) {
         (void)get_erm(mut.s->id());
     }
+    // Enable rack-aware view updates pairing for tablets
+    // when the cluster feature is enabled so that all replicas agree
+    // on the pairing algorithm.
+    bool use_tablets_rack_aware_view_pairing = _db.features().tablet_rack_aware_view_pairing && ks.uses_tablets();
     auto me = base_ermp->get_topology().my_host_id();
     static constexpr size_t max_concurrent_updates = 128;
     co_await utils::get_local_injector().inject("delay_before_get_view_natural_endpoint", 8000ms);
@@ -2060,7 +2165,7 @@ future<> view_update_generator::mutate_MV(
         auto view_token = dht::get_token(*mut.s, mut.fm.key());
         auto view_ermp = erms.at(mut.s->id());
         auto [target_endpoint, no_pairing_endpoint] = get_view_natural_endpoint(me, base_ermp, view_ermp, replication, base_token, view_token,
-                ks.uses_tablets(), cf_stats);
+                use_legacy_self_pairing, use_tablets_rack_aware_view_pairing, cf_stats);
         auto remote_endpoints = view_ermp->get_pending_replicas(view_token);
         auto memory_units = seastar::make_lw_shared<db::timeout_semaphore_units>(pending_view_update_memory_units.split(memory_usage_of(mut)));
         if (no_pairing_endpoint) {
@@ -3492,7 +3597,7 @@ view_updating_consumer::view_updating_consumer(view_update_generator& gen, schem
     })
 { }
 
-delete_ghost_rows_visitor::delete_ghost_rows_visitor(service::storage_proxy& proxy, service::query_state& state, view_ptr view, db::timeout_clock::duration timeout_duration, size_t concurrency, std::exception_ptr& ex)
+delete_ghost_rows_visitor::delete_ghost_rows_visitor(service::storage_proxy& proxy, service::query_state& state, view_ptr view, db::timeout_clock::duration timeout_duration)
         : _proxy(proxy)
         , _state(state)
         , _timeout_duration(timeout_duration)
@@ -3500,20 +3605,8 @@ delete_ghost_rows_visitor::delete_ghost_rows_visitor(service::storage_proxy& pro
         , _view_table(_proxy.get_db().local().find_column_family(view))
         , _base_schema(_proxy.get_db().local().find_schema(_view->view_info()->base_id()))
         , _view_pk()
-        , _concurrency_semaphore(concurrency)
-        , _ex(ex)
 {}
 
-
-delete_ghost_rows_visitor::~delete_ghost_rows_visitor() noexcept {
-    try {
-        _gate.close().get();
-    } catch (...) {
-        // Closing the gate should never throw, but if it does anyway, capture the exception.
-        _ex = std::current_exception();
-    }
-}
-
 void delete_ghost_rows_visitor::accept_new_partition(const partition_key& key, uint32_t row_count) {
     SCYLLA_ASSERT(thread::running_in_thread());
     _view_pk = key;
@@ -3521,18 +3614,7 @@ void delete_ghost_rows_visitor::accept_new_partition(const partition_key& key, u
 
