Commit Graph

4972 Commits

Author SHA1 Message Date
Piotr Smaron
08dc1008ba db/config: enable table audit by default
In https://github.com/scylladb/scylladb/pull/27262 table audit has been
re-enabled by default in `scylla.yaml`, logging certain categories to a table,
which should make new Scylla deployments have audit enabled.
Now, in the next release, we also want to enable audit in `db/config.cc`,
which should enable audit for all deployments, which don't explicitly configure
audit otherwise in `scylla.yaml` (or via cmd line).
BTW. Because this commit aligns audit's default config values in `db/config.cc`
to those of `scylla.yaml`, `docs/reference/configuration-parameters.rst`, which
is based on `db/config.cc` will start showing that table audit is the default.

Refs: https://github.com/scylladb/scylladb/issues/28355
Refs: https://scylladb.atlassian.net/browse/SCYLLADB-222
2026-02-18 15:14:57 +01:00
Piotr Dulikowski
b9db3c9c75 Merge 'Add consistent permissions cache' from Marcin Maliszkiewicz
This patchset replaces permissions cache based on loading_cache with a new unified (permissions and roles), full, coherent auth cache.

Reason for the change is that we want to improve scenarios under stress and simplify operation manuals. New cache doesn't require any tweaking. And it behaves particularly better in scenarios with lots of schema entities (e.g. tables) combined with unprepared queries. Old cache can generate few thousands of extra internal tps due to cache refresh.

Benchmark of unprepared statements (just to populate the cache) with 1000 tables shows 3k tps of internal reads reduction and 9.1% reduction of median instructions per op. So many tables were used to show resource impact, cache could be filled with other resource types to show the same improvement.

Backport: no, it's a new feature.
Fixes https://github.com/scylladb/scylladb/issues/7397
Fixes https://github.com/scylladb/scylladb/issues/3693
Fixes https://github.com/scylladb/scylladb/issues/2589
Fixes https://scylladb.atlassian.net/browse/SCYLLADB-147

Closes scylladb/scylladb#28078

* github.com:scylladb/scylladb:
  test: boost: add auth cache tests
  auth: add cache size metrics
  docs: conf: update permissions cache documentation
  auth: remove old permissions cache
  auth: use unified cache for permissions
  auth: ldap: add permissions reload to unified cache
  auth: add permissions cache to auth/cache
  auth: add service::revoke_all as main entry point
  auth: explicitly life-extend resource in auth_migration_listener
2026-02-18 12:03:20 +01:00
Alex
c44ad31d44 db/view: gate detached view-builder callbacks during shutdown
Detached migration callbacks (on_create_view, on_update_view, on_drop_view)
  can race with view_builder::drain() teardown.

  Add a lifetime gate to view_builder and wire callback launches through
  _ops_gate.hold() so each detached dispatch future is tracked until it
  completes (finally keeps the hold alive). During shutdown, drain()
  now waits for all tracked callback work with _ops_gate.close().

  This ensures drain does not proceed past callback lifetime while shutdown is in
  progress, and ignores only gate_closed_exception at callback entry as the
  expected shutdown path.
2026-02-18 11:56:41 +02:00
Calle Wilund
ab4e4a8ac7 commitlog: Always abort replenish queue on loop exit
Fixes #28678

If replenish loop exits the sleep condition, with an empty queue,
when "_shutdown" is already set, a waiter might get stuck, unsignalled
waiting for segments, even though we are exiting.

Simply move queue abort to always be done on loop exit.

Closes scylladb/scylladb#28679
2026-02-17 23:46:47 +02:00
Marcin Maliszkiewicz
a059798de9 docs: conf: update permissions cache documentation 2026-02-17 18:18:40 +01:00
Alex
75e25493c1 db:view: refactor on_update_view to use coroutine dispatcher
on_update_view() currently runs its serialized logic inline via with_semaphore()
  from a detached callback path, while create/drop already use dedicated async
  dispatchers.

