Commit Graph

284 Commits

Author SHA1 Message Date
Botond Dénes
122b7847e5 Merge 'index: Accept view properties in CREATE INDEX' from Dawid Mędrek
Problem
-------
Secondary indexes are implemented via materialized views under the
hood. The way an index behaves is determined by the configuration
of the view. Currently, it can be modified by performing the CQL
statement `ALTER MATERIALIZED VIEW` on it. However, that raises some
concerns.

Consider, for instance, the following scenario:

1. The user creates a secondary index on a table.
2. In parallel, the user performs writes to the base table.
3. The user modifies the underlying materialized view, e.g. by setting
   the `synchronous_updates` to `true` [1].

Some of the writes that happened before step 3 used the default value
of the property (which is `false`). That had an actual consequence
on what happened later on: the view updates were performed
asynchronously. Only after step 3 had finished did it change.

Unfortunately, as of now, there is no way to avoid a situation like
that. Whenever the user wants to configure a secondary index they're
creating, they need to do it in another schema change. Since it's
not always possible to control how the database is manipulated in
the meantime, it leads to problems like the one described.

That's not all, though. The fact that it's not possible to configure
secondary indexes is inconsistent with other schema entities. When
it comes to tables or materialized views, the user always have a means
to set some or even all of the properties during their creation.

Solution
--------
The solution to this problem is extending the `CREATE INDEX` CQL
statement by view properties. The syntax is of form:

```
> CREATE INDEX <index name>
> .. ON <keyspace>.<table> (<columns>)
> .. WITH <properties>
```

where `<properties>` corresponds to both index-specific and view
properties [2, 3]. View properties can only be used with indexes
implemented with materialized views; for example, it will be impossible
to create a vector index when specifying any view property (see
examples below).

When a view property is provided, it will be applied when creating the
underlying materialized view. The behavior should be similar to how
other CQL statements responsible for creating schema entities work.

High-level implementation strategy
----------------------------------
1. Make auxiliary changes.
2. Introduce data structures representing the new set of index
   properties: both index-specific and those corresponding to the
   underlying view.
3. Extend `CREATE INDEX` to accept view properties.
4. Extend `DESCRIBE INDEX` and other `DESCRIBE` statements to include
   view properties in their output.

User documentation is also updated at the steps to reflect the
corresponding changes.

Implementation considerations
-----------------------------
There are a number of schema properties that are now obsolete. They're
accepted by other CQL statements, but they have no effect. They
include:

* `index_interval`
* `replicate_on_write`
* `populate_io_cache_on_flush`
* `read_repair_chance`
* `dclocal_read_repair_chance`

If the user tries to create a secondary index specifying any of those
keywords, the statement will fail with an appropriate error (see
examples below).

Unlike materialized views, we forbid specifying the clustering order
when creating a secondary index [4]. This limitation may be lifted
later on, but it's a detail that may or may not prove troublesome. It's
better to postpone covering it to when we have a better perspective on
the consequences it would bring.

Examples
--------
Good examples
```
> CREATE INDEX idx ON ks.t (v);
> CREATE INDEX idx ON ks.t (v) WITH comment = 'ok view property';
> CREATE INDEX idx ON ks.t (v)
  .. WITH comment = 'multiple view properties are ok'
  .. AND synchronous_updates = true;
> CREATE INDEX idx ON ks.t (v)
  .. WITH comment = 'default value ok'
  .. AND synchronous_updates = false;
```

Bad examples
```
> CREATE INDEX idx ON ks.t (v) WITH replicate_on_write = true;

SyntaxException: Unknown property 'replicate_on_write'

> CREATE INDEX idx ON ks.t (v)
  .. WITH OPTIONS = {'option1': 'value1'}
  .. AND comment = 'some text';

InvalidRequest: Error from server: code=2200 [Invalid query]
  message="Cannot specify options for a non-CUSTOM index"

> CREATE CUSTOM INDEX idx ON ks.t (v)
  .. WITH OPTIONS = {'option1': 'value1'}
  .. AND comment = 'some text';

InvalidRequest: Error from server: code=2200 [Invalid query]
  message="CUSTOM index requires specifying the index class"

> CREATE CUSTOM INDEX idx ON ks.t (v)
  .. USING 'vector_index'
  .. WITH OPTIONS = {'option1': 'value1'}
  .. AND comment = 'some text';

InvalidRequest: Error from server: code=2200 [Invalid query]
  message="You cannot use view properties with a vector index"

> CREATE INDEX idx ON ks.t (v) WITH CLUSTERING ORDER BY (v ASC);

InvalidRequest: Error from server: code=2200 [Invalid query]
  message="Indexes do not allow for specifying the clustering order"
```

and so on. For more examples, see the relevant tests.