 // Assumes running in seastar::thread
 void delete_ghost_rows_visitor::accept_new_row(const clustering_key& ck, const query::result_row_view& static_row, const query::result_row_view& row) {
-    auto units = get_units(_concurrency_semaphore, 1).get();
-    (void)seastar::try_with_gate(_gate, [this, pk = _view_pk.value(), units = std::move(units), ck] () mutable {
-        return do_accept_new_row(std::move(pk), std::move(ck)).then_wrapped([this, units = std::move(units)] (future<>&& f) mutable {
-            if (f.failed()) {
-                _ex = f.get_exception();
-            }
-        });
-    });
-}
-
-future<> delete_ghost_rows_visitor::do_accept_new_row(partition_key pk, clustering_key ck) {
-    auto view_exploded_pk = pk.explode();
+    auto view_exploded_pk = _view_pk->explode();
     auto view_exploded_ck = ck.explode();
     std::vector<bytes> base_exploded_pk(_base_schema->partition_key_size());
     std::vector<bytes> base_exploded_ck(_base_schema->clustering_key_size());
@@ -3567,17 +3649,17 @@ future<> delete_ghost_rows_visitor::do_accept_new_row(partition_key pk, clusteri
             _proxy.get_max_result_size(partition_slice), query::tombstone_limit(_proxy.get_tombstone_limit()));
     auto timeout = db::timeout_clock::now() + _timeout_duration;
     service::storage_proxy::coordinator_query_options opts{timeout, _state.get_permit(), _state.get_client_state(), _state.get_trace_state()};
-    auto base_qr = co_await _proxy.query(_base_schema, command, std::move(partition_ranges), db::consistency_level::ALL, opts);
+    auto base_qr = _proxy.query(_base_schema, command, std::move(partition_ranges), db::consistency_level::ALL, opts).get();
     query::result& result = *base_qr.query_result;
-    auto delete_ghost_row = [&]() -> future<> {
-        mutation m(_view, pk);
+    auto delete_ghost_row = [&]() {
+        mutation m(_view, *_view_pk);
         auto& row = m.partition().clustered_row(*_view, ck);
         row.apply(tombstone(api::new_timestamp(), gc_clock::now()));
         timeout = db::timeout_clock::now() + _timeout_duration;
-        return _proxy.mutate({m}, db::consistency_level::ALL, timeout, _state.get_trace_state(), empty_service_permit(), db::allow_per_partition_rate_limit::no);
+        _proxy.mutate({m}, db::consistency_level::ALL, timeout, _state.get_trace_state(), empty_service_permit(), db::allow_per_partition_rate_limit::no).get();
     };
     if (result.row_count().value_or(0) == 0) {
-        co_await delete_ghost_row();
+        delete_ghost_row();
     } else if (!view_key_cols_not_in_base_key.empty()) {
         if (result.row_count().value_or(0) != 1) {
             on_internal_error(vlogger, format("Got multiple base rows corresponding to a single view row when pruning {}.{}", _view->ks_name(), _view->cf_name()));
@@ -3587,7 +3669,7 @@ future<> delete_ghost_rows_visitor::do_accept_new_row(partition_key pk, clusteri
         for (const auto& [col_def, col_val] : view_key_cols_not_in_base_key) {
             const data_value* base_val = base_row.get_data_value(col_def->name_as_text());
             if (!base_val || base_val->is_null() || col_val != base_val->serialize_nonnull()) {
-                co_await delete_ghost_row();
+                delete_ghost_row();
                 break;
             }
         }

db/view/view.hh

@@ -305,7 +305,8 @@ endpoints_to_update get_view_natural_endpoint(
     const locator::abstract_replication_strategy& replication_strategy,
     const dht::token& base_token,
     const dht::token& view_token,
-    bool use_tablets,
+    bool use_legacy_self_pairing,
+    bool use_tablets_basic_rack_aware_view_pairing,
     replica::cf_stats& cf_stats);
 
 /// Verify that the provided keyspace is eligible for storing materialized views.

db/view/view_building_coordinator.cc

@@ -104,8 +104,6 @@ future<> view_building_coordinator::run() {
         _vb_sm.event.broadcast();
     });
 
-    auto finished_tasks_gc_fiber = finished_task_gc_fiber();
-
     while (!_as.abort_requested()) {
         co_await utils::get_local_injector().inject("view_building_coordinator_pause_main_loop", utils::wait_for_message(std::chrono::minutes(2)));
         if (utils::get_local_injector().enter("view_building_coordinator_skip_main_loop")) {
@@ -123,7 +121,12 @@ future<> view_building_coordinator::run() {
                 continue;
             }
 
-            co_await work_on_view_building(std::move(*guard_opt));
+            auto started_new_work = co_await work_on_view_building(std::move(*guard_opt));
+            if (started_new_work) {
+                // If any tasks were started, do another iteration, so the coordinator can attach itself to the tasks (via RPC)
+                vbc_logger.debug("view building coordinator started new tasks, do next iteration without waiting for event");
+                continue;
+            }
             co_await await_event();
         } catch (...) {
             handle_coordinator_error(std::current_exception());
@@ -139,66 +142,6 @@ future<> view_building_coordinator::run() {
             }
         }
     }
-
-    co_await std::move(finished_tasks_gc_fiber);
-}
-
-future<> view_building_coordinator::finished_task_gc_fiber() {
-    static auto task_gc_interval = 200ms;
-
-    while (!_as.abort_requested()) {
-        try {
-            co_await clean_finished_tasks();
-            co_await sleep_abortable(task_gc_interval, _as);
-        } catch (abort_requested_exception&) {
-            vbc_logger.debug("view_building_coordinator::finished_task_gc_fiber got abort_requested_exception");
-        } catch (service::group0_concurrent_modification&) {
-            vbc_logger.info("view_building_coordinator::finished_task_gc_fiber got group0_concurrent_modification");
-        } catch (raft::request_aborted&) {
-            vbc_logger.debug("view_building_coordinator::finished_task_gc_fiber got raft::request_aborted");
-        } catch (service::term_changed_error&) {
-            vbc_logger.debug("view_building_coordinator::finished_task_gc_fiber notices term change {} -> {}", _term, _raft.get_current_term());
-        } catch (raft::commit_status_unknown&) {
-            vbc_logger.warn("view_building_coordinator::finished_task_gc_fiber got raft::commit_status_unknown");
-        } catch (...) {
-            vbc_logger.error("view_building_coordinator::finished_task_gc_fiber got error: {}", std::current_exception());
-        }
-    }
-}
-
-future<> view_building_coordinator::clean_finished_tasks() {
-    // Avoid acquiring a group0 operation if there are no tasks.
-    if (_finished_tasks.empty()) {
-        co_return;
-    }
-
-    auto guard = co_await start_operation();
-    auto lock = co_await get_unique_lock(_mutex);
-
-    if (!_vb_sm.building_state.currently_processed_base_table || std::ranges::all_of(_finished_tasks, [] (auto& e) { return e.second.empty(); })) {
-        co_return;
-    }
-
-    view_building_task_mutation_builder builder(guard.write_timestamp());
-    for (auto& [replica, tasks]: _finished_tasks) {
-        for (auto& task_id: tasks) {
-            // The task might be aborted in the meantime. In this case we cannot remove it because we need it to create a new task.
-            //
-            // TODO: When we're aborting a view building task (for instance due to tablet migration),
-            //       we can look if we already finished it (check if it's in `_finished_tasks`).
-            //       If yes, we can just remove it instead of aborting it.
-            auto task_opt = _vb_sm.building_state.get_task(*_vb_sm.building_state.currently_processed_base_table, replica, task_id);
-            if (task_opt && !task_opt->get().aborted) {
-                builder.del_task(task_id);
-                vbc_logger.debug("Removing finished task with ID: {}", task_id);
-            }
-        }
-    }
-
-    co_await commit_mutations(std::move(guard), {builder.build()}, "remove finished view building tasks");
-    for (auto& [_, tasks_set]: _finished_tasks) {
-        tasks_set.clear();
-    }
 }
 
