Commit Graph

59 Commits

Author SHA1 Message Date
Michael Litvak
399260a6c0 test: mv: fix flaky wait for commitlog sync
Previously the test test_interrupt_view_build_shard_registration stopped
the node ungracefully and used commitlog periodic mode to persist the
view build progress in a not very reliable way.

It can happen that due to timing issues, the view build progress is not
persisted, or some of it is persisted in a different ordering than
expected.

To make the test more reliable we change it to stop the node gracefully,
so the commitlog is persisted in a graceful and consistent way, without
using the periodic mode delay. We need to also change the injection for
the shutdown to not get stuck.

Fixes SCYLLADB-1005

Closes scylladb/scylladb#29008
2026-03-19 10:41:21 +01:00
Piotr Dulikowski
a2669e9983 test: test_mv_merge_allowed: add mistakenly omitted awaits
The test test_mv_merge_allowed asserts in two places that the tablet
count is 2. It does so by calling an async function but, mistakenly, the
returned coroutine was not awaited. The coroutine is, apparently, truthy
so the assertions always passed.

Fix the test to properly await the coroutines in the assertions.

Fixes: SCYLLADB-905

Closes scylladb/scylladb#28875
2026-03-05 11:29:23 +01:00
Michael Litvak
8c4bc33e51 test: remove test_view_building_with_tablet_move
remove the test since it's not relevant anymore, it's not testing what
it's supposed to test and it's unstable.

the purpose of the test was to reproduce an issue in the legacy view
builder where a view starts to build at token T2 and then all tokens
[T1, end) with T1<T2 migrate to another node while it's still building,
exposing an issue when the view builder wraparounds the token ring.

this is not relevant anymore because now view building with tablets is
done via the view building coordinator for tablets, and all views start
to build from the first token with no wraparound.

besides, the test is unstable due to relying too much on specific
timing, which was useful for investigating and fixing the original issue
but not anymore.

Fixes SCYLLADB-842

Closes scylladb/scylladb#28842
2026-03-02 07:42:08 +01:00
Alex
5557770b59 test_mv_build_during_shutdown started two async CREATE MATERIALIZED VIEW operations and never awaited them (asyncio.gather(...) without await).
This pr adds await for each one of the tasks to wait for the MV schema to be added successfully
and then to start the server shutdown
With this change we dont need will not get the shutdown races.

Closes scylladb/scylladb#28774
2026-02-24 17:25:05 +01:00
Botond Dénes
b637e17b19 db/config: don't use RBNO for scaling
Remove bootstrap and decomission from allowed_repair_based_node_ops.
Using RBNO over streaming for these operations has no benefits, as they
are not exposed to the out-of-date replica problem that replace,
removenode and rebuild are.
On top of that, RBNO is known to have problems with empty user tables.
Using streaming for boostrap and decomission is safe and faster
than RBNO in all condition, especially when the table is small.

One test needs adjustment as it relies on RBNO being used for all node
ops.

Fixes: SCYLLADB-105

Closes scylladb/scylladb#28080
2026-02-19 09:51:09 +01:00
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
Andrei Chekun
cc5ac75d73 test.py: remove deprecated skip_mode decorator
Finishing the deprecation of the skip_mode function in favor of
pytest.mark.skip_mode. This PR is only cleaning and migrating leftover tests
that are still used and old way of skip_mode.

Closes scylladb/scylladb#28299
2026-01-25 18:17:27 +02:00
Tomasz Grabiec
d3ee82ea51 topology_coordinator, storage_service: Validate node removal/decommission at request submission time
After parallel tablet draining, the validation at the time request
starts executing is too late, tablets will be already drained.

This trips tests which expect validation failure, but get tablet
draining failure instead.

Also, in case of decommission, it's a waste to go through draining
only to discover that the operation has to be rolled back due to
validation.

So avoid submitting a request altogether if it's invalid.
The validation at request execution start remains, for extra sefety.

validate_removing_node() was extracted out of topology_coordinator,
so that it can be called by storage_service on non-coordinator.