  Refactor update handling to follow the same pattern:

  - add dispatch_update_view(sstring ks_name, sstring view_name)
  - move update logic into that coroutine
  - acquire the existing view-builder lock via get_or_adopt_view_builder_lock()
  - keep existing behavior for missing base/view state
  - keep background invocation semantics from on_update_view()

  This aligns update/create/drop flow and keeps async lifecycle handling and a first step to fix shutdown issue.
2026-02-15 18:50:32 +02:00
Patryk Jędrzejczak
e21ecf69de raft topology: make some assertions non-crashing
Some assertions in the Raft-based topology are likely to cause crashes of
multiple nodes due to the consistent nature of the Raft-based code. If the
failing assertion is executed in the code run by each follower (e.g., the code
reloading the in-memory topology state machine), then all nodes can crash. If
the failing assertion is executed only by the leader (e.g., the topology
coordinator fiber), then multiple consecutive group0 leaders will chain-crash
until there is no group0 majority.

Crashing multiple nodes is much more severe than necessary. It's enough to
prevent the topology state machine from making more progress. This will
naturally happen after throwing a runtime error. The problematic fiber will be
killed or will keep failing in a loop. Note that it should be safe to block
the topology state machine, but not the whole group0, as the topology state
machine is mostly isolated from the rest of group0.

We replace some occurrences of `on_fatal_internal_error` and `SCYLLA_ASSERT`
with `on_internal_error`. These are not all occurrences, as some fatal
assertions make sense, for example, in the bootstrap procedure.
2026-02-12 13:10:03 +01:00
Pavel Emelyanov
727f1be11c hint_sender: Switch to sender group on stop either
Currently sender only switches group for hints sending on start. It's
worth doing the same on stop too for consistency. There's nothing to
compete with at this point.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2026-02-09 08:54:51 +03:00
Tomasz Grabiec
41930c0176 tablets, config: Reduce migration concurrency to 2
Tablet migration keeps sstable snapshot during streaming, which may
cause temporary increase in disk utilization if compaction is running
concurrently. SStables compacted away are kept on disk until streaming
is done with them. The more tablets we allow to migrate concurrently,
the higher disk space can rise. When the target tablet size is
configured correcly, every tablet should own about 1% of disk
space. So concurrency of 4 shouldn't put us at risk. But target tablet
size is not chosen dynamically yet, and it may not be aligned with
disk capacity.

Also, tablet sizes can temporary grow above the target, up to 2x
before the split starts, and some more because splits take a while to
complete.

The reduce impact from this, reduce concurrency of
migation. Concurrency of 2 should still be enough to saturate
resources on the leaving shard.

Also, reducing concurrency means that load balancing is more
responsive to preemption. There will be less bandwidth sharing, so
scheduled migrations complete faster. This is important for scale-out,
where we bootstrap a node and want to start migrations to that new
node as soon as possible.

Refs scylladb/siren#15317
2026-02-06 00:42:19 +01:00
Tomasz Grabiec
39492596c2 config, tablets: Make tablet migration concurrency configurable
We're about to reduce it. It's better to not have it hard-coded in
case we change our mings again.
2026-02-06 00:42:18 +01:00
Michał Hudobski
6b9fcc6ca3 auth: add CDC streams and timestamps to vector search permissions
It turns out that the cdc driver requires permissions to two additional system tables. This patch adds them to VECTOR_SEARCH_INDEXING and modifies the unit tests. The integration with vector store was tested manually, integration tests will be added in vector-store repository in a follow up PR.

Fixes: SCYLLADB-522

Closes scylladb/scylladb#28519
2026-02-04 09:10:08 +01:00
Pavel Emelyanov
19ea05692c view_build_worker: Do not switch scheduling groups inside work_on_view_building_tasks
The handler appeared back in c9e710dca3. In this commit it performed the
"core" part of the task -- the do_build_range() method -- inside the
streaming sched group. The setup code looks seemingly was copied from the
view_builder::do_build_step() method and got the explicit switch of the
scheduling group.

The switch looks both -- justified and not. On one hand, it makes it
explict that the activity runs in the streaming scheduling group. On the
other hand, the verb already uses RPC index on 1, which is negotiated to
be run in streaming group anyway. On the "third hand", even though being
explicit the switch happens too late, as there exists a lot of other
activities performed by the handler that seems to also belong to the
same scheduling group, but which is not switched into explicitly.

By and large, it seems better to avoid the explicit switch and rely on
the RPC-level negotiation-based sched group switching.