 future<std::optional<service::group0_guard>> view_building_coordinator::update_state(service::group0_guard guard) {
@@ -358,16 +301,18 @@ future<> view_building_coordinator::update_views_statuses(const service::group0_
     }
 }
 
-future<> view_building_coordinator::work_on_view_building(service::group0_guard guard) {
+future<bool> view_building_coordinator::work_on_view_building(service::group0_guard guard) {
     if (!_vb_sm.building_state.currently_processed_base_table) {
         vbc_logger.debug("No base table is selected, nothing to do.");
-        co_return;
+        co_return false;
     }
 
-    // Acquire unique lock of `_finished_tasks` to ensure each replica has its own entry in it
-    // and to select tasks for them.
-    auto lock = co_await get_unique_lock(_mutex);
+    utils::chunked_vector<mutation> muts;
+    std::unordered_set<locator::tablet_replica> _remote_work_keys_to_erase;
     for (auto& replica: get_replicas_with_tasks()) {
+        // Check whether the coordinator already waits for the remote work on the replica to be finished.
+        // If so: check if the work is done and and remove the shared_future, skip this replica otherwise.
+        bool skip_work_on_this_replica = false;
         if (_remote_work.contains(replica)) {
             if (!_remote_work[replica].available()) {
                 vbc_logger.debug("Replica {} is still doing work", replica);
@@ -375,7 +320,21 @@ future<> view_building_coordinator::work_on_view_building(service::group0_guard
             }
 
             auto remote_results_opt = co_await _remote_work[replica].get_future();
-            _remote_work.erase(replica);
+            if (remote_results_opt) {
+                auto results_muts = co_await update_state_after_work_is_done(guard, replica, std::move(*remote_results_opt));
+                muts.insert(muts.end(), std::make_move_iterator(results_muts.begin()), std::make_move_iterator(results_muts.end()));
+                // If the replica successfully finished its work, we need to commit mutations generated above before selecting next task
+                skip_work_on_this_replica = !results_muts.empty();
+            }
+
+            // If there were no mutations for this replica, we can just remove the entry from `_remote_work` map
+            // and start new work in the same iteration.
+            // Otherwise, the entry needs to be removed after the mutations are committed successfully.
+            if (skip_work_on_this_replica) {
+                _remote_work_keys_to_erase.insert(replica);
+            } else {
+                _remote_work.erase(replica);
+            }
         }
 
         const bool ignore_gossiper = utils::get_local_injector().enter("view_building_coordinator_ignore_gossiper");
@@ -384,16 +343,31 @@ future<> view_building_coordinator::work_on_view_building(service::group0_guard
             continue;
         }
 
-        if (!_finished_tasks.contains(replica)) {
-            _finished_tasks.insert({replica, {}});
+        if (skip_work_on_this_replica) {
+            continue;
         }
 
