Commit Graph

1120 Commits

Author SHA1 Message Date
Tomasz Grabiec
df949dc506 Merge 'topology_coordinator: make cleanup reliable on barrier failures' from Łukasz Paszkowski
Fix a subtle but damaging failure mode in the tablet migration state machine: when a barrier fails, the follow-up barrier is triggered asynchronously, and cleanup can get skipped for that iteration. On the next loop, the original failure may no longer be visible (because the failing node got excluded), so the tablet can incorrectly move forward instead of entering `cleanup_target`.

To make cleanup reliable this PR:

Adds an additional “fallback cleanup” stage

- `write_both_read_old_fallback_cleanup`

that does not modify read/write selectors. This stage is safe to enter immediately after a barrier failure, and it funnels the tablet into cleanup with the required barriers.

Avoids changing both read and write selectors in a single step transitioning from `write_both_read_new` to `cleanup_target`. The fallback path updates selectors in a safe order: read first, then write.

Allows a direct no-barrier transition from `allow_write_both_read_old` to `cleanup_target` after failure, because in that specific case `cleanup_target` doesn’t change selectors and the hop is safe.

No need for backport. It's an improvement. Currently, tablets transition to `cleanup_target` eventually via failed streaming.

Closes scylladb/scylladb#28169

* github.com:scylladb/scylladb:
  topology_coordinator: add write_both_read_old_fallback_cleanup state
  topology_coordinator: allow cleanup_target transition from streaming/rebuild_repair without barrier
  topology_coordinator: allow cleanup_target transition without barrier after failure in write_both_read_old
  topology_coordinator: allow cleanup_target transition without barrier after failure in allow_write_both_read_old
2026-01-28 13:33:39 +01:00
Łukasz Paszkowski
f06094aa95 topology_coordinator: add write_both_read_old_fallback_cleanup state
Yet another barrier-failure scenario exists in the `write_both_read_new`
state. When the barrier fails, the tablet is expected to transition
to `cleanup_target`, but because barrier execution is asynchronous,
the cleanup transition can be skipped entirely and the tablet may
continue forward instead.

Both `write_both_read_new` and `cleanup_target` modify read and write
selectors. In this situation, a barrier is required, and transitioning
directly between these states without one is unsafe.

Introduce an intermediate `write_both_read_old_fallback_cleanup`
state that modifies only a read selector and can be entered without
a barrier (there is no need to wait for all nodes to start using the
"new" read selector). From there, the tablet can proceed to `cleanup_target`,
where the required barriers are enforced.

This also avoids changing both selectors in a single step. A direct
transition from `write_both_read_new` to `cleanup_target` updates
both selectors at once, which can leave coordinators using the old
selector for writes and the new selector for reads, causing reads to
miss preceding writes.

By routing through the fallback state, selectors are updated in
order—read first, then write—preserving read-after-write correctness.
2026-01-26 13:14:37 +01:00
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
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
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
Petr Gusev
dc4896b69b tablets: generate raft group_id-s for new table
We assign shard to zero because raft is currently only supported on the
zero shard.
2026-01-21 14:56:00 +01:00
Petr Gusev
6dd74be684 tablet_replication_strategy: add consistency field
This commit adds a `consistency` field to `tablet_replication_strategy`.
In upcoming commits we'll use this field to determine if a
`raft_group_id` should be generated for a new table.
2026-01-21 14:56:00 +01:00
Petr Gusev
53f93eb830 tablets: add raft_group_id
Add a `raft_group_id` column to `system.tablets` and to the `tablet_map`
class. The column is populated only when the
`strongly_consistent_tables` feature is enabled.

This feature is currently disabled by default and is enabled only when
the user sets the `STRONGLY_CONSISTENT_TABLES` experimental flag.

The `raft_group_id` column is added to `system.tablets` only when this
flag is set. This allows the schema to evolve freely while the feature
is experimental, without requiring complex migrations.
2026-01-21 14:56:00 +01:00
Raphael S. Carvalho
d16f9c821d Revert "api: storage_service/tablets/repair: disable incremental repair by default"
This reverts commit c8cff94a5a.

Re-enabling incremental repair on master with "Aborting on shard 0 during
scaleout + repair #26041" and "Failure to attach sstables in streaming consumer
leaves sealed sstables on disk #27414" fixed.

