Since we do no longer support upgrade from versions that do not support
v2 of "view building status" code (building status is managed by raft) we can remove v1 code and upgrade code and make sure we do not boot with old "builder status" version.
v2 version was introduced by 8d25a4d678 which is included in scylla-2025.1.0.
No backport needed since this is code removal.
Closesscylladb/scylladb#29105
* github.com:scylladb/scylladb:
view: drop unused v1 builder code
view: remove upgrade to raft code
Replace the range scan in read_verify_workload() with individual
single-partition queries, using the keys returned by
prepare_write_workload() instead of hard-coding them.
The range scan was previously observed to time out in debug mode after
a hard cluster restart. Single-partition reads are lighter on the
cluster and less likely to time out under load.
The new verification is also stricter: instead of merely checking that
the expected number of rows is returned, it verifies that each written
key is individually readable, catching any data-loss or key-identity
mismatch that the old count-only check would have missed.
This is the second attemp at stabilizing this test, after the recent
854c374ebf. That fix made sure that the
cluster has converged on topology and nodes see each other before running
the verify workload.
Fixes: SCYLLADB-1331
Closesscylladb/scylladb#29313
The supergroup replaces streaming (a.k.a. maintenance as well) group, inherits 200 shares from it and consists of four sub-groups (all have equal shares of 200 withing the new supergroup)
* maintenance_compaction. This group configures `compaction_manager::maintenance_sg()` group. User-triggered compaction runs in it
* backup. This group configures `snapshot_ctl::config::backup_sched_group`. Native backup activity runs there
* maintenance. It's a new "visible" name, everything that was called "maintenance" in the code ran in "streaming" group. Now it will run in "maintenance". The activities include those that don't communicate over RPC (see below why)
* `tablet_allocator::balance_tablets()`
* `sstables_manager::components_reclaim_reload_fiber()`
* `tablet_storage_group_manager::merge_completion_fiber()`
* metrics exporting http server altogether
* streaming. This is purely existing streaming group that just moves under the new supergroup. Everything else that was run there, continues doing so, including
* hints sender
* all view building related components (update generator, builder, workers)
* repair
* stream_manager
* messaging service (except for verb handlers that switch groups)
* join_cluster() activity
* REST API
* ... something else I forgot
The `--maintenance_io_throughput_mb_per_sec` option is introduced. It controls the IO throughput limit applied to the maintenance supergroup. If not set, the `--stream_io_throughput_mb_per_sec` option is used to preserve backward compatibility.
All new sched groups inherit `request_class::maintenance` (however, "backup" seem not to make any requests yet).
Moving more activities from "streaming" into "maintenance" (or its own group) is possible, but one will need to take care of RPC group switching. The thing is that when a client makes an RPC call, the server may switch to one of pre-negotiated scheduling groups. Verbs for existing activities that run in "streaming" group are routed through RPC index that negotiates "streaming" group on the server side. If any of that client code moves to some other group, server will still run the handlers in "streaming" which is not quite expected. That's one of the main reasons why only the selected fibers were moved to their own "maintenance" group. Similar for backup -- this code doesn't use RPC, so it can be moved. Restoring code uses load-and-stream and corresponding RPCs, so it cannot be just moved into its own new group.
Fixes SCYLLADB-351
New feature, not backporting
Closesscylladb/scylladb#28542
* github.com:scylladb/scylladb:
code: Add maintenance/maintenance group
backup: Add maintenance/backup group
compaction: Add maintenance/maintenance_compaction group
main: Introduce maintenance supergroup
main: Move all maintenance sched group into streaming one
database: Use local variable for current_scheduling_group
code: Live-update IO throughputs from main
shared_tombstone_gc_state::update_repair_time() uses copy-on-write
semantics: each call copies the entire per_table_history_maps and the
per-table repair_history_map. repair_service::load_history() called
this once per history entry, making the load O(N²) in both time and
memory.
Introduce batch_update_repair_time() which performs a single
copy-on-write for any number of entries belonging to the same table.
Restructure load_history() to collect entries into batches of up to
1000 and flush each batch in one call, keeping peak memory bounded.
