When a malformed sstable error occurs, it is usually caused by actual sstable corruption — a cosmic ray, a bad disk write, etc. However, it can also be caused by memory corruption, where a data structure in memory happens to be read as sstable data. In the latter case, having a coredump of the process at the moment of the error is invaluable for post-mortem debugging, since the exception throwing/catching machinery destroys the stack frames that would point to the corruption site.
This patch series introduces `--abort-on-malformed-sstable-error`, a new command-line option (with `LiveUpdate` support) that, when set, causes the server to call `std::abort()` instead of throwing an exception whenever any sstable parse error is detected. This covers all code paths:
- Direct `throw malformed_sstable_exception(...)` sites (migrated to `throw_malformed_sstable_exception()`)
- Direct `throw bufsize_mismatch_exception(...)` sites (migrated to `throw_bufsize_mismatch_exception()`)
- `parse_assert()` failures (via `on_parse_error()`)
- BTI parse errors (via `on_bti_parse_error()`)
The implementation places the flag and helper functions in `sstables/sstables.cc`, next to the existing `on_parse_error()` / `on_bti_parse_error()` infrastructure.
The flag defaults to `false`, preserving current behaviour. It is intended to be enabled temporarily when investigating suspected memory corruption.
**Commit breakdown:**
1. Infrastructure: flag, getter/setter, and throw helpers in `sstables/sstables.cc`; config option wired up in `main.cc`
2. `on_parse_error()` and `on_bti_parse_error()` check the new flag
3. All ~50 `throw malformed_sstable_exception(...)` sites migrated
4. Both `throw bufsize_mismatch_exception(...)` sites migrated
Refs: SCYLLADB-1087
Backport: new feature, no backport
Closesscylladb/scylladb#29324
* github.com:scylladb/scylladb:
sstables: migrate all bufsize_mismatch_exception throw sites to throw_bufsize_mismatch_exception()
sstables: migrate all malformed_sstable_exception throw sites to throw_malformed_sstable_exception()
sstables: make on_parse_error() and on_bti_parse_error() respect --abort-on-malformed-sstable-error
sstables: disable abort-on-malformed-sstable-error in tests that corrupt sstables on purpose
sstables: introduce --abort-on-malformed-sstable-error infrastructure
sstables: refactor parse_path() to return std::expected<> instead of throwing
Add a node_owner column (locator::host_id) to system.sstables and make it part of the partition key, so the primary key becomesv PRIMARY KEY ((table_id, node_owner), generation).
This is the first step toward moving the sstables registry into system_distributed: once distributed, each node's startup scan must read only the rows it owns, which requires the owning node to be part of the partition key. Partitioning by (table_id, node_owner) turns that scan into a single-partition read of exactly the local node's rows.
Fixes: https://scylladb.atlassian.net/browse/SCYLLADB-1562
No need to backport this, keyspace over object storage is experimental feature
Closesscylladb/scylladb#29659
* github.com:scylladb/scylladb:
db, sstables: add node_owner to sstables registry primary key
db, sstables: rename sstables registry column owner to table_id
Add scoped_no_abort_on_malformed_sstable_error RAII guard (modeled after
seastar::testing::scoped_no_abort_on_internal_error) and use it in all
tests that intentionally corrupt sstables and expect
malformed_sstable_exception to be thrown rather than the process aborting.
Parallelize SSTable creation using parallel_for_each. The file
count is made a parameter with a default of 64, allowing future
S3/GCS variants to use a smaller count if needed.
Parallelize SSTable creation using parallel_for_each and reduce
the SSTable count from 256 to 64 for S3/GCS variants. The local
test variant retains the original 256 count.
Parallelize SSTable creation across all sub-tests using
parallel_for_each and reduce the SSTable count from 256 to 64 for
S3/GCS variants.
Re-enable the S3 test variant that was previously disabled due to
taking 4+ minutes. With parallel creation and reduced count, the
test now completes in a reasonable time.
Pre-extract mutation pairs and use parallel_for_each with
make_sstable_containing_async to create SSTables concurrently
instead of sequentially. The post-creation loop still runs serially
to collect token ranges and generations.
Pre-extract mutation pairs and use parallel_for_each with
make_sstable_containing_async to create SSTables concurrently
instead of sequentially. The post-creation loop still runs serially
to collect token ranges and generations that depend on SSTable order.