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

Closes scylladb/scylladb#28120
2026-01-21 08:50:13 +02:00
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
Tomasz Grabiec
a009644c7d raft_topology, tablets: Drain tablets in parallel with other topology operations
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.

The test case test_explicit_tablet_movement_during_decommission is
removed. It verifies that tablet move API works during tablet draining
transition. After this PR, we no longer enter this transition, so the
test doesn't work. It loses its purpose, because movement during
normal tablet balancing is not special and tested elsewhere.
2026-01-18 15:36:05 +01:00
Tomasz Grabiec
1c2e47e059 locator: topology: Add "draining" flag to a node
They are being drained of tablet replicas, tablet scheduler works to
move replicas away from such nodes. This state is set at the
beginning of decommission and removenode operations.
2026-01-18 15:36:04 +01:00
Tomasz Grabiec
a24c3fc229 locator: Extract common code in assert_rf_rack_valid_keyspace() 2026-01-18 15:36:04 +01:00
Tomasz Grabiec
eef798d84f Merge 'Distribute data evenly among primary replicas during restore' from Robert Bindar
Most likely 817fdad uncovered the fact that our choice of primary replica was resonating with tablet allocation and we were ending up picking the same replica as primary within a scope instead of rotating primaryship among all replicas in the scope.
This created situations where for instance, restoring into a 9 nodes with primary_replica_only=true would put all data into 3 nodes, leaving the other 6 unused. The balancing of the dataset was performed by the subsequent repair step.

This PR fixes this by changing the formula for picking up the primary replica out of a set of eligible replicas from within the passed scope.
The PR also extends the testing scenarios in `test_backup.py` so we get to run restore for a set of topologies, for all combinations of scope, primary_replica_only and min_tablet_counts.
Most of the work was done by @bhalevy [here](https://github.com/scylladb/scylladb/compare/master...bhalevy:scylla:load-balance-primary-replica), this PR just splitted it and did touchups here and there.

Fixes #27281

Closes scylladb/scylladb#27397

* github.com:scylladb/scylladb:
  test: reduce dataset and number of test cases or debug builds
  test: bump repair timeout up, it's sometimes not enough in CI
  test: refactor test_refresh.py to match test_restore_with_streaming_scopes.
  test: extend test_restore_with_streaming_scopes
  test: Adjust test_restore_primary_replica_different_dc_scope_all
  test: Refactor restoring code in test_backup to match SM pattern
  test: add check_mutation_replicas calls after fresh creation of dataset
  test: extend create_dataset to accept consistency_level
  test: refactor check_mutation_replicas so it's more readable
  test: make create_dataset async and refactor so it's configurable
  test: use defaultdict in collect_mutations
  test: add log marks to facilitate reusing server for restore
  locator: tablets: Distribute data evenly among primary replicas during restore
2026-01-14 18:57:55 +01:00
Robert Bindar
d88036db48 locator: tablets: Distribute data evenly among primary replicas during restore
Most likely 817fdad uncovered the fact that our choice of
primary replica was resonating with tablet allocation and we were ending up
picking the same replica as primary within a scope instead of rotating
primaryship among all replicas in the scope.
This created situations where for instance, restoring into a 9 nodes cluster
with primary_replica_only=true would put all data into 3 nodes, leaving
the other 6 unused. The balancing of the dataset was performed by the
subsequent repair step.

split from bhalevy/load-balance-primary-replica

Fixes #27281

Signed-off-by: Robert Bindar <robert.bindar@scylladb.com>
2026-01-13 11:44:20 +02:00
Botond Dénes
04b8f72946 Merge 'repair: Implement auto repair for tablet repair' from Asias He
repair: Implement auto repair for tablet repair

This patch implements the basic auto repair support for tablet repair.

It was decided to add no per table configuration for the initial
implementation, so two scylla yaml config options are introduced to set
the default auto repair configs for all the tablet tables.

- auto_repair_enabled_default

Set true to enable auto repair for tablet tables by default. The value
will be overridden by the per keyspace or per table configuration which
is not implemented yet.

- auto_repair_threshold_default_in_seconds

Set the default time in seconds for the auto repair threshold for tablet
tables. If the time since last repair is bigger than the configured
time, the tablet is eligible for auto repair. The value will be
overridden by the per keyspace or per table configuration which is not
implemented yet.

