Commit Graph

651 Commits

Author SHA1 Message Date
Avi Kivity
0ae22a09d4 LICENSE: Update to version 1.1
Updated terms of non-commercial use (must be a never-customer).
2026-04-12 19:46:33 +03:00
Avi Kivity
22949bae52 Merge 'logstor: implement tablet split/merge and migration' from Michael Litvak
implement tablet split, tablet merge and tablet migration for tables that use the experimental logstor storage engine.

* tablet merge simply merges the histograms of segments of one compaction group with another.
* for tablet split we take the segments from the source compaction group, read them and write all live records to separate segments according to the split classifier, and move separated segments to the target compaction groups.
* for tablet migration we use stream_blob, similarly to file streaming of sstables. we add a new op type for streaming a logstor segment. on the source we take a snapshot of the segments with an input stream that reads the segment, and on the target we create a sink that allocates a new segment on the target shard and writes to it.
* we also do some improvements for recovery and loading of segments. we add a segment header that contains useful information for non-mixed segments, such as the table and token range.

Refs SCYLLADB-770

no backport - still a new and experimental feature

Closes scylladb/scylladb#29207

* github.com:scylladb/scylladb:
  test: logstor: additional logstor tests
  docs/dev: add logstor on-disk format section
  logstor: add version and crc to buffer header
  test: logstor: tablet split/merge and migration
  logstor: enable tablet balancing
  logstor: streaming of logstor segments using stream_blob
  logstor: add take_logstor_snapshot
  logstor: segment input/output stream
  logstor: implement compaction_group::cleanup
  logstor: tablet split
  logstor: tablet merge
  logstor: add compaction reenabler
  logstor: add segment header
  logstor: serialize writes to active segment
  replica: extend compaction_group functions for logstor
  replica: add compaction_group_for_logstor_segment
  logstor: code cleanup
2026-04-12 16:11:12 +03:00
Avi Kivity
ca80ee8586 Merge 'Introduce maintenance scheduling supergroup and do initial population' from Pavel Emelyanov
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

Closes scylladb/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
2026-04-12 00:34:48 +03:00
Michael Litvak
b71762d5da counters: reuse counter IDs by rack
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
2026-04-09 13:08:02 +02:00
Michael Litvak
78426ae31b logstor: add take_logstor_snapshot
add the function table::take_logstor_snapshot that is similar to
take_storage_snapshot for sstables.

given a token range, for each storage group in the range, it flushes the
separator buffers and then makes a snapshot of all segments in the sg's
compaction groups while disabling compaction.

the segment snapshot holds a reference to the segment so that it won't
be freed by compaction, and it provides an input stream for reading the
segment.

this will be used for tablet migration to stream the segments.
2026-03-31 18:45:08 +02:00
Michael Litvak
d3db967802 replica: add compaction_group_for_logstor_segment
add the function table::compaction_group_for_logstor_segment that we use
when recovering a segment to find the compaction group for a segment
based on its token range, similarly to compaction_group_for_sstable for
sstables.

extract the common logic from compaction_group_for_sstable to a common
function compaction_group_for_token_range that finds a compaction group
for a token range.
2026-03-31 18:40:56 +02:00
Michael Litvak
bf7bc5b410 logstor: code cleanup
misc code cleanup and small changes
2026-03-31 18:40:56 +02:00
Nikos Dragazis
0e1e6ebdc5 database: Construct migrating tables with tablet ERMs
Extend `database::add_column_family()` with a `storage_mode` argument.
If the table is under vnodes-to-tablets migration and the storage mode
is "tablets", create a tablet ERM.

Make the distributed loader determine the storage mode from topology
(`intended_storage_mode` column in system.topology).

Signed-off-by: Nikos Dragazis <nikolaos.dragazis@scylladb.com>
2026-03-24 13:20:39 +02:00
Nikos Dragazis
63399951df replica: Pick any compaction group for resharding
In the previous patch, reshard compaction was extended with a special
operation mode where SSTables from vnode-based tables are segregated on
vnode boundaries and not with the static sharder. This will later be
wired into vnodes-to-tablets migration.