Use parallel_for_each with make_sstable_containing_async to create
SSTables concurrently instead of sequentially, reducing wall-clock
time on remote storage backends (S3/GCS).
Use parallel_for_each with make_sstable_containing_async to create
SSTables concurrently instead of sequentially, reducing wall-clock
time on remote storage backends (S3/GCS).
The original make_memtable used seastar::thread::yield() for
preemption, which required all callers to run inside a
seastar::thread context. This prevented the utilities from being
used directly in coroutines or parallel_for_each lambdas.
Make the primary functions — make_memtable, make_sstable_containing,
and verify_mutation — return future<> directly. Callers now .get()
explicitly when in seastar::thread context, or co_await when in
a coroutine.
make_memtable now uses coroutine::maybe_yield() instead of
seastar::thread::yield(). verify_mutation is converted to
coroutines as well.
Requested in:
https://github.com/scylladb/scylladb/pull/29416#pullrequestreview-4112296282
Add a node_owner column (locator::host_id) to system.sstables and
make it part of the partition key, so the primary key becomes
PRIMARY KEY ((table_id, node_owner), generation).
This is the first step toward moving the sstables registry into
system_distributed: once distributed, each node's startup scan
must read only the rows it owns, which requires the owning node
to be part of the partition key. Partitioning by (table_id,
node_owner) turns that scan into a single-partition read of
exactly the local node's rows.
The new column is populated via sstables_manager::get_local_host_id().
No backward compatibility is preserved; the feature is experimental
and gated by keyspace-storage-options.
Now that object_storage_base::clone is implemented,
remove the early-return skips and re-enable the
sstable_clone_leaving_unsealed_dest_sstable tests for
both S3 and GCS storage backends.
Replace direct filesystem checks (file_exists) with the
storage-agnostic exists() method in unsealed_sstable_compaction,
sstable_clone_leaving_unsealed_dest_sstable, and
failure_when_adding_new_sstable tests, making them compatible
with object-storage backends (S3, GCS).
Start using `table_for_tests::make_default_schema` so test tables are
created with a real schema. This is required for object-storage
backends, which cannot operate correctly without proper schema
initialization.
Switch tests to use sstable member functions for file manipulation
instead of opening files directly on the filesystem. This affects the
helpers that emulate sstable corruption: we now overwrite the entire
component file rather than just the first few kilobytes, which is
sufficient for producing a corrupted sstable.
Generalize corrupt_sstable() and scrub_validate_corrupted_file() to
accept a component_type parameter, defaulting to Data, so they can be
reused for corrupting other components.
This pull request adds support for calculation and storing CRC32 digests for all SSTable components.
This change replaces plain file_writer with crc32_digest_file_writer for all SSTable components that should be checksummed. The resulting component digests are stored in the sstable structure
and later persisted to disk as part of the Scylla metadata component during writer::consume_end_of_stream.
Several test cases where introduced to verify expected behaviour.
Additionally, this PR adds new rewrite component mechanism for safe sstable component rewriting.
Previously, rewriting an sstable component (e.g., via rewrite_statistics) created a temporary file that was renamed to the final name after sealing. This allowed crash recovery by simply removing the temporary file on startup.
However, with component digests stored in scylla_metadata (#20100),
replacing a component like Statistics requires atomically updating both the component
and scylla_metadata with the new digest - impossible with POSIX rename.
The new mechanism creates a clone sstable with a fresh generation:
- Hard-links all components from the source except the component being rewritten and scylla_metadata
- Copies original sstable components pointer and recognized components from the source
- Invokes a modifier callback to adjust the new sstable before rewriting
- Writes the modified component along with updated scylla_metadata containing the new digest
- Seals the new sstable with a temporary TOC
- Replaces the old sstable atomically, the same way as it is done in compaction
This is built on the rewrite_sstables compaction framework to support batch operations (e.g., following incremental repair).
In case of any failure durning the whole process, sstable will be automatically deleted on the node startup due to
temporary toc persistence.
