Commit Graph

794 Commits

Author SHA1 Message Date
Botond Dénes
56c375b1f3 Merge 'table: don't close a disengaged querier in query()' from Pavel Emelyanov
There's a flaw in table::query() -- calling querier_opt->close() can dereferences a disengaged std::optional. The fix pretty simple. Once fixed, there are two if-s checking for querier_opt being engaged or not that are worth being merged.

The problem doesn't really shows itself becase table::query() is not called with null saved_querier, so the de-facto if is always correct. However, better to be on safe-side.

The problem doesn't show itself for real, not worth backporting

Closes scylladb/scylladb#29142

* github.com:scylladb/scylladb:
  table: merge adjacent querier_opt checks in query()
  table: don't close a disengaged querier in query()
2026-03-24 08:47:35 +02:00
Pavel Emelyanov
7dce43363e table: merge adjacent querier_opt checks in query()
After the previous fix both guarding if-s start with 'if (querier_opt &&'.
Merge them into a single outer 'if (querier_opt)' block to avoid the
redundant check and make the structure easier to follow.

No functional change.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
2026-03-20 14:48:08 +03:00
Pavel Emelyanov
9c1c41df03 table: don't close a disengaged querier in query()
The condition guarding querier_opt->close() was:

When saved_querier is null the short-circuit makes the whole condition true
regardless of whether querier_opt is engaged.  If partition_ranges is empty,
query_state::done() is true before the while-loop body ever runs, so querier_opt
is never created.  Calling querier_opt->close() then dereferences a disengaged
std::optional — undefined behaviour.

Fix by checking querier_opt first:

This preserves all existing semantics (close when not saving, or when saving
wouldn't be useful) while making the no-querier path safe.

Why this doesn't surface today: the sole production call site, database::query(),
in practice.  The API header documents nullptr as valid ("Pass nullptr when
queriers are not saved"), so the bug is real but latent.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
2026-03-20 12:25:13 +03:00
Botond Dénes
5573c3b18e Merge 'tablets: Fix deadlock in background storage group merge fiber' from Tomasz Grabiec
When it deadlocks, groups stop merging and compaction group merge
backlog will run-away.

Also, graceful shutdown will be blocked on it.

Found by flaky unit test
test_merge_chooses_best_replica_with_odd_count, which timed-out in 1
in 100 runs.

Reason for deadlock:

When storage groups are merged, the main compaction group of the new
storage group takes a compaction lock, which is appended to
_compaction_reenablers_for_merging, and released when the merge
completion fiber is done with the whole batch.

If we accumulate more than 1 merge cycle for the fiber, deadlock
occurs. Lock order will be this

Initial state:

 cg0: main
 cg1: main
 cg2: main
 cg3: main

After 1st merge:

 cg0': main [locked], merging_groups=[cg0.main, cg1.main]
 cg1': main [locked], merging_groups=[cg2.main, cg3.main]

After 2nd merge:

 cg0'': main [locked], merging_groups=[cg0'.main [locked], cg0.main, cg1.main, cg1'.main [locked], cg2.main, cg3.main]

merge completion fiber will try to stop cg0'.main, which will be
blocked on compaction lock. which is held by the reenabler in
_compaction_reenablers_for_merging, hence deadlock.

The fix is to wait for background merge to finish before we start the
next merge. It's achieved by holding old erm in the background merge,
and doing a topology barrier from the merge finalizing transition.

Background merge is supposed to be a relatively quick operation, it's
stopping compaction groups. So may wait for active requests. It
shouldn't prolong the barrier indefinitely.

Tablet tests which trigger merge need to be adjusted to call the
barrier, otherwise they will be vulnerable to the deadlock.

Fixes SCYLLADB-928

Backport to >= 2025.4 because it's the earliest vulnerable due to f9021777d8.

Closes scylladb/scylladb#29007

* github.com:scylladb/scylladb:
  tablets: Fix deadlock in background storage group merge fiber
  replica: table: Propagate old erm to storage group merge
  test: boost: tablets_test: Save tablet metadata when ACKing split resize decision
  storage_service: Extract local_topology_barrier()
2026-03-20 09:05:52 +02:00
Avi Kivity
6b259babeb Merge 'logstor: initial log-structured storage for key-value tables' from Michael Litvak
Introduce an initial and experimental implementation of an alternative log-structured storage engine for key-value tables.