-        if (auto todo_ids = select_tasks_for_replica(replica); !todo_ids.empty()) {
-            start_remote_worker(replica, std::move(todo_ids));
+        if (auto already_started_ids = _vb_sm.building_state.get_started_tasks(*_vb_sm.building_state.currently_processed_base_table, replica); !already_started_ids.empty()) {
+            // If the replica has any task in `STARTED` state, attach the coordinator to the work.
+            attach_to_started_tasks(replica, std::move(already_started_ids));
+        } else if (auto todo_ids = select_tasks_for_replica(replica); !todo_ids.empty()) {
+            // If the replica has no started tasks and there are tasks to do, mark them as started.
+            // The coordinator will attach itself to the work in next iteration.
+            auto new_mutations = co_await start_tasks(guard, std::move(todo_ids));
+            muts.insert(muts.end(), std::make_move_iterator(new_mutations.begin()), std::make_move_iterator(new_mutations.end()));
         } else {
             vbc_logger.debug("Nothing to do for replica {}", replica);
         }
     }
+
+    if (!muts.empty()) {
+        co_await commit_mutations(std::move(guard), std::move(muts), "start view building tasks");
+        for (auto& key: _remote_work_keys_to_erase) {
+            _remote_work.erase(key);
+        }
+        co_return true;
+    }
+    co_return false;
 }
 
 std::set<locator::tablet_replica> view_building_coordinator::get_replicas_with_tasks() {
@@ -416,7 +390,7 @@ std::vector<utils::UUID> view_building_coordinator::select_tasks_for_replica(loc
     // Select only building tasks and return theirs ids
     auto filter_building_tasks = [] (const std::vector<view_building_task>& tasks) -> std::vector<utils::UUID> {
         return tasks | std::views::filter([] (const view_building_task& t) {
-            return t.type == view_building_task::task_type::build_range && !t.aborted;
+            return t.type == view_building_task::task_type::build_range && t.state == view_building_task::task_state::idle;
         }) | std::views::transform([] (const view_building_task& t) {
             return t.id;
         }) | std::ranges::to<std::vector>();
@@ -430,29 +404,7 @@ std::vector<utils::UUID> view_building_coordinator::select_tasks_for_replica(loc
     }
 
     auto& tablet_map = _db.get_token_metadata().tablets().get_tablet_map(*_vb_sm.building_state.currently_processed_base_table);
-    auto tasks_by_last_token = _vb_sm.building_state.collect_tasks_by_last_token(*_vb_sm.building_state.currently_processed_base_table, replica);
-
-    // Remove completed tasks in `_finished_tasks` from `tasks_by_last_token`
-    auto it = tasks_by_last_token.begin();
-    while (it != tasks_by_last_token.end()) {
-        auto task_it = it->second.begin();
-        while (task_it != it->second.end()) {
-            if (_finished_tasks.at(replica).contains(task_it->id)) {
-                task_it = it->second.erase(task_it);
-            } else {
-                ++task_it;
-            }
-        }
-
-        // Remove the entry from `tasks_by_last_token` if its vector is empty
-        if (it->second.empty()) {
-            it = tasks_by_last_token.erase(it);
-        } else {
-            ++it;
-        }
-    }
-
-    for (auto& [token, tasks]: tasks_by_last_token) {
+    for (auto& [token, tasks]: _vb_sm.building_state.collect_tasks_by_last_token(*_vb_sm.building_state.currently_processed_base_table, replica)) {
         auto tid = tablet_map.get_tablet_id(token);
         if (tablet_map.get_tablet_transition_info(tid)) {
             vbc_logger.debug("Tablet {} on replica {} is in transition.", tid, replica);
@@ -464,7 +416,7 @@ std::vector<utils::UUID> view_building_coordinator::select_tasks_for_replica(loc
             return building_tasks;
         } else {
             return tasks | std::views::filter([] (const view_building_task& t) {
-                return !t.aborted;
+                return t.state == view_building_task::task_state::idle;
             }) | std::views::transform([] (const view_building_task& t) {
                 return t.id;
             }) | std::ranges::to<std::vector>();
@@ -474,21 +426,32 @@ std::vector<utils::UUID> view_building_coordinator::select_tasks_for_replica(loc
     return {};
 }
 
-void view_building_coordinator::start_remote_worker(const locator::tablet_replica& replica, std::vector<utils::UUID> tasks) {
+future<utils::chunked_vector<mutation>> view_building_coordinator::start_tasks(const service::group0_guard& guard, std::vector<utils::UUID> tasks) {
+    vbc_logger.info("Starting tasks {}", tasks);
+
+    utils::chunked_vector<mutation> muts;
+    for (auto& t: tasks) {
+        auto mut = co_await _sys_ks.make_update_view_building_task_state_mutation(guard.write_timestamp(), t, view_building_task::task_state::started);
+        muts.push_back(std::move(mut));
+    }
+    co_return muts;
+}
+
+void view_building_coordinator::attach_to_started_tasks(const locator::tablet_replica& replica, std::vector<utils::UUID> tasks) {
     vbc_logger.debug("Attaching to started tasks {} on replica {}", tasks, replica);
-    shared_future<std::optional<std::vector<utils::UUID>>> work = work_on_tasks(replica, std::move(tasks));
+    shared_future<std::optional<remote_work_results>> work = work_on_tasks(replica, std::move(tasks));
     _remote_work.insert({replica, std::move(work)});
 }
 