References:
[1] https://docs.scylladb.com/manual/branch-2025.4/cql/cql-extensions.html#synchronous-materialized-views
[2] https://docs.scylladb.com/manual/branch-2025.4/cql/secondary-indexes.html#create-index
[3] https://docs.scylladb.com/manual/branch-2025.4/cql/mv.html#mv-options
[4] https://docs.scylladb.com/manual/branch-2025.4/cql/dml/select.html#ordering-clause

Fixes scylladb/scylladb#16454

Backport: not needed. This is an enhancement.

Closes scylladb/scylladb#24977

* github.com:scylladb/scylladb:
  cql3: Extend DESC INDEX by view properties
  cql3: Forbid using CLUSTERING ORDER BY when creating index
  cql3: Extend CREATE INDEX by MV properties
  cql3/statements/create_index_statement: Allow for view options
  cql3/statements/create_index_statement: Rename member
  cql3/statements/index_prop_defs: Re-introduce index_prop_defs
  cql3/statements/property_definitions: Add extract_property()
  cql3/statements/index_prop_defs.cc: Add namespace
  cql3/statements/index_prop_defs.hh: Rename type
  cql3/statements/view_prop_defs.cc: Move validation logic into file
  cql3/statements: Introduce view_prop_defs.{hh,cc}
  cql3/statements/create_view_statement.cc: Move validation of ID
  schema/schema.hh: Do not include index_prop_defs.hh
2026-01-14 09:54:27 +02:00
Nadav Har'El
609b283d98 test/cqlpy: add another reproducer for known issue
This patch adds a second reproducer for issue #25839, which is about
scanning a secondary index which returns partial results. The new test
uses count(*) without requesting the row themselves, but still has the
same problem of counting only part of the rows. This is the problem that
a user reported in issue #28026.

Unlike the previous test, this test works correctly on older versions
of Scylla - by using larger data, like on Cassandra - without changing
a configuration variable that did not yet exist. So with this test we
can confirm that this bug is a Scylla 5.2 regression:

  test/cqlpy/run --release 5.1 test_secondary_index.py::test_short_count

passes, while

  test/cqlpy/run --release 5.2 test_secondary_index.py::test_short_count

fails. It also fails on master, so the new test is marked "xfail".

Refs #25839
Refs #28026

Signed-off-by: Nadav Har'El <nyh@scylladb.com>

Closes scylladb/scylladb#28108
2026-01-13 11:15:27 +02:00
Botond Dénes
7b562bb185 Merge 'system.clients: Address SSL refactor review comments' from Piotr Smaron and Copilot
Addresses outstanding review comments from PR #22961 where SSL field
collection was refactored into generic_server::connection base class.
This patch consists of minor cosmetic enhancements for increased
readability, mainly, with some minor fixups explained in specific
commits.

Cosmetic changes, no need to backport.

Closes scylladb/scylladb#27575

* github.com:scylladb/scylladb:
  test_ssl: fix indentation
  generic_server: improve logging broken TLS connection
  test_ssl: improve timeout and readability
  alternator/server: update SSL comment
2026-01-13 11:00:26 +02:00
Nadav Har'El
a1f198d453 test/cqlpy: translate Cassandra's test InsertInvalidateSizedRecordsTest
This is a translation of Cassandra's CQL unit test source file
validation/operations/InsertInvalidateSizedRecordsTest.java into our
cqlpy framework.

This is one of the tests added to Cassandra as part of the vector
search work, but actually has nothing to do with vector search -
it checks what happens when key columns of different types exceeed
their maximum size (64KB).

Unfortunately, each one of the tests added here *fail* on ScyllaDB,
providing more reproducers for two already known issues (which
already had plenty of reproducers...):

Refs  #8627 Cleanly reject updates with indexed values where value > 64k
Refs #12247 Better error reporting for oversized keys during INSERT

One of the tests also fails on Cassandra, due to CASSANDRA-19270.
It is not clear to me how this unit test actually passed on Cassandra,
I can only guess that the Python driver somehow makes the request
differently than what the Java unit tests use to make requests to
Cassandra.

One of the tests in the original Cassandra source file I did not
translate, readingEmptyStringsForDifferentTypes, because it tests
cqlsh, not pure CQL.

Signed-off-by: Nadav Har'El <nyh@scylladb.com>

Closes scylladb/scylladb#27944
2026-01-13 08:59:36 +02:00
Botond Dénes
6bcc18e5c6 erge 'test.py: integrate python tests to be executed with pytest runner' from Andrei Chekun
This will move responsibility for running tests with pytest in the same manner as it was done with boost tests. From this commit, test.py is not responsible anymore for running python tests and relies completely on pytest.
This is another step for unification of test execution.
Convert skip_mode function to `pytest.mark` to be able to use to annotate the whole module instead of each test explicitly.