The following metrcis are added:

- auto_repair_needs_repair_nr

The number of tablets with auto repair enabled that needs repair

- auto_repair_enabled_nr

The number of tablets with auto repair enabled

The metrics are useful to tell if auto repair is falling behind.

In the future, more auto repair scheduling will be added, e.g.,
scheduling based on the repaired and unrepaired sstable set size,
tombstone ratio and so on, in addition to the time based scheduling.

Fixes SCYLLADB-99

New feature. No backport.

Closes scylladb/scylladb#27534

* github.com:scylladb/scylladb:
  topology_coordinator: Add metrics for tablet repair
  repair: Implement auto repair for tablet repair
2026-01-12 14:16:01 +02:00
Asias He
7ba7b25bdd repair: Implement auto repair for tablet repair
This patch implements the basic auto repair support for tablet repair.

It was decided to add no per table configuration for the initial
implementation, so two scylla yaml config options are introduced to set
the default auto repair configs for all the tablet tables.

- auto_repair_enabled_default

Set true to enable auto repair for tablet tables by default. The value
will be overridden by the per keyspace or per table configuration which
is not implemented yet.

- auto_repair_threshold_default_in_seconds

Set the default time in seconds for the auto repair threshold for tablet
tables. If the time since last repair is bigger than the configured
time, the tablet is eligible for auto repair. The value will be
overridden by the per keyspace or per table configuration which is not
implemented yet.

The following metrcis are added:

- auto_repair_needs_repair_nr

The number of tablets with auto repair enabled that needs repair

- auto_repair_enabled_nr

The number of tablets with auto repair enabled

The metrics are useful to tell if auto repair is falling behind.

In the future, more auto repair scheduling will be added, e.g.,
scheduling based on the repaired and unrepaired sstable set size,
tombstone ratio and so on, in addition to the time based scheduling.

Fixes SCYLLADB-99
2026-01-09 16:11:39 +08:00
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
Łukasz Paszkowski
62313a6264 load_sketch: Allow populating load_sketch with normalized current load
Currently, tablet allocation intentionally ignores current load (
introduced by the commit #1e407ab) which could cause identical shard
selection when allocating a small number of tablets in the same topology.
When a tablet allocator is asked to allocate N tablets (where N is smaller
than the number of shards on a node), it selects the first N lowest shards.
If multiple such tables are created, each allocator run picks the same
shards, leading to tablet imbalance across shards.

This change initializes the load sketch with the current shard load,
scaled into the [0,1] range, ensuring allocation still remains even
while starting from globally least-loaded shards.

Fixes https://github.com/scylladb/scylladb/issues/27620

Closes scylladb/scylladb#27802
2026-01-07 11:49:01 +01:00
Ferenc Szili
621cb19045 load_sketch: use tablet sizes in load computation
This commit changes load_sketch so that it computes node and shard load
based on tablet sizes instead of tablet count.
2025-12-27 10:37:23 +01:00
Ferenc Szili
1c9ec9a76d load_stats: add get_tablet_size_in_transition()
This patch adds a method to load_stats which searches for the tablet
size during tablet transition. In case of tablet migration, the tablet
will be searched on the leaving replica, and during rebuild we will
return the average tablet size of the pending replicas.
2025-12-27 10:37:23 +01:00
Michael Litvak
07d85af433 locator: extend rf-rack validation for rack lists
Extend the RF-rack validation in `assert_rf_rack_valid_keyspace` to
validate rack-list-based replication as well. Previously, validation was
done only for numeric replication.

If the replication is based on a rack list, we validate that all racks
that are required for replication are present in the topology rack map.
If some rack is needed for replication but is missing, or it doesn't
have normal token owner nodes, the validation fails with an error.
2025-12-22 09:14:30 +01:00
Michael Litvak
a738905a4b locator: fix rf-rack validation during node join/remove
If a keyspace is created while a node is joining or being removed, it could
break the rf-rack invariant. For example:
1. We have 3 nodes in 3 racks, no keyspaces
2. A new node starts to join in a new rack - passes validation because
   there are no keyspaces
3. Create a keyspace with rf=3 - passes validation because the joining
   node is not a normal token owner yet
4. The new node becomes a normal token owner
5. The rf-rack invariant is broken. We have rf=3 and 4 racks

To fix this, we change the rf-rack check to consider a node as a token
owner if it's either a normal token owner or it has bootstrap tokens and
is about to become a normal token owner.