Main flows and components:
* The storage is composed of 32MB files, each file divided to segments of size 128k. We write to them sequentially records that contain a mutation and additional metadata. Records are written to a buffer first and then written to the active segment sequentially in 4k sized blocks.
* The primary index in memory maps keys to their location on disk. It is a B-tree per-table that is ordered by tokens, similar to a memtable.
* On reads we calculate the key and look it up in the primary index, then read the mutation from disk with a single disk IO.
* On writes we write the record to a buffer, wait for it to be written to disk, then update the index with the new location, and free the previous record.
* We track the used space in each segment. When overwriting a record, we increase the free space counter for the segment of the previous record that becomes dead. We store the segments in a histogram by usage.
* The compaction process takes segments with low utilization, reads them and writes the live records to new segments, and frees the old segments.
* Segments are initially "mixed" - we write to the active segment records from all tables and all tablets. The "separator" process rewrites records from mixed segments into new segments that are organized by compaction groups (tablets), and frees the mixed segments. Each write is written to the active segment and to a separator buffer of the compaction group, which is eventually flushed to a new segment in the compaction group.

Currently this mode is experimental and requires an experimental flag to be enabled.
Some things that are not supported yet are strong consistency, tablet migration, tablet split/merge, big mutations, tombstone gc, ttl.

to use, add to config:
```
enable_logstor: true

experimental_features:
  - logstor
```

create a table:
```
CREATE TABLE ks.t(pk int PRIMARY KEY, a int, v text) WITH storage_engine = 'logstor';
```

INSERT, SELECT, DELETE work as expected
UPDATE not supported yet

no backport - new feature

Closes scylladb/scylladb#28706

* github.com:scylladb/scylladb:
  logstor: trigger separator flush for buffers that hold old segments
  docs/dev: add logstor documentation
  logstor: recover segments into compaction groups
  logstor: range read
  logstor: change index to btree by token per table
  logstor: move segments to replica::compaction_group
  db: update dirty mem limits dynamically
  logstor: track memory usage
  logstor: logstor stats api
  logstor: compaction buffer pool
  logstor: separator: flush buffer when full
  logstor: hold segment until index updates
  logstor: truncate table
  logstor: enable/disable compaction per table
  logstor: separator buffer pool
  test: logstor: add separator and compaction tests
  logstor: segment and separator barrier
  logstor: separator debt controller
  logstor: compaction controller
  logstor: recovery: recover mixed segments using separator
  logstor: wait for pending reads in compaction
  logstor: separator
  logstor: compaction groups
  logstor: cache files for read
  logstor: recovery: initial
  logstor: add segment generation
  logstor: reserve segments for compaction
  logstor: index: buckets
  logstor: add buffer header
  logstor: add group_id
  logstor: record generation
  logstor: generation utility
  logstor: use RIPEMD-160 for index key
  test: add test_logstor.py
  api: add logstor compaction trigger endpoint
  replica: add logstor to db
  schema: add logstor cf property
  logstor: initial commit
  db: disable tablet balancing with logstor
  db: add logstor experimental feature flag
2026-03-20 00:18:09 +02:00
Botond Dénes
4981e72607 Merge 'replica: avoid unnecessary computation on token lookup hot path' from Łukasz Paszkowski
`storage_group_of()` sits on the replica-side token lookup hot path, yet it called `tablet_map::get_tablet_id_and_range_side()`, which always computes both the tablet id and the post-split range side — even though most callers only need the storage group id.

The range-side computation is only relevant when a storage group is in tablet splitting mode, but we were paying for it unconditionally on every lookup.

This series fixes that by:

1. Adding `tablet_map::get_tablet_range_side()` so the range side can be computed independently when needed.
2. Adding lazy `select_compaction_group()` overloads that defer the range-side computation until splitting mode is actually active.
3. Switching `storage_group_of()` to use the cheaper `get_tablet_id()` path, only computing the range side on demand.

Improvements. No backport is required.

Closes scylladb/scylladb#28963

* github.com:scylladb/scylladb:
  replica/table: avoid computing token range side in storage_group_of() on hot path
  replica/compaction_group: add lazy select_compaction_group() overloads
  locator/tablets: add tablet_map::get_tablet_range_side()
2026-03-19 14:27:12 +02:00
Pavel Emelyanov
f27dc12b7c Merge 'Fix directory lister leak in table::get_snapshot_details: ' from Benny Halevy
As reported in SCYLLADB-1013, the directory lister must be closed also when an exception is thrown.