Backport is not required, it is a new feature
Fixes https://github.com/scylladb/scylladb/issues/20100, https://github.com/scylladb/scylladb/issues/27453Closesscylladb/scylladb#28338
* github.com:scylladb/scylladb:
docs: document components_digests subcomponent and trailing digest in Scylla.db
sstable_compaction_test: Add tests for perform_component_rewrite
sstable_test: add verification testcases of SSTable components digests persistance
sstables: store digest of all sstable components in scylla metadata
sstables: replace rewrite_statistics with new rewrite component mechanism
sstables: add new rewrite component mechanism for safe sstable component rewriting
compaction: add compaction_group_view method to specify sstable version
sstables: add null_data_sink and serialized_checksum for checksum-only calculation
sstables: extract default write open flags into a constant
sstables: Add write_simple_with_digest for component checksumming
sstables: Extract file writer closing logic into separate methods
sstables: Implement CRC32 digest-only writer
Add two test cases to verify the correctness of the perform_component_rewrite
functionality:
- test_perform_component_rewrite_single_sstable: Tests rewriting the Statistics
component of a single sstable
- test_perform_component_rewrite_multiple_sstables: Tests rewriting 5 out of 10
sstables
Since the function must only be used on new sstables, it should
be renamed to something describing its usage should be restricted.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
This is crucial for splitting before sealing the sstable produced by
repair. This way, unsplit sstables won't be left on disk sealed.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Every table and sstable set keeps track of the total file size
of contained sstables.
Due to a feature request, we also want to keep track of the hypothetical
file size if Data files were uncompressed, to add a metric that
shows the compression ratio of sstables.
We achieve this by replacing the relevant `uint_64 bytes_on_disk`
counters everywhere with a struct that contains both the actual
(post-compression) size and the hypothetical pre-compression size.
This patch isn't supposed to change any observable behavior.
In the next patch, we will use these changes to add a new metric.
This PR introduces support for a new scrub option: `--drop-unfixable-sstables`, which enables the dropping of corrupted SSTables during scrub only in segregate mode. The patch includes implementation, validation, and set of tests to ensure correct behavior and error handling.
Fixes#19060
Backport is not required, it is a new feature
Closesscylladb/scylladb#26579
* github.com:scylladb/scylladb:
sstable_compaction_test: add segregate mode tests for drop-unfixable-sstables option
test/nodetool: add scrub drop-unfixable-sstables option testcase
scrub: add support for dropping unfixable sstables in segregate mode
Added a new test case, sstable_scrub_segregate_mode_drop_unfixable_sstables_test,
which verifies that when the drop-unfixable-sstables flag is enabled in segregate
mode, corrupted SSTables are correctly dropped.
This patch adds a new flag `drop-unfixable-sstables` to the scrub operation
in segregate mode, allowing to automatically drop SSTables that
cannot be fixed during scrub. It also includes API support of the 'drop_unfixable_sstables'
paramater and validation to ensure this flag is not enabled in other modes rather than segragate.
Integrates GCP object storage as a working storage backend for scylla sstables as well as backup storage.
Adds an abstraction layer (atm very heavily designed around the s3 client interface and usage) to allow the "storage" etc layers of sstable management to pick transparently between "s3" and "gs" providers.
This modifies the scylla config such that endpoints can optionally (through a "type" param) ref a GS backend.
Similarly with storage_options.
Also adds some IO wrapping primitives to make it more feasible to place some logic at a mid level of the implementation stack (such as making networked storage files, ranged reading etc).
Test s3 fixture is replaced (where appropriate) with an `object_storage` fixture that multiplexes the test across both backends.
Unit tests are duplicated and for the GS versions use a boost test fixture for GCS, default local fake.