The batch size limit is intentional: the repair history table currently
has no bound on the number of entries and can grow large. Note that
this does not cause a problem in the in-memory history map itself:
entries are coalesced internally and only the latest repair time is
kept per range. The unbounded entry count only makes the batched
update during load expensive.
Fixes: SCYLLADB-104
Closesscylladb/scylladb#29326
When DROP TABLE races with an in-flight DML on a strongly-consistent
table, the node aborts in groups_manager::acquire_server() because the
raft group has already been erased from _raft_groups.
A concurrent DROP TABLE may have already removed the table from database
registries and erased the raft group via schedule_raft_group_deletion.
The schema.table() in create_operation_ctx() might not fail though
because someone might be holding lw_shared_ptr<table>, so that the
table is dropped but the table object is still alive.
Fix by accepting table_id in acquire_server and checking that the table
still exists in the database via find_column_family before looking up
the raft group. If the table has been dropped, find_column_family
throws no_such_column_family instead of the node aborting via
on_internal_error. When the table does exist, acquire_server proceeds
to acquire state.gate; schedule_raft_group_deletion co_awaits
gate::close, so it will wait for the DML operation to complete before
erasing the group.
Fixes SCYLLADB-1450
Add test_drop_table_during_insert that reproduces a crash when DROP TABLE
races with an in-flight INSERT on a strongly-consistent table. The test
uses an error injection to pause INSERT between obtaining the ERM and
calling acquire_server, then drops the table (which destroys the raft
group), then resumes the INSERT. Without a fix, the node aborts in
acquire_server via on_internal_error.
The test is marked as skip until the fix is in place.
Include non-primary key restrictions (e.g. regular column filters) in
the filter JSON sent to the Vector Store service. Previously only
partition key and clustering column restrictions were forwarded, so
filtering on regular columns was silently ignored.
Add get_nonprimary_key_restrictions() getter to statement_restrictions.
Add unit tests for non-primary key equality, range, and bind marker
restrictions in filter_test.
Fixes: SCYLLADB-970
Closesscylladb/scylladb#29019
LDAPRoleManager interpolated usernames directly into ldap_url_template.
That allowed LDAP filter metacharacters to change the query, and URL
metacharacters such as %, ?, and # to change how ldap_url_parse()
split the URL.
Apply two layers of encoding when substituting {USER}:
1. RFC 4515 filter escaping -- neutralises filter operators.
2. URL percent-encoding -- prevents ldap_url_parse from
misinterpreting %-sequences, ? delimiters, or # fragments.
Add validate_query_template() (called from start()) which uses a
sentinel round-trip through ldap_url_parse to reject templates
that place {USER} outside the filter component. Templates that
previously placed {USER} in the host or base DN were silently
accepted; they are now rejected at startup with a descriptive
error.
Change parse_url() to take const sstring& instead of string_view
to enforce the null-termination requirement of ldap_url_parse()
at the type level.
Add regression coverage for %2a, ?, #, and invalid {USER}
placement in the base DN, host, attributes, and extensions.
Update LDAP authorization docs to document the escaping behavior
and the {USER} placement restriction.
Fixes: SCYLLADB-1309
Vector indexes currently store the base table schema version in
`index_version`. That value is name-based, not time-based,
so it does not represent when the index was created.
Store a timeuuid instead and change the relevant interfaces from
`table_schema_version` to `utils::UUID`. This is a prerequisite
for supporting multiple vector indexes on the same column where
the oldest index must be selected deterministically via routing
implemented in Vector Store.
Update the cqlpy tests to check the new semantics directly:
recreating the index changes `index_version`, while ALTER TABLE does not.
For counter updates, use a counter ID that is constructed from the
node's rack instead of the node's host ID.
A rack can have at most two active tablet replicas at a time: a single
normal tablet replica, and during tablet migration there are two active
replicas, the normal and pending replica. Therefore we can have two
unique counter IDs per rack that are reused by all replicas in the rack.
We construct the counter ID from the rack UUID, which is constructed
from the name "dc:rack". The pending replica uses a deterministic
variation of the rack's counter ID by negating it.
This improves the performance and size of counter cells by having less
unique counter IDs and less counter shards in a counter cell.