Some tests need adjusting for the fact that after failed removenode
the node may still not be marked as excluded, so we need to explicitly
exclude it or add to the list of ignored nodes in the next removenode
operation.
2026-01-18 15:36:04 +01:00
Tomasz Grabiec
5e6935f276 test: Use ManagerClient.{disable,enable}_tablet_balancing() 2026-01-13 00:38:00 +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
Michael Litvak
8f15c7a874 db/view/view_update_generator: move discover_staging_sstables to start
Call discover_staging_sstables in view_update_generator::start() instead
of in the constructor, because the constructor is called during
initialization before sstables are loaded.

The initialization order was changed in 5d1f74b86a and caused this
regression. It means the view update generator won't discover staging
sstables on startup and view updates won't be generated for them. It
also causes issues in sstable cleanup.

view_update_generator::start() is called in a later stage of the
initialization, after sstable loading, so do the discovery of staging
sstables there.

Fixes scylladb/scylladb#27956

Closes scylladb/scylladb#27970
2026-01-08 21:55:19 +02:00
Andrei Chekun
c950c2e582 test.py: convert skip_mode function to pytest.mark
Function skip_mode works only on function and only in cluster test. This if OK
when we need to skip one test, but it's not possible to use it with pytestmark
to automatically mark all tests in the file. The goal of this PR is to migrate

skip_mode to be dynamic pytest.mark that can be used as ordinary mark.

Closes scylladb/scylladb#27853

[avi: apply to test/cluster/test_tablets.py::test_table_creation_wakes_up_balancer]
2026-01-08 21:55:16 +02:00
Michael Litvak
75b5285cdf cql3: don't apply RF-rack restrictions on vector indexes
When creating an index we validate that the keyspace is RF-rack-valid
and print a warning that the keyspace must remain RF-rack-valid.

This should apply only to indexes that are based on materialized views
for which there are consistency concerns when the keyspace is not
RF-rack-valid.

vector indexes are not based on materialized views, hence these
restrictions should not apply to them.
2025-12-22 09:21:07 +01:00
Michael Litvak
06343b58a2 cql3: add warning when creating mv/index with tablets about rf-rack
Creating a MV or index in a tablets-based keyspace now forces additional
restrictions on the keyspace. The keyspace must be RF-rack-valid and it
must remain RF-rack-valid while the view exists.

Add a CQL warning about these restrictions.
2025-12-22 09:21:06 +01:00
Michael Litvak
9940dcefa7 test: test topology restrictions for views with tablets
Add tests that verify the restrictions on topology operations when there
are keyspaces with tablets and materialized views.

For such keyspaces, RF=Racks must be enforced while they have
materialized views, therefore adding a node in a new rack or removing a
node that would eliminate a rack should be rejected.
2025-12-22 09:14:30 +01:00
Michael Litvak
8df61f6d99 view: change validate_view_keyspace to allow MVs if RF=Racks
The function validate_view_keyspace checks if a keyspace is eligible for
having materialized views, and it is used for validation when creating a
MV or a MV-based index.

Previously, it was required that the rf_rack_valid_keyspaces option is
set in order for tablets-based keyspaces to be considered eligible, and
the RF-rack condition was enforced when the option is set.

Instead of this, we change the validation to allow MVs in a keyspace if
the RF-rack condition is satisfied for the keyspace - regardless of the
config option.

We remove the config validation for views on startup that validates the
option `rf_rack_valid_keyspaces` is set if there are any views with
tablets, since this is not required anymore.

We can do this without worrying about upgrades because this change will
be effective from 2025.4 where MVs with tablets are first out of
experimental phase.

We update the test for MV and index restrictions in tablets keyspaces
according to the new requirements.

* Create MV/index: previously the test checked that it's allowed only if
  the config option `rf_rack_valid_keyspaces` is set. This is changed
  now so it's always allowed to create MV/index if the keyspace is
  RF-rack-valid. Update the test to verify that we can create MV/index
  when the keyspace is RF-rack-valid, even if the rf_rack option is not
  set, and verify that it fails when the keyspace is RF-rack-invalid.
* Alter: Add a new test to verify that while a keyspace has views, it
  can't be altered to become RF-rack-invalid.
2025-12-22 09:14:29 +01:00
Dawid Mędrek
58dc414912 test/cluster/mv: Rewrite test_view_building_scheduling_group
We rewrite the test to avoid flakiness. Instead of looking at the
metrics, we make a trade-off and start depending on a less reliable
mechanism -- logs. We grep all relevant messages printed by Scylla
in TRACE mode and make sure that they were all printed from a context
using the streaming scheduling group.