NOTE: this is a breaking change. From this commit, several directories with tests will require a path to the file to launch the test. Affected directories
test/alternator
test/broadcast_tables
test/cql
test/cqlpy
test/rest_api

Changes only in framework, so no backport.

This PR will increase the amount of the tests by 30 test, due to the fact that how test.py and pytest discover tests. test.py count a file as a test, and when skip used in suite.yaml it will exclude the tests from discovery completely.
While the pytest count test funstion as a test and uses skip_mode mark and will discover the tests, but it will skip them during execution, hence the difference
test.py output before PR:
```bash
> ./test.py --mode=release  rest_api/test_compaction_task rest_api/test_task_manager --list --no-gather-metrics

```
test.py output in this PR:
```bash
> ./test.py --mode=release  test/rest_api/test_compaction_task.py test/rest_api/test_task_manager.py --list

rest_api/test_compaction_task.py::test_global_major_keyspace_compaction_task.release.1
rest_api/test_compaction_task.py::test_major_keyspace_compaction_task.release.1
rest_api/test_compaction_task.py::test_cleanup_keyspace_compaction_task.release.1
rest_api/test_compaction_task.py::test_offstrategy_keyspace_compaction_task.release.1
rest_api/test_compaction_task.py::test_rewrite_sstables_keyspace_compaction_task.release.1
rest_api/test_compaction_task.py::test_reshaping_compaction_task.release.1
rest_api/test_compaction_task.py::test_resharding_compaction_task.release.1
rest_api/test_compaction_task.py::test_regular_compaction_task.release.1
rest_api/test_compaction_task.py::test_compaction_task_abort.release.1
rest_api/test_compaction_task.py::test_major_keyspace_compaction_task_async.release.1
rest_api/test_compaction_task.py::test_cleanup_keyspace_compaction_task_async.release.1
rest_api/test_compaction_task.py::test_offstrategy_keyspace_compaction_task_async.release.1
rest_api/test_compaction_task.py::test_rewrite_sstables_keyspace_compaction_task_async.release.1
rest_api/test_compaction_task.py::test_compaction_progress[major_keyspace_compaction_task_impl_run_fail].release.1
rest_api/test_compaction_task.py::test_compaction_progress[shard_major_keyspace_compaction_task_impl_run_fail].release.1
rest_api/test_compaction_task.py::test_compaction_progress[table_major_keyspace_compaction_task_impl_run_fail].release.1
rest_api/test_task_manager.py::test_task_manager_modules.release.1
rest_api/test_task_manager.py::test_task_manager_tasks.release.1
rest_api/test_task_manager.py::test_task_manager_status_running.release.1
rest_api/test_task_manager.py::test_task_manager_status_done.release.1
rest_api/test_task_manager.py::test_task_manager_status_failed.release.1
rest_api/test_task_manager.py::test_task_manager_not_abortable.release.1
rest_api/test_task_manager.py::test_task_manager_wait.release.1
rest_api/test_task_manager.py::test_task_manager_ttl.release.1
rest_api/test_task_manager.py::test_task_manager_user_ttl.release.1
rest_api/test_task_manager.py::test_task_manager_sequence_number.release.1
rest_api/test_task_manager.py::test_task_manager_recursive_status.release.1
rest_api/test_task_manager.py::test_module_not_exists.release.1
rest_api/test_task_manager.py::test_task_folding.release.1
rest_api/test_task_manager.py::test_abort_on_unregistered_task.release.1
```

Fixes: https://github.com/scylladb/scylladb/issues/27716

Closes scylladb/scylladb#26395

* github.com:scylladb/scylladb:
  test.py: fix test_vector_similarity.py
  docs: add directories excluded from test.py
  test.py: prevent file descriptors leaking
  test.py: capture print inside the test
  test.py: do not print header for collection with test.py
  test.py: remove not supported functionality
  test.py: switch of execution of several test directories by test.py runner
  test.py: integrate python tests to be executed with pytest runner
  test.py: fix test/vector_search_validator to be able to run with pytest
  test.py: prepare base class for migration
  test.py: move environment preparation to one method
  test.py: introduce new environment variable TESTPY_PREPARED_ENVIRONMENT
2026-01-12 14:17:19 +02:00
Michał Hudobski
92c988514c vector_search: allow all where clauses in vector search queries
To prepare for implementation of filtering we skip validation
of where clauses in vector search queries. All queries that would
be blocked by the lack of ALLOW FILTERING now will pass through.