-future<std::optional<std::vector<utils::UUID>>> view_building_coordinator::work_on_tasks(locator::tablet_replica replica, std::vector<utils::UUID> tasks) {
+future<std::optional<view_building_coordinator::remote_work_results>> view_building_coordinator::work_on_tasks(locator::tablet_replica replica, std::vector<utils::UUID> tasks) {
     constexpr auto backoff_duration = std::chrono::seconds(1);
     static thread_local logger::rate_limit rate_limit{backoff_duration};
 
-    std::vector<utils::UUID> remote_results;
+    std::vector<view_task_result> remote_results;
     bool rpc_failed = false;
 
     try {
-        remote_results = co_await ser::view_rpc_verbs::send_work_on_view_building_tasks(&_messaging, replica.host, _as, _term, replica.shard, tasks);
+        remote_results = co_await ser::view_rpc_verbs::send_work_on_view_building_tasks(&_messaging, replica.host, _as, tasks);
     } catch (...) {
         vbc_logger.log(log_level::warn, rate_limit, "Work on tasks {} on replica {}, failed with error: {}",
                 tasks, replica, std::current_exception());
@@ -501,14 +464,44 @@ future<std::optional<std::vector<utils::UUID>>> view_building_coordinator::work_
         co_return std::nullopt;
     }
 
-    // In `view_building_coordinator::work_on_view_building()` we made sure that,
-    // each replica has its own entry in the `_finished_tasks`, so now we can just take a shared lock
-    // and insert its of finished tasks to this replica bucket as there is at most one instance of this method for each replica.
-    auto lock = co_await get_shared_lock(_mutex);
-    _finished_tasks.at(replica).insert_range(remote_results);
+    if (tasks.size() != remote_results.size()) {
+        on_internal_error(vbc_logger, fmt::format("Number of tasks ({}) and results ({}) do not match for replica {}", tasks.size(), remote_results.size(), replica));
+    }
 
+    remote_work_results results;
+    for (size_t i = 0; i < tasks.size(); ++i) {
+        results.push_back({tasks[i], remote_results[i]});
+    }
     _vb_sm.event.broadcast();
-    co_return remote_results;
+    co_return results;
+}
+
+// Mark finished task as done (remove them from the table).
+// Retry failed tasks if possible (if failed tasks wasn't aborted).
+future<utils::chunked_vector<mutation>> view_building_coordinator::update_state_after_work_is_done(const service::group0_guard& guard, const locator::tablet_replica& replica, view_building_coordinator::remote_work_results results) {
+    vbc_logger.debug("Got results from replica {}: {}", replica, results);
+
+    utils::chunked_vector<mutation> muts;
+    for (auto& result: results) {
+        vbc_logger.info("Task {} was finished with result: {}", result.first, result.second);
+
+        if (!_vb_sm.building_state.currently_processed_base_table) {
+            continue;
+        }
+
+        // A task can be aborted by deleting it or by setting its state to `ABORTED`.
+        // If the task was aborted by changing the state,
+        // we shouldn't remove it here because it might be needed
+        // to generate updated after tablet operation (migration/resize)
+        // is finished.
+        auto task_opt = _vb_sm.building_state.get_task(*_vb_sm.building_state.currently_processed_base_table, replica, result.first);
+        if (task_opt && task_opt->get().state != view_building_task::task_state::aborted) {
+            // Otherwise, the task was completed successfully and we can remove it.
+            auto delete_mut = co_await _sys_ks.make_remove_view_building_task_mutation(guard.write_timestamp(), result.first);
+            muts.push_back(std::move(delete_mut));
+        }
+    }
+    co_return muts;
 }
 