For example, see backtrace below:
```
seastar::on_internal_error(seastar::logger&, std::basic_string_view<char, std::char_traits<char>>) at ./build/release/seastar/./seastar/src/core/on_internal_error.cc:57
directory_lister::~directory_lister() at ./utils/lister.cc:77
replica::table::get_snapshot_details(std::filesystem::__cxx11::path, std::filesystem::__cxx11::path) (.resume) at ./replica/table.cc:4081
std::__n4861::coroutine_handle<seastar::internal::coroutine_traits_base<db::snapshot_ctl::table_snapshot_details>::promise_type>::resume() const at /usr/lib/gcc/x86_64-redhat-linux/15/../../../../include/c++/15/coroutine:247
 (inlined by) seastar::internal::coroutine_traits_base<db::snapshot_ctl::table_snapshot_details>::promise_type::run_and_dispose() at ././seastar/include/seastar/core/coroutine.hh:129
seastar::reactor::task_queue::run_tasks() at ./build/release/seastar/./seastar/src/core/reactor.cc:2695
 (inlined by) seastar::reactor::task_queue_group::run_tasks() at ./build/release/seastar/./seastar/src/core/reactor.cc:3201
seastar::reactor::task_queue_group::run_some_tasks() at ./build/release/seastar/./seastar/src/core/reactor.cc:3185
 (inlined by) seastar::reactor::do_run() at ./build/release/seastar/./seastar/src/core/reactor.cc:3353
seastar::reactor::run() at ./build/release/seastar/./seastar/src/core/reactor.cc:3245
seastar::app_template::run_deprecated(int, char**, std::function<void ()>&&) at ./build/release/seastar/./seastar/src/core/app-template.cc:266
seastar::app_template::run(int, char**, std::function<seastar::future<int> ()>&&) at ./build/release/seastar/./seastar/src/core/app-template.cc:160
scylla_main(int, char**) at ./main.cc:756
```

Fixes: [SCYLLADB-1013](https://scylladb.atlassian.net/browse/SCYLLADB-1013)

* Requires backport to 2026.1 since the leak exists since 004c08f525

[SCYLLADB-1013]: https://scylladb.atlassian.net/browse/SCYLLADB-1013?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ

Closes scylladb/scylladb#29084

* github.com:scylladb/scylladb:
  test/boost/database_test: add test_snapshot_ctl_details_exception_handling
  table: get_snapshot_details: fix indentation inside try block
  table: per-snapshot get_snapshot_details: fix typo in comment
  table: per-snapshot get_snapshot_details: always close lister using try/catch
  table: get_snapshot_details: always close lister using deferred_close
2026-03-19 12:40:23 +03:00
Michael Litvak
31d339e54a logstor: trigger separator flush for buffers that hold old segments
A compaction group has a separator buffer that holds the mixed segments
alive until the separator buffer is flushed. A mixed segment can be
freed only after all separator buffers that hold writes from the segment
are flushed.

Typically a separator buffer is flushed when it becomes full. However
it's possible for example that one compaction groups is filled slower
than others and holds many segments.

To fix this we trigger a separator flush periodically for separator
buffers that hold old segments. We track the active segment sequence
number and for each separator buffer the oldest sequence number it
holds.
2026-03-18 19:24:28 +01:00
Michael Litvak
a0da07e5b7 logstor: recover segments into compaction groups
Fix the logstor recovery to work with compaction groups. When recovering
a segment find its token range and add it to the appropriate compaction
groups. if it doesn't fit in a single compaction group then write each
record to its compaction group's separator buffer.
2026-03-18 19:24:28 +01:00
Michael Litvak
24379acc76 logstor: range read
extend the logstor mutation reader to support range read
2026-03-18 19:24:28 +01:00
Michael Litvak
a9d0211a64 logstor: change index to btree by token per table
Change the primary index to be a btree that is ordered by token,
similarly to a memtable, and create a index per-table instead of a
single global index.
2026-03-18 19:24:28 +01:00
Michael Litvak
e7c3942d43 logstor: move segments to replica::compaction_group
Add a segment_set member to replica::compaction_group that manages the
logstor segments that belong to the compaction group, similarly to how
it manages sstables. Add also a separator buffer in each compaction
group.

When writing a mutation to a compaction group, the mutation is written
to the active segment and to the separator buffer of the compaction
group, and when the separator buffer is flushed the segment is added to
the compaction_group's segment set.
2026-03-18 19:24:28 +01:00
Michael Litvak
bd66edee5c logstor: truncate table
implement freeing all segments of a table for table truncate.

first do barrier to flush all active and mixed segments and put all the
table's data in compaction groups, then stop compaction for the table,
then free the table's segments and remove the live entries from the
index.
2026-03-18 19:24:27 +01:00
Michael Litvak
489efca47c logstor: enable/disable compaction per table
add functions to enable or disable compaction for a specific compaction
group or for all compaction groups of a table.
2026-03-18 19:24:27 +01:00
Michael Litvak
ddd72a16b0 logstor: add group_id
add group_id value to each log record that is passed with the mutation
when writing it.

the group_id will be used to group log records in segments, such that a
segment will contain records only from a single group.

this will be useful for tablet migration. we want for each tablet to
have their own segments with all their records, so we can migrate them
efficiently by copying these segments.

the group_id value is set to a value equivalent to the tablet id.
2026-03-18 19:24:26 +01:00
Michael Litvak
2128b1b15c replica: add logstor to db
Add a single logstor instance in the database that is used for writing
and reading to tables with kv storage
2026-03-18 19:24:26 +01:00
Calle Wilund
0013f22374 memtable_test::memtable_flush_period: Change sleep to use injection signal instead
Fixes: SCYLLADB-942

Adds an injection signal _from_ table::seal_active_memtable to allow us to
reliably wait for flushing. And does so.