Now the condition can't be broken. Consider keyspace creation at
different stages of adding a node in our example:
* Before the node is assigned bootstrap tokens: the node is not
  considered. We can create a keyspace with rf=3 as if the node doesn't
  exist, and then node join will fail in the group0 operation that
  assigns bootstrap tokens, because during this operation we check
  rf-rack validity.
* Assigning bootstrap tokens is a single group0 operation that is
  serialized with keyspace creation. During this operation we check that
  adding the node as a token owner will maintain rf-rack validity for all
  keyspaces.
* After the node is assigned bootstrap tokens and until it becomes a
  normal token owner: it is considered as a transitioning token owner by
  the rf-rack check and the rack is considered a transitioning rack. We
  can't count the rack as a normal rack because the node join may still
  fail and rollback. Trying to create a keyspace with either rf=3 or
  rf=4 will fail because we can end up with either 3 or 4 racks.

Similarly, when removing a node, we validate that removing the node will
maintain rf-rack validity in the same group0 operation that changes the
node state to removing/decommissioning, after which the node becomes a
leaving endpoint, and it's not considered a normal token owner anymore
for the rf-rack check.
2025-12-22 09:14:30 +01:00
Michael Litvak
9e1f78d162 locator: extend rf-rack validation functions
Extend the locator function assert_rf_rack_valid_keyspace to accept
arbitrary topology dc-rack maps and nodes instead of using the current
token metadata.

This allows us to add a new variant of the function that checks rf-rack
validity given a topology change that we want to apply. we will use it
to check that rf-rack validity will be maintained before applying the
topology change.

The possible topology changes for the check are node add and node remove
/ decommission. These operations can change the number of normal racks -
if a new node is added to a new rack, or the last node is removed from a
rack.
2025-12-22 09:14:29 +01:00
Michael Litvak
de1bb84fca db: enforce rf-rack-validity for keyspaces with views
Extend the RF-rack-validity enforcement to keyspaces that have views,
regardless of the option `rf_rack_valid_keyspaces`.

Previously, RF-rack-validity was enforced when `rf_rack_valid_keyspaces`
was set for all keyspaces. Now we want to allow creating MVs in tablet
keyspaces that are RF-rack-valid and enforce the RF-rack-validity even
if the config option is not set.
2025-12-22 09:13:49 +01:00
Dawid Mędrek
1e14c08eee locator/token_metadata: Remove get_host_id()
The function is declared, but it's not defined or used anywhere.

Closes scylladb/scylladb#27374
2025-12-15 10:36:52 +01:00
Benny Halevy
c8cff94a5a api: storage_service/tablets/repair: disable incremental repair by default
Change the default incremental_mode to `disabled` due to
https://github.com/scylladb/scylladb/issues/26041 and
https://github.com/scylladb/scylladb/issues/27414

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2025-12-11 14:25:21 +02:00
Tomasz Grabiec
d6c14de380 Merge 'locator/node: include _excluded in missing places' from Patryk Jędrzejczak
We currently ignore the `_excluded` field in `node::clone()` and the verbose
formatter of `locator::node`. The first one is a bug that can have
unpredictable consequences on the system. The second one can be a minor
inconvenience during debugging.

We fix both places in this PR.

Fixes https://scylladb.atlassian.net/browse/SCYLLADB-72

This PR is a bugfix that should be backported to all supported branches.

Closes scylladb/scylladb#27265

* github.com:scylladb/scylladb:
  locator/node: include _excluded in verbose formatter
  locator/node: preserve _excluded in clone()
2025-11-26 18:29:59 +01:00
Patryk Jędrzejczak
287c9eea65 locator/node: include _excluded in verbose formatter
It can be helpful during debugging.
2025-11-26 13:26:17 +01:00
Patryk Jędrzejczak
4160ae94c1 locator/node: preserve _excluded in clone()
We currently ignore the `_excluded` field in `clone()`. Losing
information about exclusion can have unpredictable consequences. One
observed effect (that led to finding this issue) is that the
`/storage_service/nodes/excluded` API endpoint sometimes misses excluded
nodes.
2025-11-26 13:26:11 +01:00
Patryk Jędrzejczak
cc273e867d Merge 'fix notification about expiring erm held for to long' from Gleb Natapov
Commit 6e4803a750 broke notification about expired erms held for too long since it resets the tracker without calling its destructor (where notification is triggered). Fix the assign operator to call the destructor like it should.