Although it's a "less proper" way of testing, it should be much more
dependable and avoid flakiness.

Fixes scylladb/scylladb#25957

Closes scylladb/scylladb#26656
2025-12-08 14:24:25 +02:00
Aleksandra Martyniuk
76174d1f7a cql3: reject ALTER KEYSPACE if rf of datacenter with tablets is omitted
In ALTER KEYSPACE, when a datacenter name is omitted, its replication
factor is implicitly set to zero with vnodes, while with tablets,
it remains unchanged.

ALTER KEYSPACE should behave the same way for tablets as it does
for vnodes. However, this can be dangerous as we may mistakenly
drop the whole datacenter.

Reject ALTER KEYSPACE if it changes replication factor, but omits
a datacenter that currently contains tablet replicas.

Fixes: https://github.com/scylladb/scylladb/issues/25549.

Closes scylladb/scylladb#25731
2025-11-24 06:36:51 +02:00
Botond Dénes
2ca66133a4 Revert "db/config: don't use RBNO for scaling"
This reverts commit 43738298be.

This commit causes instability in dtests. Several non-gating dtests
started failing, as well as some gating ones, see #27047.

Closes scylladb/scylladb#27067

Fixes #27047
2025-11-18 08:17:17 +02:00
Piotr Dulikowski
2ccc94c496 Merge 'topology_coordinator: include joining node in barrier' from Michael Litvak
Previously, only nodes in the 'normal' state and decommissioning nodes
were included in the set of nodes participating in barrier and
barrier_and_drain commands. Joining nodes are not included because they
don't coordinate requests, given their cql port is closed.

However, joining nodes may receive mutations from other nodes, for which
they may generate and coordinate materialized view updates. If their
group0 state is not synchronized it could cause lost view updates.
For example:

1. On the topology coordinator, the join completes and the joining node
   becomes normal, but the joining node's state lags behind. Since it's
   not synchronized by the barrier, it could be in an old state such as
   `write_both_read_old`.
2. A normal node coordinates a write and sends it to the new node as the
   new replica.
3. The new node applies the base mutation but doesn't generate a view
   update for it, because it calculates the base-view pairing according
   to its own state and replication map, and determines that it doesn't
   participate in the base-view pairing.

Therefore, since the joining node participates as a coordinator for view
updates, it should be included in these barriers as well. This ensures
that before the join completes, the joining node's state is
`write_both_read_new`, where it does generate view updates.

Fixes https://github.com/scylladb/scylladb/issues/26976

backport to previous versions since it fixes a bug in MV with vnodes

Closes scylladb/scylladb#27008

* github.com:scylladb/scylladb:
  test: add mv write during node join test
  topology_coordinator: include joining node in barrier
2025-11-14 12:41:16 +01:00
Botond Dénes
43738298be db/config: don't use RBNO for scaling
Remove bootstrap and decomission from allowed_repair_based_node_ops.
Using RBNO over streaming for these operations has no benefits, as they
are not exposed to the out-of-date replica problem that replace,
removenode and rebuild are.
On top of that, RBNO is known to have problems with empty user tables.
Using streaming for boostrap and decomission is safe and faster
than RBNO in all condition, especially when the table is small.

One test needs adjustment as it relies on RBNO being used for all node
ops.

Fixes: #24664

Closes scylladb/scylladb#26330
2025-11-14 13:03:50 +03:00
Dawid Mędrek
393f1ca6e6 tet/cluster/mv: Clean up test_backoff_when_node_fails_task_rpc
After the changes in the test, we clean up its syntax. It boils
down to very simple modifications.
2025-11-13 17:57:33 +01:00
Dawid Mędrek
acd9120181 db/view/view_building_coordinator: Rate limit logging failed RPC
The view building coordinator sends tasks in form of RPC messages
to other nodes in the cluster. If processing that RPC fails, the
coordinator logs the error.

However, since tasks are per replica (so per shard), it may happen
that we end up with a large number of similar messages, e.g. if the
target node has died, because every shard will fail to process its
RPC message. It might become even worse in the case of a network
partition.