 future<> view_building_coordinator::stop() {
@@ -538,7 +531,7 @@ void view_building_coordinator::generate_tablet_migration_updates(utils::chunked
     auto create_task_copy_on_pending_replica = [&] (const view_building_task& task) {
         auto new_id = builder.new_id();
         builder.set_type(new_id, task.type)
-                .set_aborted(new_id, false)
+                .set_state(new_id, view_building_task::task_state::idle)
                 .set_base_id(new_id, task.base_id)
                 .set_last_token(new_id, task.last_token)
                 .set_replica(new_id, *trinfo.pending_replica);
@@ -606,7 +599,7 @@ void view_building_coordinator::generate_tablet_resize_updates(utils::chunked_ve
     auto create_task_copy = [&] (const view_building_task& task, dht::token last_token) -> utils::UUID {
         auto new_id = builder.new_id();
         builder.set_type(new_id, task.type)
-                .set_aborted(new_id, false)
+                .set_state(new_id, view_building_task::task_state::idle)
                 .set_base_id(new_id, task.base_id)
                 .set_last_token(new_id, last_token)
                 .set_replica(new_id, task.replica);
@@ -675,7 +668,7 @@ void view_building_coordinator::abort_tasks(utils::chunked_vector<canonical_muta
     auto abort_task_map = [&] (const task_map& task_map) {
         for (auto& [id, _]: task_map) {
             vbc_logger.debug("Aborting task {}", id);
-            builder.set_aborted(id, true);
+            builder.set_state(id, view_building_task::task_state::aborted);
         }
     };
 
@@ -705,7 +698,7 @@ void abort_view_building_tasks(const view_building_state_machine& vb_sm,
         for (auto& [id, task]: task_map) {
             if (task.last_token == last_token) {
                 vbc_logger.debug("Aborting task {}", id);
-                builder.set_aborted(id, true);
+                builder.set_state(id, view_building_task::task_state::aborted);
             }
         }
     };
@@ -721,10 +714,10 @@ void abort_view_building_tasks(const view_building_state_machine& vb_sm,
 
 static void rollback_task_map(view_building_task_mutation_builder& builder, const task_map& task_map) {
     for (auto& [id, task]: task_map) {
-        if (task.aborted) {
+        if (task.state == view_building_task::task_state::aborted) {
             auto new_id = builder.new_id();
             builder.set_type(new_id, task.type)
-                .set_aborted(new_id, false)
+                .set_state(new_id, view_building_task::task_state::idle)
                 .set_base_id(new_id, task.base_id)
                 .set_last_token(new_id, task.last_token)
                 .set_replica(new_id, task.replica);

db/view/view_building_coordinator.hh

@@ -54,9 +54,9 @@ class view_building_coordinator : public service::endpoint_lifecycle_subscriber
     const raft::term_t _term;
     abort_source& _as;
 
-    std::unordered_map<locator::tablet_replica, shared_future<std::optional<std::vector<utils::UUID>>>> _remote_work;
-    shared_mutex _mutex; // guards `_finished_tasks` field
-    std::unordered_map<locator::tablet_replica, std::unordered_set<utils::UUID>> _finished_tasks;
+
+    using remote_work_results = std::vector<std::pair<utils::UUID, db::view::view_task_result>>;
+    std::unordered_map<locator::tablet_replica, shared_future<std::optional<remote_work_results>>> _remote_work;
 
 public:
     view_building_coordinator(replica::database& db, raft::server& raft, service::raft_group0& group0,
@@ -86,11 +86,9 @@ private:
     future<> commit_mutations(service::group0_guard guard, utils::chunked_vector<mutation> mutations, std::string_view description);
     void handle_coordinator_error(std::exception_ptr eptr);
 
-    future<> finished_task_gc_fiber();
-    future<> clean_finished_tasks();
-
     future<std::optional<service::group0_guard>> update_state(service::group0_guard guard);
-    future<> work_on_view_building(service::group0_guard guard);
+    // Returns if any new tasks were started
+    future<bool> work_on_view_building(service::group0_guard guard);
 
     future<> mark_view_build_status_started(const service::group0_guard& guard, table_id view_id, utils::chunked_vector<mutation>& out);
     future<> mark_all_remaining_view_build_statuses_started(const service::group0_guard& guard, table_id base_id, utils::chunked_vector<mutation>& out);
@@ -99,8 +97,10 @@ private:
     std::set<locator::tablet_replica> get_replicas_with_tasks();
     std::vector<utils::UUID> select_tasks_for_replica(locator::tablet_replica replica);
 
-    void start_remote_worker(const locator::tablet_replica& replica, std::vector<utils::UUID> tasks);
-    future<std::optional<std::vector<utils::UUID>>> work_on_tasks(locator::tablet_replica replica, std::vector<utils::UUID> tasks);
+    future<utils::chunked_vector<mutation>> start_tasks(const service::group0_guard& guard, std::vector<utils::UUID> tasks);
+    void attach_to_started_tasks(const locator::tablet_replica& replica, std::vector<utils::UUID> tasks);
+    future<std::optional<remote_work_results>> work_on_tasks(locator::tablet_replica replica, std::vector<utils::UUID> tasks);
+    future<utils::chunked_vector<mutation>> update_state_after_work_is_done(const service::group0_guard& guard, const locator::tablet_replica& replica, remote_work_results results);
 };
 
 void abort_view_building_tasks(const db::view::view_building_state_machine& vb_sm,