Fixes https://github.com/scylladb/scylladb/issues/27141

Closes scylladb/scylladb#27140

* https://github.com/scylladb/scylladb:
  test: test that expired erm that held for too long triggers notification
  token_metadata: fix notification about expiring erm held for to long
2025-11-26 12:59:00 +01:00
Gleb Natapov
9f97c376f1 token_metadata: fix notification about expiring erm held for to long
Commit 6e4803a750 broke notification about expired erms held for too
long since it resets the tracker without calling its destructor (where
notification is triggered). Fix assign operator to call destructor.
2025-11-25 13:35:24 +02:00
Radosław Cybulski
d589e68642 Add precompiled headers to CMakeLists.txt
Add precompiled header support to CMakeLists.txt and configure.py -
it improves compilation time by approximately 10%.

New header `stdafx.hh` is added, don't include it manually -
the compiler will include it for you. The header contains includes from
external libraries used by Scylla - seastar, standard library,
linux headers and zlib.

The feature is enabled by default, use CMake option `Scylla_USE_PRECOMPILED_HEADER`
or configure.py --disable-precompiled-header to disable.

The feature should be disabled, when trying to check headers - otherwise
you might get false negatives on missing includes from seastar / abseil and so on.

Note: following configuration needs to be added to ccache.conf:

    sloppiness = pch_defines,time_macros,include_file_mtime,include_file_ctime

Closes scylladb/scylladb#26617
2025-11-21 12:27:41 +02:00
Asias He
d51b1fea94 tablets: Allow tablet merge when repair tasks exist
Currently we do not allow tablet merge if either of the tablets contain
a tablet repair request. This could block the tablet merge for a very
long time if the repair requests could not be scheduled and executed.

We can actually merge the repair tasks in most of the cases. This is
because most of the time all tablets are requested to be repaired by a
single API request, so they share the same task_id, request_type and
other parameters. We can merge the repair task info and executes the
repair after the merge.  If they do not share the task info, we could
not merge and have to wait for the repair before merge, which is both
rare and ok.

Another case is that one of the tablet has a repair task info (t1) while
the other tablet (t2) does not have, it is possible the t2 has finished
repair by the same repair request or t2 is not requested to be repaired
at all. We allow merge in this case too to avoid blocking the tablet
merge, with the price of reparing a bit more.

Fixes #26844

Closes scylladb/scylladb#26922
2025-11-20 16:01:23 +01:00
Pavel Emelyanov
f47f2db710 Merge 'Support local primary-replica-only for native restore' from Robert Bindar
This PR extends the restore API so that it accepts primary_replica_only as parameter and it combines the concepts of primary-replica-only with scoped streaming so that with:
- `scope=all primary_replica_only=true` The restoring node will stream to the global primary replica only
- `scope=dc primary_replica_only=true` The restoring node will stream to the local primary replica only.
- `scope=rack primary_replica_only=true` The restoring node will stream only to the primary replica from within its own rack (with rf=#racks, the restoring node will stream only to itself)
- `scope=node primary_replica_only=true` is not allowed, the restoring node will always stream only to itself so the primary_replica_only parameter wouldn't make sense.

The PR also adjusts the `nodetool refresh` restriction on running restore with both primary_replica_only and scope, it adds primary_replica_only to `nodetool restore` and it adds cluster tests for primary replica within scope.

Fixes #26584

Closes scylladb/scylladb#26609

* github.com:scylladb/scylladb:
  Add cluster tests for checking scoped primary_replica_only streaming
  Improve choice distribution for primary replica
  Refactor cluster/object_store/test_backup
  nodetool restore: add primary-replica-only option
  nodetool refresh: Enable scope={all,dc,rack} with primary_replica_only
  Enable scoped primary replica only streaming
  Support primary_replica_only for native restore API
2025-11-13 12:11:18 +03:00
Tomasz Grabiec
10b893dc27 Merge 'load_stats: fix bug in migrate_tablet_size()' from Ferenc Szili
`topology_cooridinator::migrate_tablet_size()` was introduced in 10f07fb95a. It has a bug where the has_tablet_size() lambda always returns false because of bad comparison of iterators after a table and tablet search:

```
if (auto table_i = tables.find(gid.table); table_i != tables.find(gid.table)) {
    if (auto size_i = table_i->second.find(trange); size_i != table_i->second.find(trange)) {
```

This change also fixes a problem where the `migrate_tablet_size()` would crash with a `std::out_of_range` if the pending node was not present in load_stats.