Fixes: VECTOR-410

Closes scylladb/scylladb#27758
2026-01-11 12:56:44 +02:00
Andrei Chekun
1f60208aa0 test.py: fix test_vector_similarity.py
There is a known limitation of the xdist.
Since it makes discovery in each thread, then compare it with master thread. The discovered lists of test should be the same. Sets are not order guaranteed, so they should not be used for parametrized testing, because discovery of the tests with using xdist will fail.
This PR just converts set to dist, to eliminate issue mentioned above.
2026-01-09 15:08:40 +01:00
Andrei Chekun
21a1ff3d5c test.py: remove not supported functionality
In the current state pytest do not support the order of execution, so this parameter is removed. There is no big need in this due to the differences what pytest and test.py counted test. pytest run test functions in the threads, while test.py executed test files in the threads. That's why pytest's way is more granular and allows to fill threads better.
Remove skip node, since it already added as a pytest mark for each test in the file.
Remove pool_size, since this is not used by pytest at all. Pytest uses
xdist to set the amount of threads instead of pool_size used by test.py
2026-01-09 11:59:25 +01:00
Andrei Chekun
e8c50a5ad4 test.py: switch of execution of several test directories by test.py runner
With this commit test.py will lose ability to run tests by itself always bypassing execution to the pytest.

NOTE: this is a breaking change. From this commit, several directories
with tests will require a path to the file to launch the test.
Affected directories
test/alternator
test/broadcast_tables
test/cql
test/cqlpy
test/rest_api
2026-01-09 11:59:25 +01:00
copilot-swe-agent[bot]
8c48b82b84 test_ssl: fix indentation 2026-01-09 10:27:17 +01:00
Piotr Smaron
7016fc4835 test_ssl: improve timeout and readability
1. With this change the test really waits 10s, previously (in case
   something went wrong), the timeout could take way more than that.
2. Added `else` to above `if` to increase clarity of execution flow -
   it doesn't change logic, but makes it more clear.
2026-01-09 10:22:19 +01:00
Andrei Chekun
b546315edf test.py: fix race condition in initizlization of cqlpy tests
Fix the race condition when the process finished, while test is trying
to checks its descriptors. Now instead of failing the whole loop, it
will continue to iterate the rest of the process to find the needed
process.

Closes scylladb/scylladb#27994
2026-01-06 10:40:25 +02:00
Nadav Har'El
384e394ff0 Merge 'Add similarity functions to calculate similarity of given vectors' from Dawid Pawlik
It should be possible to return the similarity of vectors in CQL statements following the [Cassandra compatible syntax](https://cassandra.apache.org/doc/latest/cassandra/getting-started/vector-search-quickstart.html#query-vector-data-with-cql):

```
SELECT comment, similarity_cosine(comment_vector, [0.1, 0.15, 0.3, 0.12, 0.05])
    FROM cycling.comments_vs;
```

Although the calculations are slow, and we already have calculated results returned via Vector Store API,
we need the functionality as it allows us to calculate similarity of vectors not stored in vector indexes.

It will be needed for [quantization and rescoring](https://scylladb.atlassian.net/wiki/spaces/RND/pages/195985800/Quantization+and+Rescoring).

The feature is also a nice-to-have in testing as requested many times by testing and CX teams.

The optimized version utilizing already calculated distances from Vector Store without a need of rescoring will be coming soon after via https://github.com/scylladb/scylladb/pull/27991.

---

The patch adds functions:
- `similarity_cosine(<vector>, <vector>)`,
- `similarity_euclidean(<vector>, <vector>)`,
- `similarity_dot_product(<vector>, <vector>)`

Where `<vector>` is either a column of type `VECTOR<FLOAT, N>` or a vector of floats literal.

These functions can be called with every `SELECT` query, not only ANN vector queries as opposed to https://github.com/scylladb/scylladb/pull/25993.

The similarity calculations are implemented inspired by [USearch's implementation](
a2f1759910/include/usearch/index_plugins.hpp (L1304-L1385)) and made compatible with [Cassandra's documentation](https://cassandra.apache.org/doc/5.0/cassandra/developing/cql/functions.html#vector-similarity-functions).
That would guarantee the results in ScyllaDB are calculated using the exact same algorithms as used in Vector Store indexes.

---

Fixes: SCYLLADB-88
Fixes: SCYLLADB-89

New feature, should land into 2026.1

Closes scylladb/scylladb#27524

* github.com:scylladb/scylladb:
  docs: add vector similarity functions documentation
  test/cqlpy: add similarity functions correctness tests
  test/cqlpy: add similarity functions invalid call tests
  cql3: introduce similarity functions syntax
  vector_similarity_fcts: introduce similarity functions
  vector_similarity_fcts: retrieve similarity function argument types
  vector_similarity_fcts: add calculating similarity between vectors
2026-01-05 18:28:10 +02:00
Nadav Har'El
c4a9d7eb3e cql: fix DESC KEYSPACES when a "USE" is in effect
If a CQL session USEs a keyspace and then calls DESC TABLES, the user
expects to see only the tables in the chosen keyspace. However, calling
DESC KEYSPACES should still return list all the keyspaces - returning
just the USEd one is not useful - and also not what Cassandra does.
We had an xfailing test test_describe.py::test_keyspaces_with_use which
reproduces this bug (and passes on Cassandra).