The problem is that resharding requires a compaction group. With a
vnode-based table, there is only one compaction group per shard, and
this is what the current code utilizes
(`try_get_compaction_group_view_with_static_sharding()`). But the new
operation mode will apply to migrating tables, which use a
`tablet_storage_group_manager`, which creates one compaction group for
each tablet. Some compaction group needs to be selected.

Pick any compaction group that is available on the current shard.
Reshard compaction is an operation that happens early in the startup
process; compaction groups do not own any SSTables yet, so all
compaction groups are equivalent.

Signed-off-by: Nikos Dragazis <nikolaos.dragazis@scylladb.com>
2026-03-24 11:06:38 +02:00
Pavel Emelyanov
cb329b10bf code: Add maintenance/maintenance group
And move some activities from streaming group into it, namely

- tablet_allocator background group
- sstables_manager-s components reclaimer
- tablet storage group manager merge completion fiber
- prometheus

All other activity that was in streaming group remains there, but can be
moved to this group (or to new maintenance subgroup) later.

All but prometheus are patched here, prometheus still uses the
maintenance_sched_group variable in main.cc, so it transparently
moves into new group

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2026-03-23 16:00:03 +03:00
Pavel Emelyanov
de9bfe0f1d backup: Add maintenance/backup group
The snapshot_ctl::backup_task_impl runs in configured scheduling group.
Now it's streaming one. This patch introduces the maintenance/backup
group and re-configures backup task with it.

The group gets its --backup_io_throughput_mb_per_sec option that
controls bandwidth limit for this sub-group only.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2026-03-23 16:00:02 +03:00
Pavel Emelyanov
6f43e8562e compaction: Add maintenance/maintenance_compaction group
Compaction manager tells compaction_sched_group from
maintenance_compaction_sched_group. The latter, however, is set to be
"streaming" group. This patch adds real maintenance_compaction group
under the maintenance supergroup and makes compaction manager use it.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2026-03-23 16:00:02 +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
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
d69f7eb0ee db: update dirty mem limits dynamically
when logstor is enabled, update the db dirty memory limits dynamically.

previously the threshold is set to 0.5 of the available memory, so 0.5
goes to memtables and 0.5 to others (cache).

when logstor is enabled, we calculate the available memory excluding
logstor, and divide it evenly between memtables and cache.
2026-03-18 19:24:27 +01:00
Michael Litvak
b7bdb1010a logstor: logstor stats api
add api to get logstor statistics about segments for a table
2026-03-18 19:24:27 +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
31aefdc07d logstor: segment and separator barrier
add barrier operation that forces switch of the active segment and
separator, and waits for all existing segments to close and all
separators to flush.
2026-03-18 19:24:27 +01:00
Michael Litvak
1ae1f37ec1 api: add logstor compaction trigger endpoint
add a new api endpoint that triggers logstor compaction.
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
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
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
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
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
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
Pavel Emelyanov
b4b9b547ce replica: Remove unused sched groups from keyspace and table configs
Compaction and statement groups are carried over on those configs, but
are in fact unused. Drop both.

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

Closes scylladb/scylladb#28540
2026-02-19 15:47:31 +01:00
Pavel Emelyanov
5b740afe9a database: Remove streaming sched group getter
All users of it had been updated to get the streaming group elsewhere,
so this getter is no longer needed.

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

Closes scylladb/scylladb#28527
2026-02-18 12:23:35 +02:00
Pavel Emelyanov
10c278fff7 database: Remove _flush_sg member from replica::database
This field is only used to initialize the following _memtable_controller
one. It's simpler just to do the initialization with whatever value the
field itself is initialized and drop the field itself.