Closes scylladb/scylladb#29070
2026-03-18 16:23:13 +02:00
Botond Dénes
ae17596c2a Merge 'Demote log level on split failure during shutdown' from Raphael Raph Carvalho
Since commit 509f2af8db, gate_closed_exception can be triggered for ongoing split during shutdown. The commit is correct, but it causes split failure on shutdown to log an error, which causes CI instability. Previously, aborted_exception would be triggered instead which is logged as warning. Let's do the same.

Fixes https://scylladb.atlassian.net/browse/SCYLLADB-951.
Fixes https://github.com/scylladb/scylladb/issues/24850.

Only 2026.1 is affected.

Closes scylladb/scylladb#29032

* github.com:scylladb/scylladb:
  replica: Demote log level on split failure during shutdown
  service: Demote log level on split failure during shutdown
2026-03-18 16:21:05 +02:00
Benny Halevy
c2a6d1e930 test/boost/database_test: add test_snapshot_ctl_details_exception_handling
Verify that the directory listers opened by get_snapshot_details
are properly closed when handling an (injected) exception.

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2026-03-18 09:37:44 +02:00
Benny Halevy
6dc4ea766b table: get_snapshot_details: fix indentation inside try block
Whitespace-only change: indent the loop body one level inside the
try block added in the previous commit.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2026-03-18 09:28:50 +02:00
Benny Halevy
b09d45b89a table: per-snapshot get_snapshot_details: fix typo in comment
The comment says the snapshot directory may contain a `schema.sql` file,
but the code treats `schema.cql` as the special-case schema file.

Reported-by: Copilot <223556219+Copilot@users.noreply.github.com>
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2026-03-18 09:27:40 +02:00
Benny Halevy
580cc309d2 table: per-snapshot get_snapshot_details: always close lister using try/catch
Since this is a coroutine, we cannot just use deferred_close,
but rather we need to catch an error, close the lister, and then
return the error, is applicable.

Fixes: SCYLLADB-1013

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2026-03-18 09:27:23 +02:00
Benny Halevy
78c817f71e table: get_snapshot_details: always close lister using deferred_close
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2026-03-18 09:26:26 +02:00
Raphael S. Carvalho
ee87b66033 replica: Demote log level on split failure during shutdown
Dtest failed with:

table - Failed to load SSTable .../me-3gyn_0qwi_313gw2n2y90v2j4fcv-big-Data.db
of origin memtable due to std::runtime_error (Cannot split
.../me-3gyn_0qwi_313gw2n2y90v2j4fcv-big-Data.db because manager has compaction
disabled, reason might be out of space prevention), it will be unlinked...

The reason is that the error above is being triggered when the cause is
shutdown, not out of space prevention. Let's distinguish between the two
cases and log the error with warning level on shutdown.

Fixes https://github.com/scylladb/scylladb/issues/24850.

Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
2026-03-16 12:03:17 -03:00
Tomasz Grabiec
518470e89e Merge 'load_stats: improve tablet filtering for load stats' from Ferenc Szili
When computing table sizes via load_stats to determine if a split/merge is needed, we are filtering tablets which are being migrated, in order to avoid counting them twice (both on leaving and pending replica) in the total table size. The tablets are filtered so that they are counted on the leaving replica until the streaming stage, and on the pending replica after the streaming stage.

Currently, the procedure for collecting tablet sizes for load balancing also uses this same filter. This should be changed, because the load balancer needs to have as much information about tablet sizes as possible, and could ignore a node due to missing tablet sizes for tablets in the `write_both_read_new` and `use_new` stages.

For tablet size collection, we should include all the tablets which are currently taking up disk space. This means:
- on leaving replica, include all tablets until the `cleanup` stage
- on pending replica, include all tablets starting with the `write_both_read_new` and later stages

While this is an improvement, it causes problems with some of the tests, and therefore needs to be backported to 2026.1

Fixes: SCYLLADB-829

Closes scylladb/scylladb#28587

* github.com:scylladb/scylladb:
  load_stats: add filtering for tablet sizes
  load_stats: move tablet filtering for table size computation
  load_stats: bring the comment and code in sync
2026-03-13 13:08:11 +01:00
Tomasz Grabiec
1256a9faa7 tablets: Fix deadlock in background storage group merge fiber
When it deadlocks, groups stop merging and compaction group merge
backlog will run-away.

Also, graceful shutdown will be blocked on it.

Found by flaky unit test
test_merge_chooses_best_replica_with_odd_count, which timed-out in 1
in 100 runs.

Reason for deadlock:

When storage groups are merged, the main compaction group of the new
storage group takes a compaction lock, which is appended to
_compaction_reenablers_for_merging, and released when the merge
completion fiber is done with the whole batch.