In this patch we fix this bug. The fix is simple - USE should affect
DESC statements, but be ignored for DESC KEYSPACES. We can then remove
the xfail marker from the test.

The patch also includes a new test for the DESC TABLES case, where the
USE *does* have an affect. And I wanted to make sure the patch doesn't
break this case. As usual, the new test passes on both Cassandra and
ScyllaDB.

Fixes #26334

Signed-off-by: Nadav Har'El <nyh@scylladb.com>

Closes scylladb/scylladb#27971
2026-01-04 22:01:12 +02:00
Dawid Pawlik
115bd51873 test/cqlpy: add similarity functions correctness tests
Add `calculate_similarity` function for testing purposes.

Add tests checking if CQL returned values match the calculated
ones with the precision up to 5th decimal place.

The tests should also be run on Cassandra to check compatibility
with their responses.
2026-01-02 13:02:59 +01:00
Dawid Pawlik
12aa33106f test/cqlpy: add similarity functions invalid call tests
Add tests checking that calling similarity functions with:
- non-vector columns
- non-vector values
- vectors with mismatching dimensions
as arguments fails.
2026-01-02 12:49:22 +01:00
Nadav Har'El
e28df9b3d0 test: fix Python warnings in regular expressions
Like C, Python supports some escape sequences in strings such as the
familiar "\n" that converts to a newline character.
Originally, when backslash was used before a random character, for
example, "\.", Python used to just use these literal characters
backslash and dot, in the string - and not make a fuss about it.
This made it ok to use a string like "hi\.there" as a regular expression.
We have a few instances of this in our Python tests.

But recent releases of Python started to produce ugly warnings about
these cases. The error message looks like:

    SyntaxWarning: "\." is an invalid escape sequence. Such sequences
    will not work in the future. Did you mean "\\."? A raw string is
    also an option.

Indeed in most cases the easiest solution is to use a "raw string",
a string literal preceded with r. For example, r"hi\.there". In such
strings Python doesn't replace escape sequences like \n in the string,
and also leaves the \. unchanged for the regular expression to see.

So in this patch we use raw strings in all places in test/ where Python
warns have this problem.

Signed-off-by: Nadav Har'El <nyh@scylladb.com>

Closes scylladb/scylladb#27856
2025-12-31 20:44:01 +02:00
Botond Dénes
c66275e05c cql3/statements/batch_statement: make size error message more verbose
Mention the type of batch: Logged or Unlogged. The size (warn/fail on
too large size) error has different significance depending on the type.

Refs: #27605

Closes scylladb/scylladb#27664
2025-12-24 15:27:01 +02:00
Botond Dénes
b036a461b7 tools/scylla-sstable: dump-schema: incude UDT description in dump
If the table uses UDTs, include the description of these (CREATE TYPE
statement) in the schema dump. Without these the schema is not useful.

Closes scylladb/scylladb#27559
2025-12-24 14:46:52 +02:00
Nadav Har'El
74a57d2872 test/cqlpy: remove unused imports
Remove many unused "import" statements or parts of import statement.
All of them were detected by Copilot, but I verified each one manually
and prepared this patch.

Signed-off-by: Nadav Har'El <nyh@scylladb.com>

Closes scylladb/scylladb#27675
2025-12-24 13:31:41 +02:00
Nadav Har'El
f3a4af199f test/cqlpy/test_materialized_view.py: Fix for Commented-out code
This patch was suggested and prepared by copilot, I am writing the commit
message because the original one was worthless.

In commit cf138da, for an an unexplained reason, a loop waiting until the
expected value appears in a materialized view was replaced by a call for
wait_for_view_built(). The old loop code was left behind in a comment,
and this commented-out code is now bothering our AI. So let's delete the
commented-out code.

Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>

Closes scylladb/scylladb#27646
2025-12-24 10:56:23 +02:00
Nadav Har'El
e75c75f8cd test/cqlpy: fix two tests that couldn't fail because of typo
As noticed by copilot, two tests in test_guardrail_compact_storage.py
could never fail, because they used `pytest.fail` instead of the
correct `pytest.fail()` to fail. Unfortunately, Python has a footgun
where if it sees a bare function name without parenthesis, instead of
complaining it evaluates the function object and then ignores it,
and absolutely nothing happens.

So let's add the missing `()`. The test still passes, but now it at
least has a chance of failing if we have a regression.