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

Closes scylladb/scylladb#28539
2026-02-05 13:02:35 +02:00
Piotr Dulikowski
fe9237fdc9 Merge 'alternator: don't require rf_rack flag for indexes, validate instead' from Michael Litvak
In 8df61f6d99 we changed the requirements for creating materialized
views and MV-based indexes - instead of requiring the
rf_rack_valid_keyspaces flag to be set, we now require the keyspace to
be RF-rack-valid at the time of creation, and it is enforced to remain
RF-rack-valid while the MV exists. This validation is done in the cql
create view/index statements.

The same should be done also for alternator - when creating a table with
GSI or LSI, or when adding a GSI to an existing table, previously we
required the flag rf_rack_valid_keyspaces to be set. Now we change it to
instead check if the keyspace is RF-rack-valid, and if not the operation
fails with an appropriate error.

Fixes https://github.com/scylladb/scylladb/issues/28214

backport to 2025.4 to add RF-rack-valid enforcements in alternator

Closes scylladb/scylladb#28154

* github.com:scylladb/scylladb:
  locator: document the exception type of assert_rf_rack_valid_keyspace
  alternator: don't require rf_rack flag for indexes, validate instead
2026-01-23 11:49:02 +01:00
Patryk Jędrzejczak
4e984139b2 Merge 'strongly consistent tables: basic implementation' from Petr Gusev
In this PR we add a basic implementation of the strongly-consistent tables:
* generate raft group id when a strongly-consistent table is created
* persist it into system.tables table
* start raft groups on replicas when a strongly-consistent tablet_map reaches them
* add strongly-consistent version of the storage_proxy, with the `query` and `mutate` methods
* the `mutate` method submits a command to the tablets raft group, the query method reads the data with `raft.read_barrier()`
* strongly-consistent versions of the `select_statement` and `modification_statement` are added
* a basic `test_strong_consistency.py/test_basic_write_read` is added which to check that we can write and read data in a strongly consistent fashion.

Limitations:
* for now the strongly consistent tables can have tablets only on shard zero. This is because we (ab/re) use the existing raft system tables which live only on shard0. In the next PRs we'll create separate tables for the new tablets raft groups.
* No Scylla-side proxying - the test has to figure out who is the leader and submit the command to the right node. This will be fixed separately.
* No tablet balancing -- migration/split/merges require separate complicated code.

The new behavior is hidden behind `STRONGLY_CONSISTENT_TABLES` feature, which is enabled when the `STRONGLY_CONSISTENT_TABLES` experimental feature flag is set.

Requirements, specs and general overview of the feature can be found [here](https://scylladb.atlassian.net/wiki/spaces/RND/pages/91422722/Strong+Consistency). Short term implementation plan is [here](https://docs.google.com/document/d/1afKeeHaCkKxER7IThHkaAQlh2JWpbqhFLIQ3CzmiXhI/edit?tab=t.0#heading=h.thkorgfek290)

One can check the strongly consistent writes and reads locally via cqlsh:
scylla.yaml:
```
experimental_features:
  - strongly-consistent-tables
```

cqlsh:
```
CREATE KEYSPACE IF NOT EXISTS my_ks WITH replication = {'class': 'NetworkTopologyStrategy', 'replication_factor': 1} AND tablets = {'initial': 1} AND consistency = 'local';
CREATE TABLE my_ks.test (pk int PRIMARY KEY, c int);
INSERT INTO my_ks.test (pk, c) VALUES (10, 20);
SELECT * FROM my_ks.test WHERE pk = 10;
```