If we accumulate more than 1 merge cycle for the fiber, deadlock
occurs. Lock order will be this

Initial state:

 cg0: main
 cg1: main
 cg2: main
 cg3: main

After 1st merge:

 cg0': main [locked], merging_groups=[cg0.main, cg1.main]
 cg1': main [locked], merging_groups=[cg2.main, cg3.main]

After 2nd merge:

 cg0'': main [locked], merging_groups=[cg0'.main [locked], cg0.main, cg1.main, cg1'.main [locked], cg2.main, cg3.main]

merge completion fiber will try to stop cg0'.main, which will be
blocked on compaction lock. which is held by the reenabler in
_compaction_reenablers_for_merging, hence deadlock.

The fix is to wait for background merge to finish before we start the
next merge. It's achieved by holding old erm in the background merge,
and doing a topology barrier from the merge finalizing transition.

Background merge is supposed to be a relatively quick operation, it's
stopping compaction groups. So may wait for active requests. It
shouldn't prolong the barrier indefinitely.

Tablet boost unit tests which trigger merge need to be adjusted to
call the barrier, otherwise they will be vulnerable to the deadlock.

Two cluster tests were removed because they assumed that merge happens
in the backgournd. Now that it happens as part of merge finalization,
and blocks topology state machine, those tests deadlock because they
are unable to make topology changes (node bootstrap) while background
merge is blocked.

The test "test_tablets_merge_waits_for_lwt" needed to be adjusted. It
assumed that merge finalization doesn't wait for the erm held by the
LWT operation, and triggered tablet movement afterwards, and assumed
that this migration will issue a barrier which will block on the LWT
operation. After this commit, it's the barrier in merge finalization
which is blocked. The test was adjusted to use an earlier log mark
when waiting for "Got raft_topology_cmd::barrier_and_drain", which
will catch the barrier in merge finalization.

Fixes SCYLLADB-928
2026-03-12 22:45:01 +01:00
Tomasz Grabiec
7706c9e8c4 replica: table: Propagate old erm to storage group merge 2026-03-12 22:45:01 +01:00
Botond Dénes
475220b9c9 Merge 'Remove the rest of pre raft topology code' from Gleb Natapov
Remove the rest of the code that assumes that either group0 does not exist yet or a cluster is till not upgraded to raft topology. Both of those are not supported any more.

No need to backport since we remove functionality here.

Closes scylladb/scylladb#28841

* github.com:scylladb/scylladb:
  service level: remove version 1 service level code
  features: move GROUP0_SCHEMA_VERSIONING to deprecated features list
  migration_manager: remove unused forward definitions
  test: remove unused code
  auth: drop auth_migration_listener since it does nothing now
  schema: drop schema_registry_entry::maybe_sync() function
  schema: drop make_table_deleting_mutations since it should not be needed with raft
  schema: remove calculate_schema_digest function
  schema: drop recalculate_schema_version function and its uses
  migration_manager: drop check for group0_schema_versioning feature
  cdc: drop usage of cdc_local table and v1 generation definition
  storage_service: no need to add yourself to the topology during reboot since raft state loading already did it
  storage_service: remove unused functions
  group0: drop with_raft() function from group0_guard since it always returns true now
  gossiper: do not gossip TOKENS and CDC_GENERATION_ID any more
  gossiper: drop tokens from loaded_endpoint_state
  gossiper: remove unused functions
  storage_service: do not pass loaded_peer_features to join_topology()
  storage_service: remove unused fields from replacement_info
  gossiper: drop is_safe_for_restart() function and its use
  storage_service: remove unused variables from join_topology
  gossiper: remove the code that was only used in gossiper topology
  storage_service: drop the check for raft mode from recovery code
  cdc: remove legacy code
  test: remove unused injection points
  auth: remove legacy auth mode and upgrade code
  treewide: remove schema pull code since we never pull schema any more
  raft topology: drop upgrade_state and its type from the topology state machine since it is not used any longer
  group0: hoist the checks for an illegal upgrade into main.cc
  api: drop get_topology_upgrade_state and always report upgrade status as done
  service_level_controller: drop service level upgrade code
  test: drop run_with_raft_recovery parameter to cql_test_env
  group0: get rid of group0_upgrade_state
  storage_service: drop topology_change_kind as it is no longer needed
  storage_service: drop check_ability_to_perform_topology_operation since no upgrades can happen any more
  service_storage: remove unused functions
  storage_service: remove non raft rebuild code
  storage_service: set topology change kind only once
  group0: drop in_recovery function and its uses
  group0: rename use_raft to maintenance_mode and make it sync
2026-03-11 10:24:20 +02:00
Robert Bindar
29619e48d7 replica/table: calculate manifest tablet_count from tablet map
During tests I noticed that if the number of tablets is very small,
say 2, and the number of nodes is 3 (2 shards per node), using the
number of storage groups on each shard, a shard may end up holding 0 groups,
whilst the other holds 1 group. And in some nodes even both shards have
0 groups.
Taking the minimum among shards here was showing in manifests a tablet
count of 0 for all 3 nodes, which is incorrect.