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

Closes scylladb/scylladb#28397
2026-02-03 07:00:32 +02:00
Gleb Natapov
08268eee3f topology: disable force-gossip-topology-changes option
The patch marks force-gossip-topology-changes as deprecated and removes
tests that use it. There is one test (test_different_group0_ids) which
is marked as xfail instead since it looks like gossiper mode was used
there as a way to easily achieve a certain state, so more investigation
is needed if the tests can be fixed to use raft mode instead.

Closes scylladb/scylladb#28383
2026-02-02 09:56:32 +01:00
Patryk Jędrzejczak
68b105b21c db: virtual tables: add the rack column to cluster_status
`system.cluster_status` is missing the rack info compared to `nodetool status`
that is supposed to be equivalent. It has probably been an omission.

Closes scylladb/scylladb#28457
2026-02-01 20:36:53 +01:00
Botond Dénes
3158e9b017 doc: reorganize properties in config.cc and config.hh
This commit moves the "Ungrouped properties" category to the end of the
properties list. The properties are now published in the documentation,
and it doesn't look good if the list starts with ungrouped properties.

This patch was taken over from Anna Stuchlik <anna.stuchlik@scylladb.com>.

Closes scylladb/scylladb#28343
2026-01-29 11:27:42 +03:00
Pavel Emelyanov
937d008d3c Merge 'Clean up partition_snapshot_reader' from Botond Dénes
Move to `replica/`, drop `flat` from name and drop unused usages as well as unused includes.

Code cleanup, no backport

Closes scylladb/scylladb#28353

* github.com:scylladb/scylladb:
  replica/partition_snapshot_reader: remove unused includes
  partition_snapshot_reader: remove "flat" from name
  mv partition_snapshot_reader.hh -> replica/
2026-01-29 11:22:15 +03:00
Botond Dénes
482ffe06fd Merge 'Improve load shedding on the replica side' from Łukasz Paszkowski
When reads arrive, they have to wait for admission on the reader
concurrency semaphore. If the node is overloaded, the reads will
be queued. They can time out while in the queue, but will not time
out once admitted.

Once the shard is sufficiently loaded, it is possible that most
queued reads will time out, because the average time it takes to
for a queued read to be admitted is around that of the timeout.

If a read times out, any work we already did, or are about to do
on it is wasted effort. Therefore, the patch tries to prevent it
by checking if an admitted read has a chance to complete in time
and abort it if not. It uses the following criteria:

if read's remaining time <= read's timeout when arrived to the semaphore * live updateable preemptive_abort_factor;
the read is rejected and the next one from the wait list is considered.

Fixes https://github.com/scylladb/scylladb/issues/14909
Fixes: SCYLLADB-353

Backport is not needed. Better to first observe its impact.

Closes scylladb/scylladb#21649

* github.com:scylladb/scylladb:
  reader_concurrency_semaphore: Check during admission if read may timeout
  permit_reader::impl: Replace break with return after evicting inactive permit on timeout
  reader_concurrency_semaphore: Add preemptive_abort_factor to constructors
  config: Add parameters to control reads' preemptive_abort_factor
  permit_reader: Add a new state: preemptive_aborted
  reader_concurrency_semaphore: validate waiters counter when dequeueing a waiting permit
  reader_concurrency_semaphore: Remove cpu_concurrency's default value
2026-01-29 08:27:22 +02:00
Piotr Dulikowski
ec6a2661de Merge 'Keep view_builder background fiber in maintenance scheduling group' from Pavel Emelyanov
In fact, it's partially there already. When view_builder::start() is called is first calls initialization code (the start_in_background() method), then kicks do_build_step() that runs a background fiber to perform build steps. The starting code inherits scheduling group from main(). And the step fiber code needs to run itself in a maintenance scheduling group, so it explicitly grabs one via database->db_config.

This PR mainly gets rid of the call to database::get_streaming_scheduling_group() from do_build_step() as preparation to splitting the streaming scheduling group into parts (see SCYLLADB-351). To make it happen the do_build_step() is patched to inherit its scheduling group from view_builder::start() and the start() itself is called by main from maintenance scheduling group (like for other view building services).

New feature (nested scheduling group), not backporting

Closes scylladb/scylladb#28386

* github.com:scylladb/scylladb:
  view_builder: Start background in maintenance group
  view_builder: Wake-up step fiber with condition variable
2026-01-28 20:49:19 +01:00
Pavel Emelyanov
3ebd02513a view_builder: Start background in maintenance group
Currently view_builder::start() is called in default scheduling group.
Once it initializes itself, it wakes up the step fiber that explicitly
switches to maintenance scheduling group.