Fixes SCYLLADB-34
Fixes SCYLLADB-32
Fixes SCYLLADB-31
Fixes SCYLLADB-33
Fixes SCYLLADB-56

backport: no need

Closes scylladb/scylladb#27614

* https://github.com/scylladb/scylladb:
  test_encryption: capture stderr
  test/cluster: add test_strong_consistency.py
  raft_group_registry: disable metrics for non-0 groups
  strong consistency: implement select_statement::do_execute()
  cql: add select_statement.cc
  strong consistency: implement coordinator::query()
  cql: add modification_statement
  cql: add statement_helpers
  strong consistency: implement coordinator::mutate()
  raft.hh: make server::wait_for_leader() public
  strong_consistency: add coordinator
  modification_statement: make get_timeout public
  strong_consistency: add groups_manager
  strong_consistency: add state_machine and raft_command
  table: add get_max_timestamp_for_tablet
  tablets: generate raft group_id-s for new table
  tablet_replication_strategy: add consistency field
  tablets: add raft_group_id
  modification_statement: remove virtual where it's not needed
  modification_statement: inline prepare_statement()
  system_keyspace: disable tablet_balancing for strongly_consistent_tables
  cql: rename strongly_consistent statements to broadcast statements
2026-01-23 09:52:33 +01:00
Michael Litvak
d5009882c6 locator: document the exception type of assert_rf_rack_valid_keyspace
The function assert_rf_rack_valid_keyspace uses the exception type
std::invalid_argument when the RF-rack validation fails. Document it and
change all callers to catch this specific exception type when checking
for RF-rack validation failures, so that other exception types can be
propagated properly.
2026-01-22 16:11:35 +01:00
Pavel Emelyanov
cb6ee05391 Merge 'Extend snapshot manifest.json with tablet-aware metadata' from Benny Halevy
This series extends the json manifest file we create when taking snapshots.
It adds the following metadata:
- manifesr version and scope
- snapshot name
- created_at and expires_at timestamps (#24061)
- node metadata (host_id, dc, rack)
- keyspace and table metadat
- tablet_count (#26352)
- per-sstable metadata (#26352)

Fixes [SCYLLADB-189](https://scylladb.atlassian.net/browse/SCYLLADB-189)
Fixes [SCYLLADB-195](https://scylladb.atlassian.net/browse/SCYLLADB-195)
Fixes [SCYLLADB-196](https://scylladb.atlassian.net/browse/SCYLLADB-196)

* Enhancement, no backport needed

[SCYLLADB-189]: https://scylladb.atlassian.net/browse/SCYLLADB-189?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ
[SCYLLADB-195]: https://scylladb.atlassian.net/browse/SCYLLADB-195?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ
[SCYLLADB-196]: https://scylladb.atlassian.net/browse/SCYLLADB-196?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ

Closes scylladb/scylladb#27945

* github.com:scylladb/scylladb:
  snapshot: keep per-sstable metadata in manifest.json
  snapshot: add table info and tablet_count to manifest.json
  snapshot: add basic support for snapshot ttl in manifest.json
  table: snapshot_on_all_shards: take snapshot_options
  db: snapshot_ctl: move skip_flush to struct snapshot_options
  snapshot: add snapshot name in manifest.json
  test: lib: cql_test_env: apply db::config::tablets_mode_for_new_keyspaces
  snapshot: add node info to manifest.json
  snapshot: add manifest info to manifest.json
  test: database_test: snapshot_works: add validate_manifest
2026-01-22 15:19:11 +03:00
Benny Halevy
dc9093303d snapshot: add table info and tablet_count to manifest.json
Add a table member to manifest.json with the keyspace_name,
table_name, table_id, tablets_type, and, for tablets-enabled tables, get
tablet_count on each shard and write the minimum to manifest.json.
For vnodes-based tables, tablet_count=0.

For now, `tablets_type` may be either `none` for vnodes tables, or
`powof2` for tablets tables.  In the future, when we support arbitrary
tablt boundaries, this will be reflected here, and it is likely we
would backup the whole tablets map sperately to get all tablet boundaries.

Fixes SCYLLADB-195

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2026-01-22 09:36:52 +02:00
Benny Halevy
5e90fbb9d2 table: snapshot_on_all_shards: take snapshot_options
And keep the options for now in the local_snapshot_writer.
The options will be used by following patches to pass
extra metadata like the snapshot creation time, expiration time, etc.