Signed-off-by: Robert Bindar <robert.bindar@scylladb.com>

Closes scylladb/scylladb#28978
2026-03-11 09:27:04 +02:00
Raphael S. Carvalho
cc5b1acadf Improve log when sstable load fails due to missing tablet replica
A bug or some bad operator intervention can lead to a sstable existing in a
node after the tablet replica was moved to a different node.

This will result sstable loading during boot failing, requiring operator
intervention.
The log today just dumps the name of the "orphaned" sstable, but one
investigating it might want to know which process (repair, memtable, whatever)
generated that sstable, if the sstable was created locally or remotely,
and the current replica set of the underlying tablet.
From the original identifier, we can know the exact time the sstable was
created on its original node. From the current id, we know the time it
was created on the current node.
All this info can help the investigator to correlate with events in other nodes
(includes actions from the coordinator) to get closer to the root cause.

The new log will look like this:

"Unable to load SSTable .../me-3gyg_1fsw_2u0u826b00b71vc46o-big-Data.db
(originated from compaction with id 913f41c0-18c2-11f1-8f08-cb8521b3f330
on host e483238c-2287-4022-8bc4-b4f1c4cb2b0d)
of tablet 6 (replica set: [e483238c-2287-4022-8bc4-b4f1c4cb2b0d:0])"

Refs https://scylladb.atlassian.net/browse/SCYLLADB-788.

Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>

Closes scylladb/scylladb#28921
2026-03-11 06:20:34 +02:00
Botond Dénes
81e214237f Merge 'Add digests for all sstable components in scylla metadata' from Taras Veretilnyk
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/27453

Closes scylladb/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
2026-03-10 16:02:53 +02:00
Gleb Natapov
0b508c5f96 test: remove unused injection points
Also remove test_auth_raft_command_split test which is irrelevant since 5ba7d1b116
because it does not use the function that injects max sized command after the
commit.
2026-03-10 10:09:39 +02:00
Łukasz Paszkowski
147b355326 replica/table: avoid computing token range side in storage_group_of() on hot path
`storage_group_of()` is on the replica-side token lookup hot path but
used `tablet_map::get_tablet_id_and_range_side()`, which computes both
tablet id and post-split range side.

Most callers only need the storage group id. Switch `storage_group_of()`
to use `get_tablet_id()` via `tablet_id_for_token()`, and select the
compaction group via new overloads that compute the range side only
when splitting mode is active.
2026-03-09 17:59:36 +01:00
Łukasz Paszkowski
419e9aa323 replica/compaction_group: add lazy select_compaction_group() overloads
Change `storage_group::select_compaction_group()` to accept a token
(and tablet_map) and compute the tablet range side only when
splitting_mode() is active.

Add an overload for selecting the compaction group for an sstable
spanning a token range.
2026-03-09 17:59:36 +01:00
Botond Dénes
509f2af8db Merge 'repair: Fix rwlock in compaction_state and lock holder lifecycle' from Raphael Raph Carvalho
Consider this:

- repair takes the lock holder
- tablet merge filber destories the compaction group and the compaction state
- repair fails
- repair destroy the lock holder

This is observed in the test:

```
repair - repair[5d73d094-72ee-4570-a3cc-1cd479b2a036] Repair 1 out of 1 tablets: table=sec_index.users range=(432345564227567615,504403158265495551] replicas=[0e9d51a5-9c99-4d6e-b9db-ad36a148b0ea:15, 498e354c-1254-4d8d-a565-2f5c6523845a:9, 5208598c-84f0-4526-bb7f-573728592172:28]

...

repair - repair[5d73d094-72ee-4570-a3cc-1cd479b2a036]: Started to repair 1 out of 1 tables in keyspace=sec_index, table=users, table_id=ea2072d0-ccd9-11f0-8dba-c5ab01bffb77, repair_reason=repair
repair - Enable incremental repair for table=sec_index.users range=(432345564227567615,504403158265495551]
table - Disabled compaction for range=(432345564227567615,504403158265495551] session_id=a13a72cc-cd2d-11f0-8e9b-76d54580ab09 for incremental repair
table - Got unrepaired compaction and repair lock for range=(432345564227567615,504403158265495551] session_id=a13a72cc-cd2d-11f0-8e9b-76d54580ab09 for incremental repair
table - Disabled compaction for range=(432345564227567615,504403158265495551] session_id=a13a72cc-cd2d-11f0-8e9b-76d54580ab09 for incremental repair
table - Got unrepaired compaction and repair lock for range=(432345564227567615,504403158265495551] session_id=a13a72cc-cd2d-11f0-8e9b-76d54580ab09 for incremental repair
repair - repair[5d73d094-72ee-4570-a3cc-1cd479b2a036]: get_sync_boundary: got error from node=0e9d51a5-9c99-4d6e-b9db-ad36a148b0ea, keyspace=sec_index, table=users, range=(432345564227567615,504403158265495551], error=seastar::rpc::remote_verb_error (Compaction state for table [0x60f008fa34c0] not found)
compaction_manager - Stopping 1 tasks for 1 ongoing compactions for table sec_index.users compaction_group=238 due to tablet merge
compaction_manager - Stopping 1 tasks for 1 ongoing compactions for table sec_index.users compaction_group=238 due to tablet merge

....

scylla[10793] Segmentation fault on shard 28, in scheduling group streaming
```