This change fixes these two problems and moves the functionality into a separate method of `load_stats`. It also adds tests for the new method.

A version containing this bug has not been released yet, so no backport is needed.

Closes scylladb/scylladb#26946

* github.com:scylladb/scylladb:
  load_stats: add test for migrate_tablet_size()
  load_stats: fix problem with tablet size migration
2025-11-12 23:48:37 +01:00
Ferenc Szili
b77ea1b8e1 load_stats: fix problem with tablet size migration
This patch fixes a bug with tablet size migration in load_stats.
has_tablet_size() lambda in topology_coordinator::migrate_tablet_size()
was returning false in all cases due to incorrect search iterator
comparison after a table and tablet saeach.

This change moves load_stats migrate_tablet_sizes() functionaility
into a separate method of load_stats.
2025-11-11 14:26:09 +01:00
Benny Halevy
a290505239 utils: stall_free: add dispose_gently
dispose_gently consumes the object moved to it,
clearing it gently before it's destroyed.

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>

Closes scylladb/scylladb#26356
2025-11-11 12:20:18 +02:00
Robert Bindar
817fdadd49 Improve choice distribution for primary replica
I noticed during tests that `maybe_get_primary_replica`
would not distribute uniformly the choice of primary replica
because `info.replicas` on some shards would have an order whilst
on others it'd be ordered differently, thus making the function choose
a node as primary replica multiple times when it clearly could've
chosen a different nodes.

This patch sorts the replica set before passing it through the
scope filter.

Signed-off-by: Robert Bindar <robert.bindar@scylladb.com>
2025-11-11 09:18:01 +02:00
Avi Kivity
d458dd41c6 Merge 'Avoid input_/output_stream-s default initialization and move-assignment' from Pavel Emelyanov
Recent seastar update deprecated in/out streams usage pattern when a stream is default constructed early and them move-assigned with the proper one (see scylladb/seastar#3051). This PR fixes few places in Scylla that still use one.

Adopting newer seastar API, no need to backport

Closes scylladb/scylladb#26747

* github.com:scylladb/scylladb:
  commitlog: Remove unused work::r stream variable
  ec2_snitch: Fix indentation after previous patch
  ec2_snitch: Coroutinize the aws_api_call_once()
  sstable: Construct output_stream for data instantly
  test: Don't reuse on-stack input stream
2025-10-31 21:22:41 +02:00
Tomasz Grabiec
1c0d847281 Merge 'load_balancer: load_stats reconcile after tablet migration and table resize' from Ferenc Szili
This change adds the ability to move tablets sizes in load_stats after a tablet migration or table resize (split/merge). This is needed because the size based load balancer needs to have tablet size data which is as accurate as possible, in order to work on fresh tablet size distribution and issue correct tablet migrations.

This is the second part of the size based load balancing changes:

- First part for tablet size collection via load_stats: #26035
- Second part reconcile load_stats: #26152
- The third part for load_sketch changes: #26153
- The fourth part which performs tablet load balancing based on tablet size: #26254

This is a new feature and backport is not needed.

Closes scylladb/scylladb#26152

* github.com:scylladb/scylladb:
  load_balancer: load_stats reconcile after tablet migration and table resize
  load_stats: change data structure which contains tablet sizes
2025-10-31 09:58:25 +01:00
Tomasz Grabiec
28f6bdc99b cql3: ks_prop_defs: Expand numeric RF to rack list
Auto-exands numeric RF in CREATE/ALTER KEYSPACE statements for
new DCs specified in the statement.

Doesn't auto-expand existing options, as the rack choice may not be in
line with current replica placement. This requires co-locating tablet
replicas, and tracking of co-location state, which is not implemented yet.