Previously the number of counter shards was the number of different
host_id's that updated the counter, which can be typically the number of
nodes in the cluster and continue growing indefinitely when nodes are
replaced. with the rack-based counter id the number of counter shards
will be at most twice the number of different racks (including removed
racks, which should not be significant).
Fixes SCYLLADB-356
backport not needed - an enhancement
Closesscylladb/scylladb#28901
* github.com:scylladb/scylladb:
docs/dev: add counters doc
counters: reuse counter IDs by rack
Replace move_to_shard()/move_to_host() with as_bounce()/target_shard()/
target_host() to clarify the interface after bounce was extended to
support cross-node bouncing.
- Add virtual as_bounce() returning const bounce* to the base class
(nullptr by default, overridden in bounce to return this), replacing
the virtual move_to_shard() which conflated bounce detection with
shard access
- Rename move_to_shard() -> target_shard() (now non-virtual, returns
unsigned directly) and move_to_host() -> target_host() on bounce
- Replace dynamic_pointer_cast with static_pointer_cast at call sites
that already checked as_bounce()
- Move forward declarations of message types before the virtual
methods so as_bounce() can reference bounce
Fixes: SCYLLADB-1066
Closesscylladb/scylladb#29367
Motivation
----------
Since strongly consistent tables are based on the concept of Raft
groups, operations on them can get stuck for indefinite amounts of
time. That may be problematic, and so we'd like to implement a way
to cancel those operations at suitable times.
Description of solution
-----------------------
The situations we focus on are the following:
* Timed-out queries
* Leader changes
* Tablet migrations
* Table drops
* Node shutdowns
We handle each of them and provide validation tests.
Implementation strategy
-----------------------
1. Auxiliary commits.
2. Abort operations on timeout.
3. Abort operations on tablet removal.
4. Extend `client_state`.
5. Abort operation on shutdown.
6. Help `state_machine` be aborted as soon as possible.
Tests
-----
We provide tests that validate the correctness of the solution.
The total time spent on `test_strong_consistency.py`
(measured on my local machine, dev mode):
Before:
```
real 0m31.809s
user 1m3.048s
sys 0m21.812s
```
After:
```
real 0m34.523s
user 1m10.307s
sys 0m27.223s
```
The incremental differences in time can be found in the commit messages.
Fixes SCYLLADB-429
Backport: not needed. This is an enhancement to an experimental feature.
Closesscylladb/scylladb#28526
* github.com:scylladb/scylladb:
service: strong_consistency: Abort state_machine::apply when aborting server
service: strong_consistency: Abort ongoing operations when shutting down
service: client_state: Extend with abort_source
service: strong_consistency: Handle abort when removing Raft group
service: strong_consistency: Abort Raft operations on timeout
service: strong_consistency: Use timeout when mutating
service: strong_consistency: Fix indentation
service: strong_consistency: Enclose coordinator methods with try-catch
service: strong_consistency: Crash at unexpected exception
test: cluster: Extract default config & cmdline in test_strong_consistency.py
This reverts commit 8b4a91982b.
Two commits independently added rolling_max_tracker_test to test/boost/CMakeLists.txt:
8b4a919 cmake: add missing rolling_max_tracker_test and symmetric_key_test
f3a91df test/cmake: add missing tests to boost test suite
The second was merged two days after the first. They didn't conflict on
code-level and applied cleanly resulting in a duplicate add_scylla_test()
entries that breaks the CMake build:
CMake Error: add_executable cannot create target
"test_boost_rolling_max_tracker_test" because another target
with the same name already exists.
Remove the duplicate.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Reported-by: Łukasz Paszkowski <lukasz.paszkowski@scylladb.com>
The PR contains more code cleanups, mostly in gossiper. Dropping more gossiper state leaving only NORMAL and SHUTDOWN. All other states are checked against topology state. Those two are left because SHUTDOWN state is propagated through gossiper only and when the node is not in SHUTDOWN it should be in some other state.
No need to backport. Cleanups.