The rwlock in compaction_state could be destroyed before the lock holder
of the rwlock is destroyed. This causes user after free when the lock
the holder is destroyed.

To fix it, users of repair lock will now be waited when a compaction
group is being stopped.
That way, compaction group - which controls the lifetime of rwlock -
cannot be destroyed while the lock is held.
Additionally, the merge completion fiber - that might remove groups -
is properly serialized with incremental repair.

The issue can be reproduced using sanitize build consistently and can not
be reproduced after the fix.

Fixes #27365

Closes scylladb/scylladb#28823

* github.com:scylladb/scylladb:
  repair: Fix rwlock in compaction_state and lock holder lifecycle
  repair: Prevent repair lock holder leakage after table drop
2026-03-05 14:18:25 +02:00
Asias He
225b10b683 repair: Fix rwlock in compaction_state and lock holder lifecycle
Consider this:

- repair takes the lock holder
- tablet merge filber destories the compaction group and the compaction state
- repair fails
- repair destroy the lock holder

This is observed in the test:

```
repair - repair[5d73d094-72ee-4570-a3cc-1cd479b2a036] Repair 1 out of 1 tablets: table=sec_index.users range=(432345564227567615,504403158265495551] replicas=[0e9d51a5-9c99-4d6e-b9db-ad36a148b0ea:15, 498e354c-1254-4d8d-a565-2f5c6523845a:9, 5208598c-84f0-4526-bb7f-573728592172:28]

...

repair - repair[5d73d094-72ee-4570-a3cc-1cd479b2a036]: Started to repair 1 out of 1 tables in keyspace=sec_index, table=users, table_id=ea2072d0-ccd9-11f0-8dba-c5ab01bffb77, repair_reason=repair
repair - Enable incremental repair for table=sec_index.users range=(432345564227567615,504403158265495551]
table - Disabled compaction for range=(432345564227567615,504403158265495551] session_id=a13a72cc-cd2d-11f0-8e9b-76d54580ab09 for incremental repair
table - Got unrepaired compaction and repair lock for range=(432345564227567615,504403158265495551] session_id=a13a72cc-cd2d-11f0-8e9b-76d54580ab09 for incremental repair
table - Disabled compaction for range=(432345564227567615,504403158265495551] session_id=a13a72cc-cd2d-11f0-8e9b-76d54580ab09 for incremental repair
table - Got unrepaired compaction and repair lock for range=(432345564227567615,504403158265495551] session_id=a13a72cc-cd2d-11f0-8e9b-76d54580ab09 for incremental repair
repair - repair[5d73d094-72ee-4570-a3cc-1cd479b2a036]: get_sync_boundary: got error from node=0e9d51a5-9c99-4d6e-b9db-ad36a148b0ea, keyspace=sec_index, table=users, range=(432345564227567615,504403158265495551], error=seastar::rpc::remote_verb_error (Compaction state for table [0x60f008fa34c0] not found)
compaction_manager - Stopping 1 tasks for 1 ongoing compactions for table sec_index.users compaction_group=238 due to tablet merge
compaction_manager - Stopping 1 tasks for 1 ongoing compactions for table sec_index.users compaction_group=238 due to tablet merge

....

scylla[10793] Segmentation fault on shard 28, in scheduling group streaming
```

The rwlock in compaction_state could be destroyed before the lock holder
of the rwlock is destroyed. This causes user after free when the lock
the holder is destroyed.

To fix it, users of repair lock will now be waited when a compaction
group is being stopped.
That way, compaction group - which controls the lifetime of rwlock -
cannot be destroyed while the lock is held.
Additionally, the merge completion fiber - that might remove groups -
is properly serialized with incremental repair.

The issue can be reproduced using sanitize build consistently and can not
be reproduced after the fix.

Fixes #27365

Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
2026-03-03 21:05:15 -03:00
Botond Dénes
4f5310bc72 replica/table: update rf=1 table registry in shared tombstone-gc state
On every update of the ERM, update the state of the current table in the
registry of RF=1 tables in shared tombstone gc state.
Ensures that tombstone gc stops collection of tombstones in immediate
mode as soon as the table starts transitioning away from RF=1.
2026-03-03 14:09:28 +02:00
Botond Dénes
6364e35403 replica/table: add get_tombstone_gc_state()
Shorthand for
get_compaction_manager().get_shared_tombstone_gc_state().get_tombstone_gc_state().
2026-03-03 14:09:28 +02:00
Botond Dénes
f3ee6a0bd1 compaction: use tombstone_gc_state with value semantics
Instead of passing around references to it, pass around values.