Fixes#25359Fixes#26453Closesscylladb/scylladb#26186
* github.com:scylladb/scylladb:
docs::dev::object_storage: Add some initial info on GS storage
docs/dev: Add mention of (nested) docker usage in testing.md
sstables::object_storage_client: Forward memory limit semaphore to GS instance
utils::gcp::object_storage: Add optional memory limits to up/download
sstables::object_storage_client: Add multi-upload support for GS
utils::gcp::storage: Add merge objects operation
test_backup/test_basic: Make tests multiplex both s3 and gs backends
test::cluster::conftest: Add support for multiple object storage backends
boost::gcs_storage_test: reindent
boost::gcs_storage_test: Convert to use fixture
tests::boost: Add GS object storage cases to mirror S3 ones
tests::lib::gcs_fixture: Add a reusable test fixture for real/fake GS/GCS
tests::lib::test_utils: Add overloads/helpers for reading and (temp) writing env
sstables::object_storage_client: Add google storage implementation
test_services: Allow testing with GS object storage parameters
utils::gcp::gcp_credentials: Add option to create uninitialized credentials
utils::gcp::object_storage: Make create_download_source return seekable_data_source
utils::gcp::object_storage: Add defensive copies of string_view params
utils::gcp::object_storage: Add missing retry backoff increate
utils::gcp::object_storage: Add timestamp to object listing
utils::gcp::object_storage: Add paging support to list_objects
object_storage_client: Add object_name wrapper type
utils::gcp::object_storage: Add optional abort_source
utils::rest::client: Add abort_source support
sstables: Use object_storage_client for remote storage
sstables::object_storage_client: Add abstraction layer for OS cliens (s3 initial)
s3::upload_progress: Promote to general util type
storage_options: Abstract s3 to "object_storage" and add gs as option
sstables::file_io_extension: Change "creator" callback to just data_source
utils::io-wrappers: Add ranged data_source
utils::io-wrappers: Add file wrapper type for seekable_source
utils::seekable_source: Add a seekable IO source type
object_storage_endpoint_param: Add gs storage as option
config: break out object_storage_endpoint_param preparing for multi storage
The `compaction_strategy_state` class holds strategy specific state via
a `std::variant` containing different state types. When a compaction
strategy performs compaction, it retrieves a reference to its state from
the `compaction_strategy_state` object. If the table's compaction
strategy is ALTERed while a compaction is in progress, the
`compaction_strategy_state` object gets replaced, destroying the old
state. This leaves the ongoing compaction holding a dangling reference,
resulting in a use after free.
Fix this by using `seastar::shared_ptr` for the state variant
alternatives(`leveled_compaction_strategy_state_ptr` and
`time_window_compaction_strategy_state_ptr`). The compaction strategies
now hold a copy of the shared_ptr, ensuring the state remains valid for
the duration of the compaction even if the strategy is altered.
The `compaction_strategy_state` itself is still passed by reference and
only the variant alternatives use shared_ptrs. This allows ongoing
compactions to retain ownership of the state independently of the
wrapper's lifetime.
Fixes#25913
Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
This is yet another part in the BTI index project.
Overarching issue: https://github.com/scylladb/scylladb/issues/19191
Previous part: https://github.com/scylladb/scylladb/pull/25626
Next parts: make `ms` the default. Then, general tweaks and improvements. Later, potentially a full `da` format implementation.
This patch series introduces a new, Scylla-only sstable format version `ms`, which is like `me`, but with the index components (Summary.db and Index.db) replaced with BTI index components (Partitions.db and Rows.db), as they are in Cassandra 5.0's `da` format version.
(Eventually we want to just implement `da`, but there are several other changes (unrelated to the index files) between `me` and `da`. By adding this `ms` as an intermediate step we can adapt the new index formats without dragging all the other changes into the mix (and raising the risk of regressions, which is already high)).
The high-level structure of the PR is:
1. Introduce new component types — `Partitions` and `Rows`.
2. Teach `class sstable` to open them when they exist.
3. Teach the sstable writer how to write index data to them.
4. Teach `class sstable` and unit tests how to deal with sstables that have no `Index` or `Summary` (but have `Partitions` and `Rows` instead).
5. Introduce the new sstable version `ms`, specify that it has `Partitions` and `Rows` instead of `Index` and `Summary`.
6. Prepare unit tests for the appearance of `ms`.
7. Enable `ms` in unit tests.
8. Make `ms` enablable via db::config (with a silent fall back to `me` until the new `MS_SSTABLE_FORMAT` cluster feature is enabled).
9. Prepare integration tests for the appearance of `ms`.
10. Enable both `ms` and `me` in tests where we want both versions to be tested.
This series doesn't make `ms` the default yet, because that requires teaching Scylla Manager and a few dtests about the new format first. It can be enabled by setting `sstable_format: ms` in the config.
Per a review request, here is an example from `perf_fast_forward`, demonstrating some motivation for a new format. (Although not the main one. The main motivations are getting rid of restrictions on the RAM:disk ratio, and index read throughput for datasets with tiny partitions). The dataset was populated with `build/release/scylla perf-fast-forward --smp=1 --sstable-format=$VERSION --data-directory=data.$VERSION --column-index-size-in-kb=1 --populate --random-seed=0`.