Signed-off-by: Tomasz Grabiec <tgrabiec@scylladb.com>
2025-10-29 23:32:59 +01:00
Tomasz Grabiec
35166809cb locator: Move rack_list to topology.hh
So that we can use it in locator/tablets.hh and avoid circular dependency
between that header and abstract_replication_strategy.hh
2025-10-29 23:32:58 +01:00
Pavel Emelyanov
92462e502f ec2_snitch: Fix indentation after previous patch
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2025-10-28 19:31:08 +03:00
Pavel Emelyanov
7640ade04d ec2_snitch: Coroutinize the aws_api_call_once()
The method connects a socket, grabs in/out streams from it then writes
HTTP request and reads+parses the response. For that it uses class
variables for socket and streams, but there's no real need for that --
all three actually exists throughput the method "lifetime".

To fix it, coroutinizes the method. The same could be achieved my moving
the connected socket and streams into do_with() context, but coroutine
is better than that.

(indentation is left broken)

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2025-10-28 19:29:25 +03:00
Ferenc Szili
10f07fb95a load_balancer: load_stats reconcile after tablet migration and table resize
This change adds the ability to move tablets sizes in load_stats after a
tablet migration or table resize (split/merge). This is needed because
the size based load balancer needs to have tablet size data which is as
accurate as possible, in order to issue migrations which improve
load balance.
2025-10-28 12:12:09 +01:00
Aleksandra Martyniuk
910cd0918b locator: use get_primary_replica for get_primary_endpoints
Currently, tablet_sstable_streamer::get_primary_endpoints is out of
sync with tablet_map::get_primary_replica. The get_primary_replica
optimizes the choice of the replica so that the work is fairly
distributes among nodes. Meanwhile, get_primary_endpoints always
chooses the first replica.

Use get_primary_replica for get_primary_endpoints.

Fixes: https://github.com/scylladb/scylladb/issues/21883.

Closes scylladb/scylladb#26385
2025-10-28 09:56:08 +02:00
Patryk Jędrzejczak
e1c3f666c9 Merge 'vnode cleanup: add missing barriers and fix race conditions' from Petr Gusev
Problems addressed by this PR

* Missing barrier before cleanup: If a node was bootstrapped before cleanup, some request coordinators could still be in `write_both_read_new` and send stale requests to replicas being cleaned up.
* Sessions not drained before cleanup: We lacked protection against stale streaming or repair operations.
* `sstable_vnodes_cleanup_fiber()` calling `flush_all_tables()` under group0 lock: This caused SCT test failures (see [this comment](https://github.com/scylladb/scylladb/issues/25333#issuecomment-3298859046) for details).
* Issues with `storage_proxy::start_write()` used by `sstable_vnodes_cleanup_fiber`:
  * The result of `start_write()` was not held during `abstract_write_response_handler::apply_locally`, so coordinator-local writes were not properly awaited.
  * Synchronization was racy — `start_write()` was not atomic with the fence check, allowing stale writes to sneak in if `fence_version` changed in between.
  * It waited for all writes, including local tables and tablet-based tables, which is redundant because `sstable_vnodes_cleanup_fiber` does not apply to them.
  * It also waited for writes with versions greater than the current `fence_version`, which is unnecessary.

Fixes scylladb/scylladb#26150

backport: this PR fixes several issues with the vnodes cleanup procedure, but it doesn't seem they are critical enough to deserve backporting

Closes scylladb/scylladb#26315

* https://github.com/scylladb/scylladb:
  test_automatic_cleanup: add test_cleanup_waits_for_stale_writes
  test_fencing: fix due to new version increment
  test_automatic_cleanup: clean it up
  storage_proxy: wait for closing sessions in sstable cleanup fiber
  storage_proxy: rename await_pending_writes -> await_stale_pending_writes
  storage_proxy: use run_fenceable_write
  storage_proxy: abstract_write_response_handler: apply_locally: extract post fence check
  storage_proxy: introduce run_fenceable_write
  storage_proxy: move update_fence_version from shared_token_metadata
  storage_proxy: fix start_write() operation scope in apply_locally
  storage_proxy: move post fence check into handle_write
  storage_proxy: move fencing into mutate_counter_on_leader_and_replicate
  storage_proxy::handle_read: add fence check before get_schema
  storage_service: rebrand cleanup_fiber to vnodes_cleanup_fiber
  sstable_cleanup_fiber: use coroutine::parallel_for_each
  storage_service: sstable_cleanup_fiber: move flush_all_tables out of the group0 lock
  topology_coordinator: barrier before cleanup
  topology_coordinator: small start_cleanup refactoring
  global_token_metadata_barrier: add fenced flag
2025-10-27 12:35:13 +01:00