db/view/view_building_state.cc

@@ -13,10 +13,10 @@ namespace db {
 
 namespace view {
 
-view_building_task::view_building_task(utils::UUID id, task_type type, bool aborted, table_id base_id, std::optional<table_id> view_id, locator::tablet_replica replica, dht::token last_token)
+view_building_task::view_building_task(utils::UUID id, task_type type, task_state state, table_id base_id, std::optional<table_id> view_id, locator::tablet_replica replica, dht::token last_token)
         : id(id)
         , type(type)
-        , aborted(aborted)
+        , state(state)
         , base_id(base_id)
         , view_id(view_id)
         , replica(replica)
@@ -49,6 +49,30 @@ seastar::sstring task_type_to_sstring(view_building_task::task_type type) {
     }
 }
 
+view_building_task::task_state task_state_from_string(std::string_view str) {
+    if (str == "IDLE") {
+        return view_building_task::task_state::idle;
+    }
+    if (str == "STARTED") {
+        return view_building_task::task_state::started;
+    }
+    if (str == "ABORTED") {
+        return view_building_task::task_state::aborted;
+    }
+    throw std::runtime_error(fmt::format("Unknown view building task state: {}", str));
+}
+
+seastar::sstring task_state_to_sstring(view_building_task::task_state state) {
+    switch (state) {
+    case view_building_task::task_state::idle:
+        return "IDLE";
+    case view_building_task::task_state::started:
+        return "STARTED";
+    case view_building_task::task_state::aborted:
+        return "ABORTED";
+    }
+}
+
 std::optional<std::reference_wrapper<const view_building_task>> view_building_state::get_task(table_id base_id, locator::tablet_replica replica, utils::UUID id) const {
     if (!tasks_state.contains(base_id) || !tasks_state.at(base_id).contains(replica)) {
         return {};
@@ -127,6 +151,46 @@ std::map<dht::token, std::vector<view_building_task>> view_building_state::colle
     return tasks;
 }
 
+// Returns all tasks for `_vb_sm.building_state.currently_processed_base_table` and `replica` with `STARTED` state.
+std::vector<utils::UUID> view_building_state::get_started_tasks(table_id base_table_id, locator::tablet_replica replica) const {   
+    if (!tasks_state.contains(base_table_id) || !tasks_state.at(base_table_id).contains(replica)) {
+        // No tasks for this replica
+        return {};
+    }
+
+    std::vector<view_building_task> tasks;
+    auto& replica_tasks = tasks_state.at(base_table_id).at(replica);
+    for (auto& [_, view_tasks]: replica_tasks.view_tasks) {
+        for (auto& [_, task]: view_tasks) {
+            if (task.state == view_building_task::task_state::started) {
+                tasks.push_back(task);
+            }
+        }
+    }
+    for (auto& [_, task]: replica_tasks.staging_tasks) {
+        if (task.state == view_building_task::task_state::started) {
+            tasks.push_back(task);
+        }
+    }
+
+    // All collected tasks should have the same: type, base_id and last_token,
+    // so they can be executed in the same view_building_worker::batch.
+#ifdef SEASTAR_DEBUG
+    if (!tasks.empty()) {
+        auto& task = tasks.front();
+        for (auto& t: tasks) {
+            SCYLLA_ASSERT(task.type == t.type);
+            SCYLLA_ASSERT(task.base_id == t.base_id);
+            SCYLLA_ASSERT(task.last_token == t.last_token);
+        }
+    }
+#endif
+
+    return tasks | std::views::transform([] (const view_building_task& t) {
+        return t.id;
+    }) | std::ranges::to<std::vector>();
+}
+
 }
 
 }

db/view/view_building_state.hh

@@ -39,17 +39,28 @@ struct view_building_task {
         process_staging,
     };
 
-
+    // When a task is created, it starts with `IDLE` state.
+    // Then, the view building coordinator will decide to do the task and it will
+    // set the state to `STARTED`.
+    // When a task is finished the entry is removed.
+    //
+    // If a task is in progress when a tablet operation (migration/resize) starts,
+    // the task's state is set to `ABORTED`.
+    enum class task_state {
+        idle,
+        started,
+        aborted,
+    };
     utils::UUID id;
     task_type type;
-    bool aborted;
+    task_state state;
 
     table_id base_id;
     std::optional<table_id> view_id; // nullopt when task_type is `process_staging`
     locator::tablet_replica replica;
     dht::token last_token;
 