This test involves a partition with 1000000 clustering rows (with 32-bit keys and 100-byte values) and ~500 index blocks, and queries a few particular rows from the partition. Since the branching factor for the BIG promoted index is 2 (it's a binary search), the lookup involves ~11.2 sequential page reads per row. The BTI format has a more reasonable branching factor, so it involves ~2.3 page reads per row.
`build/release/scylla perf-fast-forward --smp=1 --data-directory=perf_fast_forward_data/me --run-tests=large-partition-select-few-rows`:
```
offset stride rows iterations avg aio aio (KiB)
500000 1 1 70 18.0 18 128
500001 1 1 647 19.0 19 132
0 1000000 1 748 15.0 15 116
0 500000 2 372 29.0 29 284
0 250000 4 227 56.0 56 504
0 125000 8 116 106.0 106 928
0 62500 16 67 195.0 195 1732
```
`build/release/scylla perf-fast-forward --smp=1 --data-directory=perf_fast_forward_data/ms --run-tests=large-partition-select-few-rows`:
```
offset stride rows iterations avg aio aio (KiB)
500000 1 1 51 5.1 5 20
500001 1 1 64 5.3 5 20
0 1000000 1 679 4.0 4 16
0 500000 2 492 8.0 8 88
0 250000 4 804 16.0 16 232
0 125000 8 409 31.0 31 516
0 62500 16 97 54.0 54 1056
```
Index file size comparison for the default `perf_fast_forward` tables with `--random-seed=0`:
Large partition table (dominated by intra-partition index): 2.4 MB with `me`, 732 kB with `ms`.
For the small partitions table (dominated by inter-partition index): 11 MB with `me`, 8.4 MB with `ms`.
External tests:
I ran SCT test `longevity-mv-si-4days-streaming-test` test on 6 nodes with 30 shards each for 8 hours. No anomalies were observed.
New functionality, no backport needed.
Closesscylladb/scylladb#26215
* github.com:scylladb/scylladb:
test/boost/bloom_filter_test: add test_rebuild_from_temporary_hashes
test/cluster: add test_bti_index.py
test: prepare bypass_cache_test.py for `ms` sstables
sstables/trie/bti_index_reader: add a failure injection in advance_lower_and_check_if_present
test/cqlpy/test_sstable_validation.py: prepare the test for `ms` sstables
tools/scylla-sstable: add `--sstable-version=?` to `scylla sstable write`
db/config: expose "ms" format to the users via database config
test: in Python tests, prepare some sstable filename regexes for `ms`
sstables: add `ms` to `all_sstable_versions`
test/boost/sstable_3_x_test: add `ms` sstables to multi-version tests
test/lib/index_reader_assertions: skip some row index checks for BTI indexes
test/boost/sstable_inexact_index_test: explicitly use a `me` sstable
test/boost/sstable_datafile_test: skip test_broken_promoted_index_is_skipped for `ms` sstables
test/resource: add `ms` sample sstable files for relevant tests
test/boost/sstable_compaction_test: prepare for `ms` sstables.
test/boost/index_reader_test: prepare for `ms` sstables
test/boost/bloom_filter_tests: prepare for `ms` sstables
test/boost/sstable_datafile_test: prepare for `ms` sstables
test/boost/sstable_test: prepare for `ms` sstables.
sstables: introduce `ms` sstable format version
tools/scylla-sstable: default to "preferred" sstable version, not "highest"
sstables/mx/reader: use the same hashed_key for the bloom filter and the index reader
sstables/trie/bti_index_reader: allow the caller to passing a precalculated murmur hash
sstables/trie/bti_partition_index_writer: in add(), get the key hash from the caller
sstables/mx: make Index and Summary components optional
sstables: open Partitions.db early when it's needed to populate key range for sharding metadata
sstables: adapt sstable::set_first_and_last_keys to sstables without Summary
sstables: implement an alternative way to rebuild bloom filters for sstables without Index
utils/bloom_filter: add `add(const hashed_key&)`
sstables: adapt estimated_keys_for_range to sstables without Summary
sstables: make `sstable::estimated_keys_for_range` asynchronous
sstables/sstable: compute get_estimated_key_count() from Statistics instead of Summary
replica/database: add table::estimated_partitions_in_range()
sstables/mx: implement sstable::has_partition_key using a regular read
sstables: use BTI index for queries, when present and enabled
sstables/mx/writer: populate BTI index files
sstables: create and open BTI index files, when enabled
sstables: introduce Partition and Rows component types
sstables/mx/writer: make `_pi_write_m.partition_tombstone` a `sstables::deletion_time`
sstables/exceptions.hh still hosts some compaction specific exception
types. Move them over to the new compaction/exceptions.hh, to make the
compaction module more self-contained.