This object is now designed to be used as a value-type, after recent
refactoring.
2026-03-03 14:09:27 +02:00
Botond Dénes
83e20d920e db/row_cache: use tombstone_gc_state with value semantics
Instead of keeping a pointer to it. Replace nullptr with
tombstone_gc_state::no_gc().

This object is now designed to be used as a value-type, after recent
refactoring.
2026-03-03 14:09:27 +02:00
Calle Wilund
69f8e722bf table::snapshot_table_on_all_shards: Use set to keep track of tablets in manifest
Fixes: SCYLLADB-828

Avoid iterating linear set of tablets when building manifest. Reduces complexity.

Closes scylladb/scylladb#28851
2026-03-03 08:09:33 +02:00
Taras Veretilnyk
5bbc44ed12 sstables: replace rewrite_statistics with new rewrite component mechanism
This commits migrates all callers that used rewrite_statistics to new
rewrite component mechanism.
2026-02-26 22:38:55 +01:00
Taras Veretilnyk
4aa0a3acf9 compaction: add compaction_group_view method to specify sstable version
Add make_sstable() overload that accepts sstable_version_types parameter
to compaction_group_view interface and all implementations.
This will be useful in rewrite component mechanism, as we
need to preserve sstable version when creating the new one for the replacement.
2026-02-26 22:38:55 +01:00
Ferenc Szili
f22d75a57e load_stats: add filtering for tablet sizes
This patch adds filtering for tablet sizes collected in load_stats.
This is needed to improve the chances that the balancer will have all
the tablet sizes for the node, and that way avoid having the node
ignored during balancing.
2026-02-26 15:17:39 +01:00
Ferenc Szili
d0a5a1d5d0 load_stats: move tablet filtering for table size computation
This patch moves the table size tablet filtering code from a lambda in
storage_service::load_stats_for_tablet_based_tables() to the code
section where it will be used:
tablet_storage_group_manager::table_load_stats()

This is needed to better accomodate the next commit which will add
code for filtering tablets for tablet sizes.
2026-02-26 11:07:53 +01:00
Calle Wilund
f7aa2aacfc table::manifest: Add tablet info to manifest.json
If using tablets, will add info for each tablet present in
snapshot, with repair time and token ranges + map each
sstable to its owning tablet
2026-02-23 11:37:17 +01:00
Pavel Emelyanov
525cb5b3eb table: Use fmt::to_string() to stringify compation group ID
Doing it with format("{}", foo) is correct, but to_string is
a bit more lightweight.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>

Closes scylladb/scylladb#28630
2026-02-20 14:13:15 +02:00
Petr Gusev
df73f723a6 storage_proxy: hold erms in replica handlers
Add explicit erm-holding variables in all replica-side RPC handlers.
This is required to ensure that tablet migration waits for in-flight
replica requests even if a non-replica coordinator has been fenced out.

Holding erms on the replica side may increase the global-barrier wait
time, since the barrier must drain these requests. We believe this
is acceptable because:
* We already hold erms during replica-side request execution, but in
an ad-hoc, non-systemic way in lower layers of storage_proxy
(e.g. in sp::mutate_locally and do_query_tablets).
* Replica requests are bounded by replica-side timeouts, so the
global-barrier wait time cannot exceed the maximum of these timeouts.

For Paxos verbs, we use token_metadata_guard, which wraps the ERM and
automatically refreshes it when tablet migration does not affect the
current token; see the token_metadata_guard comments for details.
We use this guard only for Paxos verbs because regular reads and writes
already hold raw erms in storage_proxy and on the coordinators.

The erms must be held in all RPC handlers that support fencing — that
is, those with a fencing_token parameter in storage_proxy.idl.
Counter updates already hold erms in
mutate_counter_on_leader_and_replicate.

Fix test_tablets2::test_timed_out_reader_after_cleanup: the tablets
barrier now waits for all nodes. As a result, the replica read
is expected to finish, rather than fail due to the tablet having
moved as it did previously. The test is renamed to
test_tablets_barrier_waits_for_replica_erms to better reflect its
purpose.

Refs scylladb/scylladb#26864
2026-02-16 08:57:42 +01:00
Pavel Emelyanov
56e212ea8d table: Fix indentation after previous patch
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2026-01-29 15:02:33 +03:00
Pavel Emelyanov
258a1a03e3 table: Use coroutine::switch_to() in try_flush_memtable_to_sstable()
It allows dropping the local lambdas passed into with_scheduling_group()
calls. Overall the code flow becomes more readable.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2026-01-29 15:01:27 +03:00