To mitigate that, we rate limit the logging by 1 seconds.

We extend the test `test_backoff_when_node_fails_task_rpc` so that
it allows the view building coordinator to have multiple tablet
replica targets. If not for rate limiting the warning messages,
we should start getting more of them, potentially leading to
a test failure.
2025-11-13 17:57:23 +01:00
Dawid Mędrek
4a5b1ab40a db/view: Add backoff when RPC fails
The view building coordinator manages the process of view building
by sending RPC requests to all nodes in the cluster, instructing them
what to do. If processing that message fails, the coordinator decides
if it wants to retry it or (temporarily) abandon the work.

An example of the latter scenario could be if one of the target nodes
dies and any attempts to communicate with it would fail.

Unfortunately, the current approach to it is not perfect and may result
in a storm of warnings, effectively clogging the logs. As an example,
take a look at scylladb/scylladb#26686: the gossiper failed to mark
one of the dead nodes as DOWN fast enough, and it resulted in a warning storm.

To prevent situations like that, we implement a form of backoff.
If processing an RPC message fails, we postpone finishing the task for
a second. That should reduce the number of messages in the logs and avoid
retries that are likely to fail as well.

We provide a reproducer test: it fails before this commit and succeeds
with it.

Fixes scylladb/scylladb#26686
2025-11-13 17:55:41 +01:00
Michael Litvak
b925e047be test: add mv write during node join test
Add a test that reproduces the issue scylladb/scylladb#26976.

The test adds a new node with delayed group0 apply, and does writes with
MV updates right after the join completes on the coordinator and while
the joining node's state is behind.

The test fails before fixing the issue and passes after.
2025-11-13 12:24:32 +01:00
Piotr Szymaniak
63897370cb alternator: Fix tag name to request vnodes
The tag was lately renamed from `experimental:initial_tablets` to
`system::initial_tablets`. This commit fixes both the tests as well as
the exceptions sent to the user instructing how to create table with
vnodes.
2025-11-09 12:52:29 +02:00
Wojciech Mitros
0a22ac3c9e mv: don't mark the view as built if the reader produced no partitions
When we build a materialized view we read the entire base table from start to
end to generate all required view udpates. If a view is created while another view
is being built on the same base table, this is optimized - we start generating
view udpates for the new view from the base table rows that we're currently
reading, and we read the missed initial range again after the previous view
finishes building.
The view building progress is only updated after generating view updates for
some read partitions. However, there are scenarios where we'll generate no
view updates for the entire read range. If this was not handled we could
end up in an infinite view building loop like we did in https://github.com/scylladb/scylladb/issues/17293
To handle this, we mark the view as built if the reader generated no partitions.
However, this is not always the correct conclusion. Another scenario where
the reader won't encounter any partitions is when view building is interrupted,
and then we perform a reshard. In this scenario, we set the reader for all
shards to the last unbuilt token for an existing partition before the reshard.
However, this partition may not exist on a shard after reshard, and if there
are also no partitions with higher tokens, the reader will generate no partitions
even though it hasn't finished view building.
Additionally, we already have a check that prevents infinite view building loops
without taking the partitions generated by the reader into account. At the end
of stream, before looping back to the start, we advance current_key to the end
of the built range and check for built views in that range. This handles the case
where the entire range is empty - the conditions for a built view are:
1. the "next_token" is no greater than "first_token" (the view building process
looped back, so we've built all tokens above "first_token")
2. the "current_token" is no less than "first_token" (after looping back, we've
built all tokens below "first_token")

If the range is empty, we'll pass these conditions on an empty range after advancing
"current_key" to the end because:
1. after looping back, "next_token" will be set to `dht::minimum_token`
2. "current_key" will be set to `dht::ring_position::max()`

In this patch we remove the check for partitions generated by the reader. This fixes
the issue with resharding and it does not resurrect the issue with infinite view building
that the check was introduced for.