Signed-off-by: Nadav Har'El <nyh@scylladb.com>

Closes scylladb/scylladb#27658
2025-12-24 06:49:54 +02:00
Avi Kivity
fc81983d42 test: sstable_validation_test: actually test ms version
sstable_validation_test tests the `scylla sstable validate` command
by passing it intentionally corrupted sstables. It uses an sstable
cache to avoid re-creating the same sstables. However, the cache
does not consider the sstable version, so if called twice with the
same inputs for different versions, it will return an sstable with
the original version for both calls. As a results, `ms` sstables
were not tested. Fix this bug by adding the sstable version (and
the schema for good measure) to the cache key.

An additional bug, hidden by the first, was that we corrupted the
sstable by overwriting its Index.db component. But `ms` sstables
don't have an Index.db component, they have a Partitions.db component.
Adjust the corrupting code to take that into account.

With these two fixes, test_scylla_sstable_validate_mismatching_partition_large
fails on `ms` sstables. Disable it for that version. Since it was
previously practically untested, we're not losing any coverage.

Fixing this test unblocks further work on making pytest take charge
of running the tests. pytest exposed this problem, likely by running
it on different runners (and thus reducing the effectiveness of the
cache).

Fixes #27822.

Closes scylladb/scylladb#27825
2025-12-24 06:47:31 +02:00
Avi Kivity
7586c5ccbd Merge 'system.clients: add client_options map column' from Vladislav Zolotarov
This pull request introduces a new caching mechanism for client options in the Alternator and transport layers, refactors how client metadata is stored and accessed, and extends the `system.clients` virtual table to surface richer client information. The changes improve efficiency by deduplicating commonly used strings (like driver names/versions and client options), and ensure that client data is handled in a way that's safe for cross-shard access. Additionally, the test suite and virtual table schema are updated to reflect the new client options data.

**Caching and client metadata refactoring:**

* The largest and most repeatable items in the connection state before this PR were a `driver_name` and a `driver_version` which were stored as an `sstring` object which means that the corresponding memory consumption was 16 bytes per each such value at least (the smallest size of the `seastar`'s `sstring` object) **per-connection**. In reality the driver name is usually longer than 15 characters, e.g. "ScyllaDB Python Driver" is 23 characters and this is not the longest driver name there is. In such cases the actual memory usage of a corresponding `sstring` object jumps to 8 + 4 + 1 + (string length, 23 in our example) + 1.
So, for "ScyllaDB Python Driver" it would be 37 bytes (in reality it would be a bit more due to natural alignment of other allocations since the `contents` size is not well aligned (13 bytes), but let's ignore this for now).
* These bytes add up quickly as there are more connections and, sometimes we are talking about millions of connections per-shard.
* Using a smart pointer (`lw_shared_ptr`) referencing a corresponding cached value will effectively reduce the per-connection memory usage to be 8 bytes (a size of a pointer on 64-bit CPU platform) for each such value. While storing a corresponding `sstring` value only once.
* This will would reduce the "variable" (per-connection) memory usage by **at least 50%**. And in case of "ScyllaDB Python Driver" driver version - by 78%!
* And all this for a price of a single `loading_shared_values` object **per-shard** (implements a hash table) and a minor overhead for each value **stored** in it.

* Introduced a new cache type (`client_options_cache_type`) for deduplicating and sharing client option strings, and refactored `client_data`, `client_state`, and related classes to use `foreign_ptr<std::unique_ptr<client_data>>` and cached entry types for fields like driver name, driver version, and client options. (`client_data.hh`, `service/client_state.hh`, `alternator/server.hh`, `alternator/controller.hh`, `transport/controller.hh`, `transport/protocol_server.hh`) [[1]](diffhunk://#diff-664a3b19e905481bdf8eb3843fc4d34691067bb97ab11cfd6e652e74aac51d9fR33-R36) [[2]](diffhunk://#diff-664a3b19e905481bdf8eb3843fc4d34691067bb97ab11cfd6e652e74aac51d9fL40-R56) [[3]](diffhunk://#diff-daadce1a2de3667511e59558f3a8f077b5ee30a14bcc6a99d588db90d0fcd2bdL105-R107) [[4]](diffhunk://#diff-daadce1a2de3667511e59558f3a8f077b5ee30a14bcc6a99d588db90d0fcd2bdL154-R182) [[5]](diffhunk://#diff-5fce246edf5abffb2351bd02e2eb1e9850880f7a00607ccaa90c3eee7ef57c6bL91-R92) [[6]](diffhunk://#diff-5fce246edf5abffb2351bd02e2eb1e9850880f7a00607ccaa90c3eee7ef57c6bL110-R111) [[7]](diffhunk://#diff-31730ba8e7374f784a88dc27c1512291cf73b7f24e08768f7466a3c8cfcc7a1aL96-R96) [[8]](diffhunk://#diff-19a97c0247cc08155ee49b277e43859ca32d6ef8cbff0ed7368ec5fa19e0a11eL172-R172) [[9]](diffhunk://#diff-eea7e2db5d799a25e717a72ac8ce5842bd4adb72b694d38d8f47166d9cd926faL356-R356) [[10]](diffhunk://#diff-d0b4ec3a144bbc5dc993866cf0b940850a457ff6156064f7e2b4b10ad0a95fefL80-R80) [[11]](diffhunk://#diff-4293b94c444d9bd5ecd17ce7eda8c00685d35ecf6e07f844efc91a91bbe85be1L46-R48)