This explicit switch made sence before previous patch, when the fiber
was implemented as a serialized action. Now the fiber starts directly
from .start() method and can inherit scheduling group from it.

Said that, main code calls view_builder::start() in maintenance
scheduling group killing two birds with one stone. First, the step fiber
no longer needs borrow its scheduling group indirectly via database.
Second, the start_in_background() code itself runs in a more suitable
scheduling group.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2026-01-28 18:34:59 +03:00
Pavel Emelyanov
2439d27b60 view_builder: Wake-up step fiber with condition variable
View builder runs a background fiber that perform build steps. To kick
the fiber it uses serizlized action, but it's an overkill -- nobody
waits for the action to finish, but on stop, when it's joined.

This patch uses condition variable to kick the fiber, and starts it
instantly, in the place where serialized action was first kicked.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2026-01-28 18:34:58 +03:00
Łukasz Paszkowski
21348050e8 config: Add parameters to control reads' preemptive_abort_factor 2026-01-28 14:20:01 +01:00
Botond Dénes
ee631f31a0 Merge 'Do not export system keyspace from raft_group0_client' from Pavel Emelyanov
There are few places that use raft_group0_client as a way to get to system_keyspace. Mostly they can live without it -- either the needed reference is already at hand, or it's (ab)used to get to the database reference. The only place that really needs the system keyspace is the state merger code that needs last state ID. For that, the explicit helper method is added to group0_client.

Refining API between components, not backporting

Closes scylladb/scylladb#28387

* github.com:scylladb/scylladb:
  raft_group0_client: Dont export system keyspace
  raft_group0_client: Add and use get_last_group0_state_id()
  group0_state_machine: Call ensure_group0_sched() with data_dictionary
  view_building_worker: Use its own system_keyspace& reference
2026-01-28 13:24:32 +02:00
Emil Maskovsky
834961c308 db/view: add missing include for coroutine::all to fix build without precompiled headers
When building with `--disable-precompiled-header`, view.cc failed to
compile due to missing <seastar/coroutine/all.hh> include, which provides
`coroutine::all`.

The problem doesn't manifest when precompiled headers are used, which is
the default. So that's likely why it was missed by the CI.

Adding the explicit include fixes the build.

Fixes: scylladb/scylladb#28378
Ref: scylladb/scylladb#28093

No backport: This problem is only present in master.

Closes scylladb/scylladb#28379
2026-01-27 18:56:56 +01:00
Pavel Emelyanov
20a2b944df view_building_worker: Use its own system_keyspace& reference
Some code in the worker need to mess with system_keyspace&. While
there's a reference on it from the worker object, it gets one via
group0 -> group0_client, which is a bit an overkill.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2026-01-27 14:46:48 +03:00
Pavel Emelyanov
c61d855250 hints: Provide explicit scheduling group for hint_sender
Currently it grabs one from database, but it's not nice to use database
as config/sched-groups provider.

This PR passes the scheduling group to use for sending hints via manager
which, in turn, gets one from proxy via its config (proxy config already
carries configuration for hints manager). The group is initialized in
main.cc code and is set to the maintenance one (nowadays it's the same
as streaming group).

This will help splitting the streaming scheduling group into more
elaborated groups under the maintenance supergroup: SCYLLADB-351

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

Closes scylladb/scylladb#28358
2026-01-27 12:50:11 +02:00
Piotr Dulikowski
5d5e829107 Merge 'db: view: refactor usage and building of semaphore in create and drop views plus change continuation to co routine style' from Alex Dathskovsky
db: view: refactor semaphore usage in create/drop view paths
Refactor the construction and usage of semaphore units in the create and drop view flows.
The previous semaphore handling was hard to follow (as noted while working on https://github.com/scylladb/scylladb/pull/27929), so this change restructures unit creation and movement to follow a clearer and symmetric pattern across shards.

The semaphore usage model is now documented with a detailed in-code comment to make the intended behavior and invariants explicit.

As part of the refactor, the control flow is modernized by replacing continuation-based logic with coroutine-style code, improving readability and maintainability.