Fixes https://github.com/scylladb/scylladb/issues/26523

Closes scylladb/scylladb#26635
2025-11-05 17:02:32 +02:00
Tomasz Grabiec
5bf7112fe6 test: cluster: mv: Do not move tablets across racks
It's illegal with rf-rack-valid keyspaces.
2025-10-29 23:32:57 +01:00
Piotr Dulikowski
a8d92f2abd test: mv: add a test for tablet merge
The test test_mv_tablets_replace verifies that merging tablets of both a
view and its base table is allowed if rf-rack-valid-keyspaces option is
enabled (and it is enabled by default in the test suite).
2025-10-16 14:07:37 +02:00
Dawid Mędrek
3aa07d7dfe test/cluster/mv: Provide reason why test is skipped
We point to the issue explaining why the test was disabled
and what can be done about it.

Closes scylladb/scylladb#26541
2025-10-15 09:22:39 +02:00
Piotr Dulikowski
e7907b173a Merge 'db/view: Require rf_rack_valid_keyspaces when creating materialized view' from Dawid Mędrek
Materialized views are currently in the experimental phase and using them
in tablet-based keyspaces requires starting Scylla with an experimental feature,
`views-with-tablets`. Any attempts to create a materialized view or secondary
index when it's not enabled will fail with an appropriate error.

After considerable effort, we're drawing close to bringing views out of the
experimental phase, and the experimental feature will no longer be needed.
However, materialized views in tablet-based keyspaces will still be restricted,
and creating them will only be possible after enabling the configuration option
`rf_rack_valid_keyspaces`. That's what we do in this PR.

In this patch, we adjust existing tests in the tree to work with the new
restriction. That shouldn't have been necessary because we've already seemingly
adjusted all of them to work with the configuration option, but some tests hid
well. We fix that mistake now.

After that, we introduce the new restriction. What's more, when starting Scylla,
we verify that there is no materialized view that would violate the contract.
If there are some that do, we list them, notify the user, and refuse to start.

High-level implementation strategy:

1. Name the restrictions in form of a function.
2. Adjust existing tests.
3. Restrict materialized views by both the experimental feature
   and the configuration option. Add validation test.
4. Drop the requirement for the experimental feature. Adjust the added test
   and add a new one.
5. Update the user documentation.

Fixes scylladb/scylladb#23030

Backport: 2025.4, as we are aiming to support materialized views for tablets from that version.

Closes scylladb/scylladb#25802

* github.com:scylladb/scylladb:
  view: Stop requiring experimental feature
  db/view: Verify valid configuration for tablet-based views
  db/view: Require rf_rack_valid_keyspaces when creating view
  test/cluster/random_failures: Skip creating secondary indexes
  test/cluster/mv: Mark test_mv_rf_change as skipped
  test/cluster: Adjust MV tests to RF-rack-validity
  test/boost/schema_loader_test.cc: Explicitly enable rf_rack_valid_keyspaces
  db/view: Name requirement for views with tablets
2025-10-06 12:46:46 +02:00
Dawid Mędrek
b409e85c20 view: Stop requiring experimental feature
We modify the requirements for using materialized views in tablet-based
keyspaces. Before, it was necessary to enable the configuration option
`rf_rack_valid_keyspaces`, having the cluster feature `VIEWS_WITH_TABLETS`
enabled, and using the experimental feature `views-with-tablets`.
We drop the last requirement.

We adjust code to that change and provide a new validation test.
We also update the user documentation to reflect the changes.

Fixes scylladb/scylladb#23030
2025-10-01 09:01:53 +02:00
Dawid Mędrek
00222070cd db/view: Require rf_rack_valid_keyspaces when creating view
We extend the requirements for being able to create materialized views
and secondary indexes in tablet-based keyspaces. It's now necessary to
enable the configuration option `rf_rack_valid_keyspaces`. This is
a stepping stone towards bringing materialized views and secondary
indexes with tablets out of the experimental phase.

We add a validation test to verify the changes.