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2026-01-22 09:12:56 +02:00
Benny Halevy
49a3e0914d db: snapshot_ctl: move skip_flush to struct snapshot_options
So we can easily extend it and add more options.

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2026-01-22 09:12:56 +02:00
Petr Gusev
a8350b274e table: add get_max_timestamp_for_tablet
Strongly consistent writes require knowing the maximum timestamp of
locally applied mutations to guarantee monotonically increasing
timestamps for subsequent writes.

This commit adds a function that returns the maximum timestamp for a
given tablet.

Why it is safe to use this function with deleted cells:
* Tombstones are included in memtable.get_max_timestamp() calculations.
* The maximum timestamp of a memtable is used to initialize the maximum
  timestamp of the resulting sstable.
* During compaction, a new sstable’s maximum timestamp is initialized as
  the maximum of the contributing sstables.
2026-01-21 14:56:00 +01:00
Aleksandra Martyniuk
761ace4f05 config: add enforce_rack_list option
Add enforce_rack_list option. When the option is set to true,
all tablet keyspaces have rack list replication factor.

When the option is on:
- CREATE STATEMENT always auto-extends rf to rack lists;
- ALTER STATEMENT fails when there is numeric rf in any DC.

The flag is set to false by default and a node needs to be restarted
in order to change its value. Starting a node with enforce_rack_list
option will fail, if there are any tablet keyspaces with numeric rf
in any DC.

enforce_rack_list is a per-node option and a user needs to ensure
that no tablet keyspace is altered or created while nodes in
the cluster don't have the consistent value.
2026-01-20 09:58:51 +01:00
Botond Dénes
60570d7114 Merge 'topology coordinator: restrict node join/remove to preserve RF-rack validity' from Michael Litvak
Allow creating materialized views and secondary indexes in a tablets keyspace only if it's RF-rack-valid, and enforce RF-rack-validity while the keyspace has views by restricting some operations:
* Altering a keyspace's RF if it would make the keyspace RF-rack-invalid
* Adding a node in a new rack
* Removing / Decommissioning the last node in a rack

Previously the config option `rf_rack_valid_keyspaces` was required for creating views. We now remove this restriction - it's not needed because we always maintain RF-rack-validity for keyspaces with views.

The restrictions are relevant only for keyspaces with numerical RF. Keyspace with rack-list-based RF are always RF-rack-valid.

Fixes scylladb/scylladb#23345
Fixes https://github.com/scylladb/scylladb/issues/26820

backport to relevant versions for materialized views with tablets since it depends on rf-rack validity

Closes scylladb/scylladb#26354

* github.com:scylladb/scylladb:
  docs: update RF-rack restrictions
  cql3: don't apply RF-rack restrictions on vector indexes
  cql3: add warning when creating mv/index with tablets about rf-rack
  service/tablet_allocator: always allow tablet merge of tables with views
  locator: extend rf-rack validation for rack lists
  test: test rf-rack validity when creating keyspace during node ops
  locator: fix rf-rack validation during node join/remove
  test: test topology restrictions for views with tablets
  test: add test_topology_ops_with_rf_rack_valid
  topology coordinator: restrict node join/remove to preserve RF-rack validity
  topology coordinator: add validation to node remove
  locator: extend rf-rack validation functions
  view: change validate_view_keyspace to allow MVs if RF=Racks
  db: enforce rf-rack-validity for keyspaces with views
  replica/db: add enforce_rf_rack_validity_for_keyspace helper
  db: remove enforce parameter from check_rf_rack_validity
  test: adjust test to not break rf-rack validity
2026-01-09 10:01:23 +02:00
Benny Halevy
02ee341a03 memtable_list: unify can_flush and may_flush
Now that we have a unit test proving that it's safe to flush an
empty memtable list there is no need to distinguish between
may_flush and can_flush.