* Updated the methods for setting and getting driver name, driver version, and client options in `client_state` to be asynchronous and use the new cache. (`service/client_state.hh`, `service/client_state.cc`) [[1]](diffhunk://#diff-daadce1a2de3667511e59558f3a8f077b5ee30a14bcc6a99d588db90d0fcd2bdL154-R182) [[2]](diffhunk://#diff-99634aae22e2573f38b4e2f050ed2ac4f8173ff27f0ae8b3609d1f0cc1aeb775R347-R362)

**Virtual table and API enhancements:**

* Extended the `system.clients` virtual table schema and implementation to include a new `client_options` column (a map of option key/value pairs), and updated the table population logic to use the new cached types and foreign pointers. (`db/virtual_tables.cc`) [[1]](diffhunk://#diff-05f7bff3edb39fb8759c90b445e860189f2f30e04717ed58bae42716082af3d1R752) [[2]](diffhunk://#diff-05f7bff3edb39fb8759c90b445e860189f2f30e04717ed58bae42716082af3d1L769-R770) [[3]](diffhunk://#diff-05f7bff3edb39fb8759c90b445e860189f2f30e04717ed58bae42716082af3d1L809-R816) [[4]](diffhunk://#diff-05f7bff3edb39fb8759c90b445e860189f2f30e04717ed58bae42716082af3d1L828-R879)

**API and interface changes:**

* Changed the signatures of `get_client_data` methods throughout the codebase to return vectors of `foreign_ptr<std::unique_ptr<client_data>>` instead of plain `client_data` objects, to ensure safe cross-shard access. (`alternator/controller.hh`, `alternator/controller.cc`, `alternator/server.hh`, `alternator/server.cc`, `transport/controller.hh`, `transport/protocol_server.hh`) [[1]](diffhunk://#diff-31730ba8e7374f784a88dc27c1512291cf73b7f24e08768f7466a3c8cfcc7a1aL96-R96) [[2]](diffhunk://#diff-19a97c0247cc08155ee49b277e43859ca32d6ef8cbff0ed7368ec5fa19e0a11eL172-R172) [[3]](diffhunk://#diff-5fce246edf5abffb2351bd02e2eb1e9850880f7a00607ccaa90c3eee7ef57c6bL110-R111) [[4]](diffhunk://#diff-a7e2cda866c03a75afcf3b087de1c1dcd2e7aa996214db67f9a11ed6451e596dL988-R995) [[5]](diffhunk://#diff-eea7e2db5d799a25e717a72ac8ce5842bd4adb72b694d38d8f47166d9cd926faL356-R356) [[6]](diffhunk://#diff-d0b4ec3a144bbc5dc993866cf0b940850a457ff6156064f7e2b4b10ad0a95fefL80-R80) [[7]](diffhunk://#diff-4293b94c444d9bd5ecd17ce7eda8c00685d35ecf6e07f844efc91a91bbe85be1L46-R48)

**Testing and validation:**

* Updated the Python test for the `system.clients` table to verify the new `client_options` column and its contents, ensuring that driver name and version are present in the options map. (`test/cqlpy/test_virtual_tables.py`) [[1]](diffhunk://#diff-6dd8bd4a6a82cd642252a29dc70726f89a46ceefb991c3e63fc67e283f323f03R79) [[2]](diffhunk://#diff-6dd8bd4a6a82cd642252a29dc70726f89a46ceefb991c3e63fc67e283f323f03R88-R90)

Closes scylladb/scylladb#25746

* github.com:scylladb/scylladb:
  transport/server: declare a new "CLIENT_OPTIONS" option as supported
  service/client_state and alternator/server: use cached values for driver_name and driver_version fields
  system.clients: add a client_options column
  controller: update get_client_data to use foreign_ptr for client_data
2025-12-22 20:02:40 +02:00
Botond Dénes
af5e73def9 Merge 'test/cqlpy: remove unused variables' from Nadav Har'El
These patches fix a bunch of variables defined in test/cqlpy tests, but not used. Besides wasting a few bytes on disk, these unused variables can add confusion for readers who see them and might think they have some use which they are missing.

All these unused variables were found by Copilot's "code quality" scanner, but I considered each of them, and fixed them manually.

Closes scylladb/scylladb#27667

* github.com:scylladb/scylladb:
  test/cqlpy: remove unused variables
  test/cqlpy: use unique partition in test
2025-12-22 20:02:39 +02:00
Vlad Zolotarov
85adf6bdb1 system.clients: add a client_options column
This new column is going to contain all OPTIONS sent in the
STARTUP frame of the corresponding CQL session.