Refs scylladb/scylladb#23030
2025-10-01 09:01:50 +02:00
Dawid Mędrek
6322b5996d test/cluster/mv: Mark test_mv_rf_change as skipped
The test will not work with `rf_rack_valid_keyspaces`. Since the option
is going to become a requirement for using views with tablets, the test
will need to be rewritten to take that into consideration. Since that
adjustment doesn't seem trivial, we mark the test as skipped for the
time being.
2025-10-01 09:01:29 +02:00
Dawid Mędrek
994f09530f test/cluster: Adjust MV tests to RF-rack-validity
Some of the new tests covering materialized views explicitly disabled
the configuration option `rf_rack_valid_keyspaces`. It's going to become
a new requirement for views with tablets, so we adjust those tests and
enable the option. There is one exception, the test:

`cluster/mv/test_mv_topology_change.py::test_mv_rf_change`

We handle it separately in the following commit.
2025-09-30 20:01:25 +02:00
Michael Litvak
d94c1f6674 test: mv: test view update during topology operations
add new test cases checking view consistency when writing to a table
with MV and generating view updates while data is migrated.

one case has tablet migrations while writing to the table. The other
case does the equivalent for vnode keyspaces - it adds a new node.

The tests reproduce issue scylladb/scylladb#24292
2025-09-29 13:44:04 +02:00
Wojciech Mitros
d9b8278178 mv: handle mismatched base/view replica count caused by RF change
During an ALTER KEYSPACE statement execution where a table with a view
is present, we need to perform tablet migrations for both tables.
These migrations are not synchronized, so at some point the base may
have a different number of non-pending replicas than the view. Because
of that, we can't pair them correctly. If there is more non-pending
base replicas than view replicas, we don't need to do anything because
the view replica that didn't finish migrating is a pending replica
and will get view updates from all base replicas. But if there is more
non-pending view replicas than base replicas, we may currently lose
view updates to the new view replica.

This patch adds a workaround for this scenario. If after one migration
we have too more non-pending view replicas than base replicas, we add
it to the pending replica list so that it gets an update anyway.

This patch will also take effect if the base and view replica counts
differ due to some other bug. To track that, a new metric is added
to count such occurrences.

This patch also includes a test for this exact scenario, which is enforced by an injection.

Fixes https://github.com/scylladb/scylladb/issues/21492
2025-09-22 12:50:16 +02:00
Michael Litvak
3dffb8e0dc test: mv: add a test for view build interrupt during registration
Add a new test that reproduces issue #22989. The test starts view
building and interrupts it by restarting the node while some shards
registered their status and some didn't.
2025-09-21 10:39:30 +02:00
Wojciech Mitros
f17beba834 load_balancer: include dead nodes when calculating rack load
Load balancer aims to preserve a balance in rack loads when generating
tablet migrations. However, this balance might get broken when dead nodes
are present. Currently, these nodes aren't include in rack load calculations,
even if they own tablet replicas. As a result, load balancer treats racks
with dead nodes as racks with a lower load, so I generates migrations to these
racks.
This is incorrect, because a dead node might come back alive, which would result
in having multiple tablet replicas on the same rack. It's also inefficient
even if we know that the node won't come back - when it's being replaced or removed.
In that case we know we are going to rebuild the lost tablet replicas
so migrating tablets to this rack just doubles the work. Allowing such migrations
to happen would also require adjustments in the materialized view pairing code
because we'd temporarily allow having multiple tablet replicas on the same rack.
So in this patch we include dead nodes when calculating rack loads in the load
balancer. The dead nodes still aren't treated as potential migration sources or
destinations.
We also add a test which verifies that no migrations are performed by doing a node
replace with a mv workload in parallel. Before the patch, we'd get pairing errors
and after the patch, no pairing errors are detected.

Fixes https://github.com/scylladb/scylladb/issues/24485

Closes scylladb/scylladb#26028
2025-09-17 20:49:18 +02:00
Michał Jadwiszczak
cf138da853 test: adjust existing tests
- Disable tablets in `test_migration_on_existing_raft_topology`.
Because views on tablets are experimental now, we can safely
assume that view building coordinator will start with view build status
on raft.
- Add error injection to pause view building on worker.
Used to pause view building process, there is analogous error injection
in view_builder.
- Do a read barrier in `test_view_in_system_tables`
Increases test stability by making sure that the node sees up-to-date
group0 state and `system.built_views` is synced.
- Wait for view is build in some tests
Increases tests stability by making sure that the view is built.
- Remove xfail marker from `test_tablet_streaming_with_unbuilt_view`
This series fix https://github.com/scylladb/scylladb/issues/21564
and this test should work now.
2025-08-27 10:23:04 +02:00
Wojciech Mitros
2ece08ba43 test: run mv tests depending on metrics on a standalone instance
The test_base_partition_deletion_with_metrics test case (and the batch
variant) uses the metric of view updates done during its runtime to check
if we didn't perform too many of them. The test runs in the cqlpy suite,
which  runs all test cases sequentially on one Scylla instance. Because
of this, if another test case starts a process which generates view
updates and doesn't wait for it to finish before it exists, we may
observe too many view updates in test_base_partition_deletion_with_metrics
and fail the test.
In all test cases we make sure that all tables that were created
during the test are dropped at the end. However, that doesn't
stop the view building process immediately, so the issue can happen
even if we drop the view. I confirmed it by adding a test just before
test_base_partition_deletion_with_metrics which builds a big
materialized view and drops it at the end - the metrics check still failed.