Fixes: https://scylladb.atlassian.net/browse/SCYLLADB-250

backport: not required, this is a refactor

Closes scylladb/scylladb#28093

* github.com:scylladb/scylladb:
  db: view: extend try/catch scope in handle_create_view_local The try/catch region is extended to cover step functions and inner helpers, which may throw or abort during view creation. This change is safe because we are just swolowing more parts that may throw due to semaphore abortion or any other abortion request, and doesnt change the logic
  db: view: refine create/drop coroutine signatures Refactor the create/drop coroutine interfaces to accept parameters as const references, enabling a clearer workflow and safer data flow.
  db: view: switch from continuations to coroutines Refactor the flow and style of create and drop view to use coroutines instead of continuations. This simplifies the logic, improves readability, and makes the code easier to maintain and extend. This commit also utilizes the get_view_builder_units function that was added in the previous commit. this commit also introduces a new alisasing for optional unit type for simpler and more readable functions that use this type
  db: view: introduce helper to acquire or reuse semaphore units Introduce a small helper that acquires semaphore units when needed or reuses units provided by the caller. This centralizes semaphore handling, simplifies the current logic, and enables refactoring the view create/drop path to a coroutine-based implementation instead of continuation-style code.
  db: view: add detailed comments on semaphore bookkeeping and serialized create/drop on shard 0
2026-01-26 17:16:01 +01:00
Botond Dénes
756837c5b4 partition_snapshot_reader: remove "flat" from name
The "flat" migration is long done, this distinction is no longer
meaningful.
2026-01-26 16:52:46 +02:00
Botond Dénes
9d1933492a mv partition_snapshot_reader.hh -> replica/
The partition snapshot lives in mutation/, however mutation/ is a lower
level concept than a mutation reader. The next best place for this
reader is the replica/ directory, where the memtable, its main user,
also lives.

Also move the code to the replica namespace.

test/boost/mvcc_test.cc includes this header but doesn't use anything
from it. Instead of updating the include path, just drop the unused
include.
2026-01-26 16:52:08 +02:00
Alex
954d18903e db: view: extend try/catch scope in handle_create_view_local
The try/catch region is extended to cover step functions and inner helpers,
which may throw or abort during view creation.
This change is safe because we are just swolowing more parts that may throw due to semaphore abortion
or any other abortion request, and doesnt change the logic
2026-01-26 13:10:37 +02:00
Alex
2c3ab8490c db: view: refine create/drop coroutine signatures
Refactor the create/drop coroutine interfaces to accept parameters as
const references, enabling a clearer workflow and safer data flow.
2026-01-26 13:10:34 +02:00
Alex
114f88cb9b db: view: switch from continuations to coroutines
Refactor the flow and style of create and drop view to use coroutines instead of continuations.
This simplifies the logic, improves readability, and makes the code
easier to maintain and extend. This commit also utilizes the get_view_builder_units function that was added in the previous commit.
this commit also introduces a new alisasing for optional unit type for simpler and more readable functions that use this type
2026-01-26 13:08:24 +02:00
Alex
87c1c6f40f db: view: introduce helper to acquire or reuse semaphore units
Introduce a small helper that acquires semaphore units when needed or
reuses units provided by the caller.
This centralizes semaphore handling, simplifies the current logic, and
enables refactoring the view create/drop path to a coroutine-based
implementation instead of continuation-style code.
2026-01-26 13:03:26 +02:00
Alex
1aadedc596 db: view: add detailed comments on semaphore bookkeeping and serialized create/drop on shard 0 2026-01-25 14:29:09 +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
Botond Dénes
c4c2f87be7 Merge 'db: fail reads and writes with local consistency level to a DC with RF=0' from null
When read or write operations are performed on a DC with RF=0 with LOCAL_QUORUM
or LOCAL_ONE consistency level, Cassandra throws `Unavailable` exception.
Scylla allowed such read operations and failed write operations with a cryptic:
"broken promise" error. This occured because the initial availability
check passed (quorum of 0 requires 0 replicas), but execution failed
later when no replicas existed to process the mutation.

This patch adds an explicit RF=0 validation for LOCAL_ONE and LOCAL_QUORUM that
throws before attempting operation execution.