Closesscylladb/scylladb#29129
* https://github.com/scylladb/scylladb:
storage_service: cleanup unused code
storage_service: simplify get_peer_info_for_update
gossiper: send shutdown notifications in parallel
gms: remove unused code
virtual_tables: no need to call gossiper if we already know that the node is in shutdown
gossiper: print node state from raft topology in the logs
gossiper: use is_shutdown instead of code it manually
gossiper: mark endpoint_state(inet_address ip) constructor as explicit
gossiper: remove unused code
gossiper: drop last use of LEFT state and drop the state
gossiper: drop unused STATUS_BOOTSTRAPPING state
gossiper: rename is_dead_state to is_left since this is all that the function checks now.
gossiper: use raft topology state instead of gossiper one when checking node's state
storage_service: drop check_for_endpoint_collision function
storage_service: drop is_first_node function
gossiper: remove unused REMOVED_TOKEN state
gossiper: remove unused advertise_token_removed function
Cassandra's native vector index type is StorageAttachedIndex (SAI). Libraries such as CassIO, LangChain, and LlamaIndex generate `CREATE CUSTOM INDEX` statements using the SAI class name. Previously, ScyllaDB rejected these with "Non-supported custom class".
This PR adds compatibility so that SAI-style CQL statements work on ScyllaDB without modification.
1. **test: enable SAI_VECTOR_ALLOW_CUSTOM_PARAMETERS for Cassandra tests**
Enables the `SAI_VECTOR_ALLOW_CUSTOM_PARAMETERS` Cassandra system property so that `search_beam_width` tests pass against Cassandra 5.0.7.
2. **test: modernize vector index test comments and fix xfail**
Updates test comments from "Reproduces" to "Validates fix for" for clarity, and converts the `test_ann_query_with_pk_restriction` xfail into a stripped-down CREATE INDEX syntax test (removing unused INSERT/SELECT lines). Removes the redundant `test_ann_query_with_non_pk_restriction` test.
3. **cql: add Cassandra SAI (StorageAttachedIndex) compatibility**
Core implementation: the SAI class name is detected and translated to ScyllaDB's native `vector_index`. The fully-qualified class name (`org.apache.cassandra.index.sai.StorageAttachedIndex`) requires exact case; short names (`StorageAttachedIndex`, `sai`) are matched case-insensitively — matching Cassandra's behavior. Non-vector and multi-column SAI targets are rejected with clear errors. Adds `skip_on_scylla_vnodes` fixture, SAI compatibility docs, and the Cassandra compatibility table entry (split into "SAI general" vs "SAI for vector search").
4. **cql: accept source_model option for Cassandra SAI compatibility**
The `source_model` option is a Cassandra SAI property used by Cassandra libraries (e.g., CassIO) to tag vector indexes with the name of the embedding model. ScyllaDB accepts it for compatibility but does not use it — the validator is a no-op lambda. The option is preserved in index metadata and returned in DESCRIBE INDEX output.
- `cql3/statements/create_index_statement.cc`: SAI class detection and rewriting logic
- `index/secondary_index_manager.cc`: case-insensitive class name lookup (lowercasing restored before `classes.find()`)
- `index/vector_index.cc`: `source_model` accepted as a valid option with no-op validator
- `docs/cql/secondary-indexes.rst`: SAI compatibility documentation with `source_model` table row
- `docs/using-scylla/cassandra-compatibility.rst`: SAI entry split into general (not supported) and vector search (supported)
- `test/cqlpy/conftest.py`: `scylla_with_tablets` renamed to `skip_on_scylla_vnodes`
- `test/cqlpy/test_vector_index.py`: SAI tests inlined (no constants), `check_bad_option()` helper for numeric validation, uppercase class name test, merged `source_model` tests with DESCRIBE check
| Backend | Passed | Skipped | Failed |
|--------------------|--------|---------|--------|
| ScyllaDB (dev) | 42 | 0 | 0 |
| Cassandra 5.0.7 | 16 | 26 | 0 |
None: new feature.
Fixes: SCYLLADB-239
Closesscylladb/scylladb#28645
* github.com:scylladb/scylladb:
cql: accept source_model option and show options in DESCRIBE
cql: add Cassandra SAI (StorageAttachedIndex) compatibility
test: modernize vector index test comments and fix xfail
test: enable SAI_VECTOR_ALLOW_CUSTOM_PARAMETERS for Cassandra tests
This metric is used to catch execution of scans which go via row
cache, which can have bad effect on performance.