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2026-01-08 09:49:46 +02:00
Benny Halevy
5be6b80936 replica: table, storage_group, compaction_group: add needs_flush
Table needs flush if not all its memtable lists are empty.
To be used in the next patch for a unit test.

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2026-01-08 09:41:22 +02:00
Avi Kivity
0df85c8ae8 Revert "Merge 'Unify configuration of object storage endpoints' from Pavel Emelyanov"
This reverts commit 1bb897c7ca, reversing
changes made to 954f2cbd2f. It makes
incompatible changes to the object storage configuration format, breaking
tests [1]. It's likely that it doesn't break any production configuration,
but we can't be sure.

Fixes #27966

Closes scylladb/scylladb#27969
2026-01-05 08:53:41 +02:00
Botond Dénes
3071ccd54a Merge 'Storage-agnostic table::snapshot_on_all_shards()' from Pavel Emelyanov
The method in question knows that it writes snapshot to local filesystem and uses this actively. This PR relaxes this knowledge and splits the logic into two parts -- one that orchestrates sstables snapshot and collects the necessary metadata, and the code that writes the metadata itself.

Closes scylladb/scylladb#27762

* github.com:scylladb/scylladb:
  table: Move snapshot_file_set to table.cc
  table: Rename and move snapshot_on_all_shards() method
  table: Ditch jsondir variable
  table, sstables: Pass snapshot name to sstable::snapshot()
  table: Use snapshot_writer in write_manifest()
  table: Use snapshot_writer in write_schema_as_cql()
  table: Add snapshot_writer::sync()
  table: Add snapshot_writer::init()
  table: Introduce snapshot_writer
  table: Move final sync and rename seal_snapshot()
  table: Hide write_schema_as_cql()
  table: Hide table::seal_snapshot()
  table: Open-code finalize_snapshot()
  table: Fix indentation after previuous patch
  table: Use smp::invoke_on_all() to populate the vector with filenames
  table: Don't touch dir once more on seal_snapshot()
  table: Open-code table::take_snapshot() into caller lambda
  table: Move parts of table::take_snapshot to sstables_manager
  table: Introduce table::take_snapshot()
  table: Store the result of smp::submit_to in local variable
2025-12-24 13:46:47 +02:00
Botond Dénes
1bb897c7ca Merge 'Unify configuration of object storage endpoints' from Pavel Emelyanov
To configure S3 storage, one needs to do

```
object_storage_endpoints:
  - name: s3.us-east-1.amazonaws.com
    port: 443
    https: true
    aws_region: us-east-1
```

and for GCS it's

```
object_storage_endpoints:
  - name: https://storage.googleapis.com:433
    type: gs
    credentials_file: <gcp account credentials json file>
```

This PR updates the S3 part to look like

```
object_storage_endpoints:
  - name: https://s3.us-east-1.amazonaws.com:443
    aws_region: us-east-1
```

fixes: #26570

Not-yet released feature, no need to backport. Old configs are not accepted any longer. If it's needed, then this decision needs to be revised.

Closes scylladb/scylladb#27360

* github.com:scylladb/scylladb:
  object_storage: Temporarily handle pure endpoint addresses as endpoints
  code: Remove dangling mentions of s3::endpoint_config
  docs: Update docs according to new endpoints config option format
  object_storage: Create s3 client with "extended" endpoint name
  test: Add named constants for test_get_object_store_endpoints endpoint names
  s3/storage: Tune config updating
  sstable: Shuffle args for s3_client_wrapper
2025-12-24 06:59:02 +02:00
Pavel Emelyanov
e0cddc8c99 table: Move snapshot_file_set to table.cc
It's not used anywhere else now.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2025-12-23 12:14:36 +03:00
Pavel Emelyanov
e31b72c61f table: Rename and move snapshot_on_all_shards() method
Now it's database::snapshot_table_on_all_shards(). This is symmetric to
database::truncate_table_on_all_shards().

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2025-12-23 12:14:36 +03:00