Some files in compaction/ have using namespace {compaction,sstables}
clauses, some even in headers. This is considered bad practice and
muddies the namespace use. Remove them.
The namespace usage in this directory is very inconsistent, with files
and classes scattered in:
* global namespace
* namespace compaction
* namespace sstables
With cases, where all three used in the same file. This code used to
live in sstables/ and some of it still retains namespace sstables as a
heritage of that time. The mismatch between the dir (future module) and
the namespace used is confusing, so finish the migration and move all
code in compaction/ to namespace compaction too.
This patch, although large, is mechanic and only the following kind of
changes are made:
* replace namespace sstable {} with namespace compaction {}
* add namespace compaction {}
* drop/add sstables::
* drop/add compaction::
* move around forward-declarations so they are in the correct namespace
context
This refactoring revealed some awkward leftover coupling between
sstables and compaction, in sstables/sstable_set.cc, where the
make_sstable_set() methods of compaction strategies are implemented.
This PR improves the handling of malformed SSTables during scrub and adds tests to validate the updated behavior.
When scrub is used, there is an increased chance of encountering malformed SSTables. These should not be retried as in regular compaction. Instead, they must be handled according to the selected scrub mode: in skip mode, in case of malformed_sstable_exception, invalid data or whole SSTable should be removed, in abort and segregate modes, the scrub process should abort.
Previously, all modes treated malformed_sstable_exception the same way, causing scrub to abort even when skip mode was selected. This PR updates the scrub logic to properly handle malformed SSTable exceptions based on the selected mode.
Unit tests are added to verify the intended behavior.
Fixesscylladb/scylladb#19059
Backport is not required, it is an improvement
Closesscylladb/scylladb#25828
* github.com:scylladb/scylladb:
sstable_compaction_test: add scrub tests for malformed SSTables
scrub: skip sstable on malformed sstable exception in skip mode
As requested in #22104, moved the files and fixed other includes and build system.
Moved files:
- combine.hh
- collection_mutation.hh
- collection_mutation.cc
- converting_mutation_partition_applier.hh
- converting_mutation_partition_applier.cc
- counters.hh
- counters.cc
- timestamp.hh
Fixes: #22104
This is a cleanup, no need to backport
Closesscylladb/scylladb#25085
Add unit tests for scrub behavior with malformed SSTables:
- sstable_scrub_abort_mode_malformed_sstable_test(verifies scrub aborts on malformed SSTables)
- sstable_scrub_skip_mode_malformed_sstable_test(verifies scrub skips malformed SSTables without aborting)
Currently, compaction::task_manager_module is stopped in compaction_manager::stop,
concurrently to really_do_stop. We can't predict the order of the two.
Do not set _task_manager_module to nullptr at stop, because
compaction_manager::really_do_stop() may be called before the actual
shutdown, while other components still try to use it.
compaction::task_manager_module does not keep a pointer to compaction_manager,
so we won't end up with memory leak.
Stop compaction module in really_do_stop, after ongoing compactions
are stopped.
It's a preparation for further patches.
When `scrub --validate` runs, it collects all candidate sstables at the
start and validates them one by one in separate compaction tasks.
However, scrub in validate mode does not register these sstables for
compaction, which allows regular compaction to pick them up and
potentially compact them away before validation begins. This leads to
scrub failures because the sstables can no longer be found.
This patch fixes the issue by first disabling compaction, collecting the
sstables, and then registering them for compaction before starting
validation. This ensures that the enqueued sstables remain available for
the entire duration of the scrub validation task.
Fixes#23363
Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
The central idea of incremental repair is to allow repair participants
to select and repair only a portion of the dataset to speed up the
repair process. All repair participants must utilize an identical
selection method to repair and synchronize the same selected dataset.