Since f344bd0aaa, aggreagte queries go
via new statement class: parallelized_select_statement. This class
inherits from select_statement directly rather than from
primary_key_select_statement. The range scan detection logic
(_range_scan, _range_scan_no_bypass_cache) was only in
primary_key_select_statement's constructor, so parallelized queries
were not counted in select_partition_range_scan and
select_partition_range_scan_no_bypass_cache metrics.
Fix by moving the range scan detection into select_statement's
constructor, so that all subclasses get it.
get_node_metrics() in test/cluster/dtest/tools/metrics.py used
re.search(metric_name, metric) to match Prometheus metric lines. The
metric name select_partition_range_scan is a substring of
select_partition_range_scan_no_bypass_cache. So when querying for
select_partition_range_scan, the regex matched both Prometheus lines:
scylla_cql_select_partition_range_scan{shard="0",...} 1
scylla_cql_select_partition_range_scan_no_bypass_cache{shard="0",...} 1
And because the code does metrics_res[metric_name] += val, it summed
both values, making it look like the counter was incremented
by 2 when it was actually incremented by 1. The fix appends r"[\s{]"
to the regex so the metric name must be followed by { (labels) or
whitespace (value), preventing substring matches.
Add system.tablets to the set of system resources that can be
accessed with the VECTOR_SEARCH_INDEXING permission.
Fixes: VECTOR-605
Closesscylladb/scylladb#29397
Remove the create_ks_and_cf() helper function and its now-unused import
of format_tuples(). All callers have been converted to use the new
async patterns with new_test_keyspace() and cql.run_async().
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Replace all 6 calls to create_ks_and_cf() with new async patterns:
- Use new_test_keyspace() context manager for keyspace creation
- Use cql.run_async() for CREATE TABLE statement
- Use asyncio.gather() with cql.run_async() for data insertion
The test_restore_with_non_existing_sstable only needs the ks:table
structure to exist; it doesn't use the pre-populated data.
This change makes the code more explicit and maintains proper async
semantics throughout.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Add if-True blocks to wrap code that uses create_ks_and_cf() in all 6
test functions. This is a mechanical change to set up the next step
where the helper will be replaced with new async patterns. All code
after the create_ks_and_cf() call until the end of each test is now
indented under the if-True block.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Accept the Cassandra SAI 'source_model' option for vector indexes.
This option is used by Cassandra libraries (e.g., CassIO, LangChain)
to tag vector indexes with the name of the embedding model that
produced the vectors.
ScyllaDB does not use the source_model value but stores it and
includes it in the DESCRIBE INDEX output for Cassandra compatibility.
Additionally, extend vector_index::describe() to emit a
WITH OPTIONS = {...} clause containing all user-provided index options
(filtering out system keys: target, class_name, index_version).
This makes options like similarity_function, source_model, etc.
visible in DESCRIBE output.
Libraries such as CassIO, LangChain, and LlamaIndex create vector
indexes using Cassandra's StorageAttachedIndex (SAI) class name.
This commit lets ScyllaDB accept these statements without modification.
When a CREATE CUSTOM INDEX statement specifies an SAI class name on a
vector column, ScyllaDB automatically rewrites it to the native
vector_index implementation. Accepted class names (case-insensitive):
- org.apache.cassandra.index.sai.StorageAttachedIndex
- StorageAttachedIndex
- sai
SAI on non-vector columns is rejected with a clear error directing
users to a secondary index instead.
The SAI detection and rewriting logic is extracted into a dedicated
static function (maybe_rewrite_sai_to_vector_index) to keep the
already-long validate_while_executing method manageable.
Multi-column (local index) targets and nonexistent columns are
skipped with continue — the former are treated as filtering columns
by vector_index::check_target(), and the latter are caught later by
vector_index::validate().
Tests that exercise features common to both backends (basic creation,
similarity_function, IF NOT EXISTS, bad options, etc.) now use the
SAI class name with the skip_on_scylla_vnodes fixture so they run
against both ScyllaDB and Cassandra. ScyllaDB-specific tests continue
to use USING 'vector_index' with scylla_only.