The issue could be caused by any of the existing test cases where we create
a view and don't wait for it to be built. Note that even if we start adding
rows after creating the view, some of them may still be included in the view
building, as the view building process is started asynchronously. In such
a scenario, the view building also doesn't cause any issues with the data in
these tests - writes performed after view creation generate view updates
synchronously when they're local (and we're running a single Scylla server),
the corresponding view udpates generated during view building are redundant.

Because we have many test cases which could be causing this issue, instead
of waiting for the view building to finish in every single one of them, we
move the susceptible test cases to be run on separate Scylla instances, in
the "cluster" suite. There, no other test cases will influence the results.

Fixes https://github.com/scylladb/scylladb/issues/20379

Closes scylladb/scylladb#25209
2025-08-13 15:08:50 +03:00
Michael Litvak
276a09ac6e test: test_mv_backlog: fix to consider internal writes
The test executes a single write, fetching metrics before and after the
write, and expects the total throttled writes count to be increased
exactly by one.

However, other internal writes (compaction for example) may be executed
during this time and be throttled, causing the metrics to be increased
by more than expected.

To address this, we filter the metrics by the scheduling group label of
the user write, to filter out the compaction writes that run in the
compaction scheduling group.

Fixes scylladb/scylladb#23139
2025-08-10 10:31:02 +02:00
Michael Litvak
5c28cffdb4 test/pylib/rest_client: fix ScyllaMetrics filtering
In the ScyllaMetrics `get` function, when requesting the value for a
specific shard, it is expected to return the sum of all values of
metrics for that shard that match the labels.

However, it would return the value of the first matching line it finds
instead of summing all matching lines.

For example, if we have two lines for one shard like:
some_metric{scheduling_group_name="compaction",shard="0"} 1
some_metric{scheduling_group_name="sl:default",shard="0"} 2

The result of this call would be 1 instead of 3:
get('some_metric', shard="0")

We fix this to sum all matching lines.

The filtering of lines by labels is fixed to allow specifying only some
of the labels. Previously, for the line to match the filter, either the
filter needs to be empty, or all the labels in the metric line had to be
specified in the filter parameter and match its value, which is
unexpected, and breaks when more labels are added.

We also simplify the function signature and the implementation - instead
of having the shard as a separate parameter, it can be specified as a
label, like any other label.
2025-08-10 10:16:00 +02:00
Artsiom Mishuta
4b975668f6 tiering (test.py): introduce tiering labels
introduce tiering marks
1 “unstable” - For unstable tests that will be will continue runing every night and generate up-to-date statistics with failures without failing the “Main” verification path(scylla-ci, Next)

2 “nightly” - for tests that are quite old, stable, and test functionality that rather not be changed or affected by other features, are partially covered in other tests, verify non-critical functionality, have not found any issues or regressions, too long to run on every PR,  and can be popped out from the CI run.

set 7 long tests(according to statistic in elastic) as nightly(theses 8 tests took 20% of CI run,
about 4 hours without paralelization)
1 test as unstable(as exaple ot marker usage)

Closes scylladb/scylladb#24974
2025-08-04 15:38:16 +03:00
Taras Veretilnyk
1d6808aec4 topology_coordinator: Make tablet_load_stats_refresh_interval configurable
This commits introduces an config option 'tablet_load_stats_refresh_interval_in_seconds'
that allows overriding the default value without using error injection.