There are two primary selection methods: time-based and file-based. The
time-based method selects data within a specified time frame. It is
versatile but it is less efficient because it requires reading all of
the dataset and omitting data beyond the time frame. The file-based
method selects data from unrepaired SSTables and is more efficient
because it allows the entire SSTable to be omitted. This document patch
implements the file-based selection method.
Incremental repair will only be supported for tablet tables; it will not
be supported for vnode tables. On one hand, the legacy vnode is less
important to support. On the other hand, the incremental repair for
vnode is much harder to implement. With vnodes, a SSTalbe could contain
data for multiple vnode ranges. When a given vnode range is repaired,
only a portion of the SSTable is repaired. This complicates the
manipulation of SSTables significantly during both repair and
compaction. With tablets, an entire tablet is repaired so that a
sstable is either fully repaired or not repaired which is a huge
simplification.
This patch uses the repaired_at from sstables::statistics component to
mark a sstable as repaired. It uses a virtual clock as the repair
timestamp, i.e., using a monotonically increasing number for the
repaired_at field of a SSTable and sstables_repaired_at column in
system.tablets table. Notice that when a sstable is not repaired, the
repaired_at field will be set to the default value 0 by default. The
being_repaired in memory field of a SSTable is used to explicitly mark
that a SSTable is being selected. The following variables are used for
incremental repair:
The repaired_at on disk field of a SSTable is used.
- A 64-bit number increases sequentially
The sstables_repaired_at is added to the system.tablets table.
- repaired_at <= sstables_repaired_at means the sstable is repaired
The being_repaired in memory field of a SSTable is added.
- A repair UUID tells which sstable has participated in the repair
Initial test results:
1) Medium dataset results
Node amount: 3
Instance type: i4i.2xlarge
Disk usage per node: ~500GB
Cluster pre-populated with ~500GB of data before starting repairs job.
Results for Repair Timings:
The regular repair run took 210 mins.
Incremental repair 1st run took 183 mins, 2nd and 3rd runs took around 48s
The speedup is: 183 mins / 48s = 228X
2) Small dataset results
Node amount: 3
Instance type: i4i.2xlarge
Disk usage per node: ~167GB
Cluster pre-populated with ~167GB of data before starting the repairs job.
Regular repair 1st run took 110s, 2nd and 3rd runs took 110s.
Incremental repair 1st run took 110 seconds, 2nd and 3rd run took 1.5 seconds.
The speedup is: 110s / 1.5s = 73X
3) Large dataset results
Node amount: 6
Instance type: i4i.2xlarge, 3 racks
50% of base load, 50% read/write
Dataset == Sum of data on each node
Dataset Non-incremental repair (minutes)
1.3 TiB 31:07
3.5 TiB 25:10
5.0 TiB 19:03
6.3 TiB 31:42
Dataset Incremental repair (minutes)
1.3 TiB 24:32
3.0 TiB 13:06
4.0 TiB 5:23
4.8 TiB 7:14
5.6 TiB 3:58
6.3 TiB 7:33
7.0 TiB 6:55
Fixes#22472Closesscylladb/scylladb#24291
* github.com:scylladb/scylladb:
replica: Introduce get_compaction_reenablers_and_lock_holders_for_repair
compaction: Move compaction_reenabler to compaction_reenabler.hh
topology_coordinator: Make rpc::remote_verb_error to warning level
repair: Add metrics for sstable bytes read and skipped from sstables
test.py: Disable incremental for test_tombstone_gc_for_streaming_and_repair
test.py: Add tests for tablet incremental repair
repair: Add tablet incremental repair support
compaction: Add tablet incremental repair support
feature_service: Add TABLET_INCREMENTAL_REPAIR feature
tablet_allocator: Add tablet_force_tablet_count_increase and decrease
repair: Add incremental helpers
sstable: Add being_repaired to sstable
sstables: Add set_repaired_at to metadata_collector
mutation_compactor: Introduce add operator to compaction_stats
tablet: Add sstables_repaired_at to system.tablets table
test: Fix drain api in task_manager_client.py
This patch addes incremental_repair support in compaction.
- The sstables are split into repaired and unrepaired set.
- Repaired and unrepaired set compact sperately.
- The repaired_at from sstable and sstables_repaired_at from
system.tablets table are used to decide if a sstable is repaired or
not.
- Different compactions tasks, e.g., minor, major, scrub, split, are
serialized with tablet repair.