- Change 'Reproduces' to 'Validates fix for' in test comments to
reflect that the referenced issues are already fixed.
- Condense the VECTOR-179 comment to two lines.
- Replace the xfailed test_ann_query_with_restriction_works_only_on_pk
with a focused test (test_ann_query_with_pk_restriction) that creates
a vector index on a table with a PK column restriction, validating
the VECTOR-374 fix.
Every time someone modifies the build system — adding a source file, changing a compilation flag, or wiring a new test — the change tends to land in only one of our two build systems (configure.py or CMake). Over time this causes three classes of problems:
1. **CMake stops compiling entirely.** Missing defines, wrong sanitizer flags, or misplaced subdirectory ordering cause hard build failures that are only discovered when someone tries to use CMake (e.g. for IDE integration).
2. **Missing build targets.** Tests or binaries present in configure.py are never added to CMake, so `cmake --build` silently skips them. This PR fixes several such cases (e.g. `symmetric_key_test`, `auth_cache_test`, `sstable_tablet_streaming`).
3. **Missing compilation units in targets.** A `.cc` file is added to a test binary in one system but not the other, causing link errors or silently omitted test coverage.
To fix the existing drift and prevent future divergence, this series:
**Adds a build-system comparison script**
(`scripts/compare_build_systems.py`) that configures both systems into a temporary directory, parses their generated `build.ninja` files, and compares per-file compilation flags, link target sets, and per-target libraries. configure.py is treated as the baseline; CMake must match it. The script supports a `--ci` mode suitable for gating PRs that touch
build files.
**Fixes all current mismatches** found by the script:
- Mode flag alignment in `mode.common.cmake` and `mode.Coverage.cmake`
(sanitizer flags, `-fno-lto`, stack-usage warnings, coverage defines).
- Global define alignment (`SEASTAR_NO_EXCEPTION_HACK`, `XXH_PRIVATE_API`,
`BOOST_ALL_DYN_LINK`, `SEASTAR_TESTING_MAIN` placement).
- Seastar build configuration (shared vs static per mode, coverage
sanitizer link options).
- Abseil sanitizer flags (`-fno-sanitize=vptr`).
- Missing test targets in `test/boost/CMakeLists.txt`.
- Redundant per-test flags now covered by global settings.
- Lua library resolution via a custom `cmake/FindLua.cmake` using
pkg-config, matching configure.py's approach.
**Adds documentation** (`docs/dev/compare-build-systems.md`) describing how to run the script and interpret its output.
No backport needed — this is build infrastructure improvement only.
Closesscylladb/scylladb#29273
* github.com:scylladb/scylladb:
scripts: remove lua library rename workaround from comparison script
cmake: add custom FindLua using pkg-config to match configure.py
test/cmake: add missing tests to boost test suite
test/cmake: remove per-test LTO disable
cmake: add BOOST_ALL_DYN_LINK and strip per-component defines
cmake: move SEASTAR_TESTING_MAIN after seastar and abseil subdirs
cmake: add -fno-sanitize=vptr for abseil sanitizer flags
cmake: align Seastar build configuration with configure.py
cmake: align global compile defines and options with configure.py
cmake: fix Coverage mode in mode.Coverage.cmake
cmake: align mode.common.cmake flags with configure.py
configure.py: add sstable_tablet_streaming to combined_tests
docs: add compare-build-systems.md
scripts: add compare_build_systems.py to compare ninja build files
Add .set_skip_when_empty() to all error-path metrics in the tracing
module. Tracing itself is not a commonly used feature, making all of
these metrics almost always zero:
Tier 1 (very rare - corruption/schema issues):
- tracing_keyspace_helper::bad_column_family_errors: tracing schema
missing or incompatible, should never happen post-bootstrap
- tracing::trace_errors: internal error building trace parameters
Tier 2 (overload - tracing backend saturated):
- tracing::dropped_sessions: too many pending sessions
- tracing::dropped_records: too many pending records
Tier 3 (general tracing write errors):
- tracing_keyspace_helper::tracing_errors: errors during writes to
system_traces keyspace
Since tracing is an opt-in feature that most deployments rarely use,
all five metrics are almost always zero and create unnecessary
reporting overhead.