The change also requires `test_query_dc_with_rf_0_does_not_crash_db` to be
upgraded. This testcase was asserting somewhat similar scenario, but wasn't
taking into account the whole matrix of combinations:
- scenarios: successful vs unsuccesful operation outcome
- local consistency levels: LOCAL_QUORUM & LOCAL_ONE
- operations: SELECT (read) & INSERT (write)

and so it's been extended to cover both the pre-existing and the current issues
and the whole matrix of combinations.

Fixes: scylladb/scylladb#27893

A minor change, no need to backport.

Closes scylladb/scylladb#27894

* github.com:scylladb/scylladb:
  db: fail reads and writes with local consistencty level to a DC with RF=0
  db: consistency_level: split `local_quorum_for()`
  db: consistency_level: fix nrs -> nts abbreviation
2026-01-23 12:36:20 +02:00
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
Patryk Jędrzejczak
67045b5f17 Merge 'raft_topology, tablets: Drain tablets in parallel with other topology operations' from Tomasz Grabiec
Allows other topology operations to execute while tablets are being
drained on decommission. In particular, bootstrap on scale-out. This
is important for elasticity.

Allows multiple decommission/removenode to happen in parallel, which
is important for efficiency.

Flow of decommission/removenode request:
  1) pending and paused, has tablet replicas on target node.
     Tablet scheduler will start draining tablets.
  2) No tablets on target node, request is pending but not paused
  3) Request is scheduled, node is in transition
  4) Request is done

Nodes are considered draining as soon as there is a leave or remove
request on them. If there are tablet replicas present on the target
node, the request is in a paused state and will not be picked by
topology coordinator. The paused state is computed from topology state
automatically on reload.

When request is not paused, its execution starts in
write_both_read_old state. The old tablet_draining state is not
entered (it's deprecated now).

Tablet load balancing will yield the state machine as soon as some
request is no longer paused and ready to be scheduled, based on
standard preemption mechanics.

Fixes #21452

Closes scylladb/scylladb#24129

* https://github.com/scylladb/scylladb:
  docs: Document parallel decommission and removenode and relevant task API
  test: Add tests for parallel decommission/removenode
  test: util: Introduce ensure_group0_leader_on()
  test: tablets: Check that there are no migrations scheduled on draining nodes
  test: lib: topology_builder: Introduce add_draining_request()
  topology_coordinator, tablets: Fail draining operations when tablet migration fails due to critical disk utilization
  tablets: topology_coordinator: Refactor to propagate reason for migration rollback
  tablet_allocator: Skip co-location on draining nodes
  node_ops: task_manager_module: Populate entity field also for active requests
  tasks: node_ops: Put node id in the entity field
  tasks, node_ops: Unify setting of task_stats in get_status() and get_stats()
  topology: Protect against empty cancelation reason
  tasks, topology: Make pending node operations abortable
  doc: topology-over-raft.md: Fix diagram for replacing, tablet_draining is not engaged
  raft_topology, tablets: Drain tablets in parallel with other topology operations
  virtual_tables: Show draining and excluded fields in system.cluster_status and system.load_by_node
  locator: topology: Add "draining" flag to a node
  topology_coordinator: Extract generate_cancel_request_update()
  storage_service: Drop dependency in topology_state_machine.hh in the header
  locator: Extract common code in assert_rf_rack_valid_keyspace()
  topology_coordinator, storage_service: Validate node removal/decommission at request submission time
2026-01-22 13:06:53 +01:00
Piotr Smaron
d4c28690e1 db: fail reads and writes with local consistencty level to a DC with RF=0
When read or write operations are performed on a DC with RF=0 with LOCAL_QUORUM
or LOCAL_ONE consistency level, Cassandra throws `Unavailable` exception.
Scylla allowed such read operations and failed write operations with a cryptic:
"broken promise" error. This occured because the initial availability
check passed (quorum of 0 requires 0 replicas), but execution failed
later when no replicas existed to process the mutation.

This patch adds an explicit RF=0 validation for LOCAL_ONE and LOCAL_QUORUM that
throws before attempting operation execution.

The change also requires `test_query_dc_with_rf_0_does_not_crash_db` to be
upgraded. This testcase was asserting somewhat similar scenario, but wasn't
taking into account the whole matrix of combinations:
- scenarios: successful vs unsuccesful operation outcome
- local consistency levels: LOCAL_QUORUM & LOCAL_ONE
- operations: SELECT (read) & INSERT (write)

and so it's been extended to cover both the pre-existing and the current issues
and the whole matrix of combinations.