Fixes scylladb/scylladb#24641

Closes scylladb/scylladb#24746
2025-07-31 14:31:55 +03:00
Michael Litvak
e01aae7871 test/pylib/tablets: common get_tablet_count api
Introduce a common get_tablet_count test api instead of it being
duplicated in few tests, and fix it to read the tablet count from the
base table.
2025-07-01 13:20:19 +03:00
Michael Litvak
e719da3739 test_mv_tablets: use get_tablet_replicas from common tablets api
Replace the duplicated get_tablet_replicas method in test_mv_tablets
with the common method from the tablets api, to reduce code duplication
and use the correct method that reads the tablet replicas from the base
table.
2025-07-01 13:20:19 +03:00
Wojciech Mitros
5074daf1b7 test: actually wait for tablets to distribute across nodes
In test_tablet_mv_replica_pairing_during_replace, after we create
the tables, we want to wait for their tablets to distribute evenly
across nodes and we have a wait_for for that.
But we don't await this wait_for, so it's a no-op. This patch fixes
it by adding the missing await.

Refs scylladb/scylladb#23982
Refs scylladb/scylladb#23997

Closes scylladb/scylladb#24250
2025-05-27 15:12:25 +02:00
Wojciech Mitros
bceb64fb5a test_mv_tablets_replace: wait for tablet replicas to balance before working on them
In the test test_tablet_mv_replica_pairing_during_replace we stop 2 out of 4 servers while using RF=2.
Even though in the test we use exactly 4 tablets (1 for each replica of a base table and view), intially,
the tablets may not be split evenly between all nodes. Because of this, even when we chose a server that
hosts the view and a different server that hosts the base table, we sometimes stoped all replicas of the
base or the view table because the node with the base table replica may also be a view replica.

After some time, the tablets should be distributed across all nodes. When that happens, there will be
no common nodes with a base and view replica, so the test scenario will continue as planned.

In this patch, we add this waiting period after creating the base and view, and continue the test only
when all 4 tablets are on distinct nodes.

Fixes https://github.com/scylladb/scylladb/issues/23982
Fixes https://github.com/scylladb/scylladb/issues/23997

Closes scylladb/scylladb#24111
2025-05-12 16:17:48 +02:00
Nadav Har'El
262530f27c Merge 'mv: make base_info in view schemas immutable' from Wojciech Mitros
Currently, the base_info may or may not be set in view schemas.
Even when it's set, it may be modified. This necessitates extra
checks when handling view schemas, as we'll as potentially causing
errors when we forget to set it at some point.

Instead, we want to make the base info an immutable member of view
schemas (inside view_info). To achieve this, in this series we remove
all base_info members that can change due to a base schema update,
and we calculate the remaining values during view update generation,
using the most up-to-date base schema version.

To calculate the values that depend on the base schema version, we
need to iterate over the view primary key and find the corresponding
columns, which adds extra overhead for each batch of view updates.
However, this overhead should be relatively small, as when creating
a view update, we need to prepare each of its columns anyway. And
if we need to read the old value of the base row, the relative
overhead is even lower.

After this change, the base info in view schemas stays the same
for all base schema updates, so we'll no longer get issues with
base_info being incompatible with a base schema version. Additionally,
it's a step towards making the schema objects immutable, which
we sometimes incorrectly assumed in the past (they're still not
completely immutable yet, as some other fields in view_info other
than base_info are initialized lazily and may depend on the base
schema version).

Fixes https://github.com/scylladb/scylladb/issues/9059
Fixes https://github.com/scylladb/scylladb/issues/21292
Fixes https://github.com/scylladb/scylladb/issues/22194
Fixes https://github.com/scylladb/scylladb/issues/22410

Closes scylladb/scylladb#23337

* github.com:scylladb/scylladb:
  test: remove flakiness from test_schema_is_recovered_after_dying
  mv: add a test for dropping an index while it's building
  base_info: remove the lw_shared_ptr variant
  view_info: don't re-set base_info after construction
  base_info: remove base_info snapshot semantics
  base_info: remove base schema from the base_info
  schema_registry: store base info instead of base schema for view entries
  base_info: make members non-const
  view_info: move the base info to a separate header
  view_info: move computation of view pk columns not in base pk to view_updates
  view_info: move base-dependent variables into base_info
  view_info: set base info on construction
2025-04-27 19:12:12 +03:00