AI-Assisted: yes
Signed-off-by: Yaniv Kaul <yaniv.kaul@scylladb.com>
Closesscylladb/scylladb#29346
Add a documentation of the counters feature implementation in
docs/dev/counters.md.
The documentation is taken from the wiki and updated according to the
current state of the code - legacy details are removed, and a section
about the counter id is added.
For counter updates, use a counter ID that is constructed from the
node's rack instead of the node's host ID.
A rack can have at most two active tablet replicas at a time: a single
normal tablet replica, and during tablet migration there are two active
replicas, the normal and pending replica. Therefore we can have two
unique counter IDs per rack that are reused by all replicas in the rack.
We construct the counter ID from the rack UUID, which is constructed
from the name "dc:rack". The pending replica uses a deterministic
variation of the rack's counter ID by negating it.
This improves the performance and size of counter cells by having less
unique counter IDs and less counter shards in a counter cell.
Previously the number of counter shards was the number of different
host_id's that updated the counter, which can be typically the number of
nodes in the cluster and continue growing indefinitely when nodes are
replaced. with the rack-based counter id the number of counter shards
will be at most twice the number of different racks (including removed
racks, which should not be significant).
Fixes SCYLLADB-356
Add .set_skip_when_empty() to four metrics in replica/database.cc that
are only incremented on very rare error paths and are almost always zero:
- database::dropped_view_updates: view updates dropped due to overload.
NOTE: this metric appears to never be incremented in the current
codebase and may be a candidate for removal.
- database::multishard_query_failed_reader_stops: documented as a 'hard
badness counter' that should always be zero. NOTE: no increment site
was found in the current codebase; may be a candidate for removal.
- database::multishard_query_failed_reader_saves: documented as a 'hard
badness counter' that should always be zero.
- database::total_writes_rejected_due_to_out_of_space_prevention: only
fires when disk utilization is critical and user table writes are
disabled, a very rare operational state.
These metrics create unnecessary reporting overhead when they are
perpetually zero. set_skip_when_empty() suppresses them from metrics
output until they become non-zero.
AI-Assisted: yes
Signed-off-by: Yaniv Kaul <yaniv.kaul@scylladb.com>
Closesscylladb/scylladb#29345
After obtaining the CQL response, check if its actual size exceeds the initially acquired memory permit. If so, acquire additional semaphore units and adopt them into the permit, ensuring accurate memory accounting for large responses.
Additionally, move the permit into a .then() continuation so that the semaphore units are kept alive until write_message finishes, preventing premature release of memory permit. This is especially important with slow networks and big responses when buffers can accumulate and deplete a node's memory.
Fixes: https://scylladb.atlassian.net/browse/SCYLLADB-1306
Related https://scylladb.atlassian.net/browse/SCYLLADB-740
Backport: all supported versions
Closesscylladb/scylladb#29288
* github.com:scylladb/scylladb:
transport: add per-service-level pending response memory metric
transport: hold memory permit until response write completes
transport: account for response size exceeding initial memory estimate
Add .set_skip_when_empty() to four metrics in the db module that are
only incremented on very rare error paths and are almost always zero:
- cache::pinned_dirty_memory_overload: described as 'should sit
constantly at 0, nonzero is indicative of a bug'
- corrupt_data::entries_reported: only fires on actual data corruption
- hints::corrupted_files: only fires on on-disk hint file corruption
- rate_limiter::failed_allocations: only fires when the rate limiter
hash table is completely full and gives up allocating, requiring
extreme cardinality pressure
These metrics create unnecessary reporting overhead when they are
perpetually zero. set_skip_when_empty() suppresses them from metrics
output until they become non-zero.
AI-Assisted: yes
Signed-off-by: Yaniv Kaul <yaniv.kaul@scylladb.com>
Closesscylladb/scylladb#29344
get_live_members function called is_shutdown which inet_address
argument, which caused temporary endpoint_state to be created. Fix
it by prohibiting implicit conversion and calling the correct
is_shutdown function instead.
The decommission sets left gossiper state only to prevent shutdown
notification be issued by the node during shutdown. Since the
notification code now checks the state in raft topology this is no
longer needed.