Fixes: scylladb/scylladb#27893
2026-01-22 12:49:45 +01:00
Piotr Smaron
9475659ae8 db: consistency_level: split local_quorum_for()
The core of `local_quorum_for()` has been extracted to
`get_replication_factor_for_dc()`, which is going to be used later,
while `local_quorum_for()` itself has been recreated using the exracted
part.
2026-01-22 12:49:23 +01:00
Piotr Smaron
0b3ee197b6 db: consistency_level: fix nrs -> nts abbreviation
`network_topology_strategy` was abbreviated with `nrs`, and not `nts`. I
think someone incorrectly assumed it's 'network Replication strategy', hence
nrs.
2026-01-22 12:48:37 +01:00
Botond Dénes
7d2e6c0170 Merge 'config: add enforce_rack_list option' from Aleksandra Martyniuk
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.

Mark rf_rack_valid_keyspaces as deprecated.

Fixes: https://github.com/scylladb/scylladb/issues/26399.

New feature; no backport needed

Closes scylladb/scylladb#28084

* github.com:scylladb/scylladb:
  test: add test for enforce_rack_list option
  db: mark rf_rack_valid_keyspaces as deprecated
  config: add enforce_rack_list option
  Revert "alternator: require rf_rack_valid_keyspaces when creating index"
2026-01-22 10:27:35 +02:00
Benny Halevy
91df129e21 snapshot: add basic support for snapshot ttl in manifest.json
Store the snapshot `created_at` time and an optional
`expires_at` time.

Fixes SCYLLADB-189

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
Botond Dénes
4281d18c2e Merge 'schema: Apply sstable_compression_user_table_options to CQL aux and Alternator tables' from Nikos Dragazis
In PR 5b6570be52 we introduced the config option `sstable_compression_user_table_options` to allow adjusting the default compression settings for user tables. However, the new option was hooked into the CQL layer and applied only to CQL base tables, not to the whole spectrum of user tables: CQL auxiliary tables (materialized views, secondary indexes, CDC log tables), Alternator base tables, Alternator auxiliary tables (GSIs, LSIs, Streams).

This gap also led to inconsistent default compression algorithms after we changed the option’s default algorithm from LZ4 to LZ4WithDicts (adf9c426c2).

This series introduces a general “schema initializer” mechanism in `schema_builder` and uses it to apply the default compression settings uniformly across all user tables. This ensures that all base and aux tables take their default compression settings from config.

Fixes #26914.

Backport justification: LZ4WithDicts is the new default since 2025.4, but the config option exists since 2025.2. Based on severity, I suggest we backport only to 2025.4 to maintain consistency of the defaults.

Closes scylladb/scylladb#27204

* github.com:scylladb/scylladb:
  db/config: Update sstable_compression_user_table_options description
  schema: Add initializer for compression defaults
  schema: Generalize static configurators into schema initializers
  schema: Initialize static properties eagerly
  db: config: Add accessor for sstable_compression_user_table_options
  test: Check that CQL and Alternator tables respect compression config
2026-01-22 06:50:48 +02:00
Petr Gusev
998ee5b7fb system_keyspace: disable tablet_balancing for strongly_consistent_tables
We don't yet support tablet balancing for strongly consistent tables.
2026-01-21 14:56:00 +01:00
Botond Dénes
a53f989d2f db/row_cache: make_nonpopulating_reader(): pass cache tracker to snapshot
The API contract in partition_version.hh states that when dealing with
evictable entries, a real cache tracker pointer has to be passed to all
methods that ask for it. The nonpopulating reader violates this, passing
a nullptr to the snapshot. This was observed to cause a crash when a
concurrent cache read accessed the snapshot with the null tracker.

A reproducer is included which fails before and passes after the fix.

Fixes: #26847

Closes scylladb/scylladb#28163
2026-01-20 12:34:37 +01:00
Aleksandra Martyniuk
7dc371f312 db: mark rf_rack_valid_keyspaces as deprecated
Mark rf_rack_valid_keyspaces option as deprecated. User should
use enforce_rack_list option instead.

The option can still be used and it does not change it's behavior.

Docs is updated accordingly.
2026-01-20 09:58:57 +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