-    view_building_task(utils::UUID id, task_type type, bool aborted,
+    view_building_task(utils::UUID id, task_type type, task_state state,
             table_id base_id, std::optional<table_id> view_id,
             locator::tablet_replica replica, dht::token last_token);
 };
@@ -81,6 +92,7 @@ struct view_building_state {
     std::vector<std::reference_wrapper<const view_building_task>> get_tasks_for_host(table_id base_id, locator::host_id host) const;
     std::map<dht::token, std::vector<view_building_task>> collect_tasks_by_last_token(table_id base_table_id) const;
     std::map<dht::token, std::vector<view_building_task>> collect_tasks_by_last_token(table_id base_table_id, const locator::tablet_replica& replica) const;
+    std::vector<utils::UUID> get_started_tasks(table_id base_table_id, locator::tablet_replica replica) const;
 };
 
 // Represents global state of tablet-based views.
@@ -101,8 +113,18 @@ struct view_building_state_machine {
     condition_variable event;
 };
 
+struct view_task_result {
+    enum class command_status: uint8_t {
+        success = 0,
+        abort = 1,
+    };
+    db::view::view_task_result::command_status status;
+};
+
 view_building_task::task_type task_type_from_string(std::string_view str);
 seastar::sstring task_type_to_sstring(view_building_task::task_type type);
+view_building_task::task_state task_state_from_string(std::string_view str);
+seastar::sstring task_state_to_sstring(view_building_task::task_state state);
 
 } // namespace view_building
 
@@ -114,11 +136,17 @@ template <> struct fmt::formatter<db::view::view_building_task::task_type> : fmt
     }
 };
 
+template <> struct fmt::formatter<db::view::view_building_task::task_state> : fmt::formatter<string_view> {
+    auto format(db::view::view_building_task::task_state state, fmt::format_context& ctx) const {
+        return fmt::format_to(ctx.out(), "{}", db::view::task_state_to_sstring(state));
+    }
+};
+
 template <> struct fmt::formatter<db::view::view_building_task> : fmt::formatter<string_view> {
     auto format(db::view::view_building_task task, fmt::format_context& ctx) const {
         auto view_id = task.view_id ? fmt::to_string(*task.view_id) : "nullopt";
-        return fmt::format_to(ctx.out(), "view_building_task{{type: {}, aborted: {}, base_id: {}, view_id: {}, last_token: {}}}",
-                task.type, task.aborted, task.base_id, view_id, task.last_token);
+        return fmt::format_to(ctx.out(), "view_building_task{{type: {}, state: {}, base_id: {}, view_id: {}, last_token: {}}}",
+                task.type, task.state, task.base_id, view_id, task.last_token);
     }
 };
 
@@ -133,3 +161,18 @@ template <> struct fmt::formatter<db::view::replica_tasks> : fmt::formatter<stri
         return fmt::format_to(ctx.out(), "{{view_tasks: {}, staging_tasks: {}}}", replica_tasks.view_tasks, replica_tasks.staging_tasks);
     }
 };
+
+template <> struct fmt::formatter<db::view::view_task_result> : fmt::formatter<string_view> {
+    auto format(db::view::view_task_result result, fmt::format_context& ctx) const {
+        std::string_view res;
+        switch (result.status) {
+            case db::view::view_task_result::command_status::success:
+            res = "success";
+            break;
+        case db::view::view_task_result::command_status::abort:
+            res = "abort";
+            break;
+        }
+        return format_to(ctx.out(), "{}", res);
+    }
+};

db/view/view_building_task_mutation_builder.cc

@@ -25,8 +25,8 @@ view_building_task_mutation_builder& view_building_task_mutation_builder::set_ty
     _m.set_clustered_cell(get_ck(id), "type", data_value(task_type_to_sstring(type)), _ts);
     return *this;
 }
-view_building_task_mutation_builder& view_building_task_mutation_builder::set_aborted(utils::UUID id, bool aborted) {
-    _m.set_clustered_cell(get_ck(id), "aborted", data_value(aborted), _ts);
+view_building_task_mutation_builder& view_building_task_mutation_builder::set_state(utils::UUID id, db::view::view_building_task::task_state state) {
+    _m.set_clustered_cell(get_ck(id), "state", data_value(task_state_to_sstring(state)), _ts);
     return *this;
 }
 view_building_task_mutation_builder& view_building_task_mutation_builder::set_base_id(utils::UUID id, table_id base_id) {

db/view/view_building_task_mutation_builder.hh

@@ -32,7 +32,7 @@ public:
     static utils::UUID new_id();
 
     view_building_task_mutation_builder& set_type(utils::UUID id, db::view::view_building_task::task_type type);
-    view_building_task_mutation_builder& set_aborted(utils::UUID id, bool aborted);
+    view_building_task_mutation_builder& set_state(utils::UUID id, db::view::view_building_task::task_state state);
     view_building_task_mutation_builder& set_base_id(utils::UUID id, table_id base_id);
     view_building_task_mutation_builder& set_view_id(utils::UUID id, table_id view_id);
     view_building_task_mutation_builder& set_last_token(utils::UUID id, dht::token last_token);