The new column has a `frozen<map<text, text>>` type, and
we are also optimizing the amount of required memory for storing
corresponding keys and values by caching them on each shard level.

Signed-off-by: Vlad Zolotarov <vladz@scylladb.com>
2025-12-20 12:26:15 -05:00
Pavel Emelyanov
c4496dd63c Merge 'test/cqlpy: rename tests with duplicate name' from Nadav Har'El
When translating Cassandra's unit tests, in a couple of places I accidentally used the same name for two tests, resulting in the first of each pair to never running.

Let's fix the name of the second of the each pair to be the real name it had in the original Cassandra test.

Closes scylladb/scylladb#27644

* github.com:scylladb/scylladb:
  test/cqlpy: rename test with duplicate name
  test/cqlpy: rename test with duplicate name
2025-12-16 19:32:20 +03:00
Nadav Har'El
c58739de6a Fix for Unused local variable
Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>

Closes scylladb/scylladb#27665
2025-12-16 19:20:53 +03:00
Piotr Dulikowski
7900aa5319 Merge 'server: fix scheduling group update timing in system.clients' from Alex Dathskovsky
Previously, the scheduling_group column was updated during the switch_tenant function, which meant the update occurred only after the tenant change operation completed—updating rows one by one. With this change, the scheduling_group column is now updated before the switch_tenant logic runs, ensuring that the table reflects the correct scheduling groups for all rows as early as possible.

fixes: #26060
fixes: #27295

backport: not required
this is a minor bug fix. Internal logic worked but the user couldnt see the change in the table if they would read the system.clients table

Closes scylladb/scylladb#26404

* github.com:scylladb/scylladb:
  test: cqlpy: Remove test_switch_tenants and add test in cluster testing. The test needs to run twice, in two separate Scylla runs, using two different modes: gossip and raft. The cluster framework supports this setup, while cqlpy only runs against Scylla instances in raft mode. Therefore, the test was moved from cqlpy to the cluster-based framework. This commit both adds the test in cluster/ and removes the old version in cqlpy/.
  server: Refactor update_control_connection_scheduling_group functionality This refactoring moves the logic that retrieves the scheduling group for driver_service_level_name out of switch_tenant. This change is possible because the scheduling group for the driver is retrieved from a map (LOOKUP). The lookup function is fully synchronized, non-coroutine, and returns immediately. For that reason, it’s better to perform this lookup outside of the switch_tenant function.
  server: Refactor scheduling group update functionality. This change generalizes the scheduling-group update functionality and removes some copy-paste code, improving overall readability and maintainability. To achieve this, capturing lambdas were introduced. As a result, self-deducing this was added to those lambdas to avoid coroutine-related issues (“coroutine fiasco”).
  server: Fix switch_tenant problem, When running on a V2 server, service-level data comes from service level cache. Because of this, we can use synchronized function to get the schedualing group. Since we are transitioning to a Raft-based architecture where all servers will be V2, we can safely implement this fix specifically for that case. This change adds get_cached_user_scheduling_group functionality and moves its usage out of switch_tenant function in update_scheduling_group_v2 usage.
  server: Add update_service_level_scheduling_group_v1 functions to create placehholder for functionality that will introduce v2 implementation. The new functionality will allow usage of service level cache
2025-12-16 15:39:49 +01:00
Dawid Mędrek
df0830044d cql3: Extend DESC INDEX by view properties
We're extending the logic of DESCRIBE INDEX to include properties of the
underlying materialized view. Tests are provided to ensure the
implementation works as intended.
2025-12-16 11:43:38 +01:00
Dawid Mędrek
d0a42852c0 cql3: Forbid using CLUSTERING ORDER BY when creating index
This is a temporary solution as handling this property may require
a bit more attention or at least a bit more focus. For now, let's
forbid using it so it's clear it won't get applied. A simple test
is provided to cover it.

We document the restriction.
2025-12-16 11:43:38 +01:00
Dawid Mędrek
6541362a0b cql3: Extend CREATE INDEX by MV properties
After the previous patch that extended the grammar and provided
basic functionalities to accommodate properties of materialized views
in indexes, this commit takes another step and actually applies them
to the underlying view when it's being created.

We're providing validation tests for each property, with the single
exception of CLUSTERING ORDER BY. That one will be handled separately
in an upcoming commit.

We also update the user documentation.
2025-12-16 11:43:38 +01:00
Nadav Har'El
4e106b9820 test/cqlpy: remove unused variables
Copilot detected a few cases of cqlpy tests setting a variable which
they don't use. In all the cases in this patch, we can just remove
the variable. Although the AI found all these unused variables, I
verified each case carefully before changing it in this patch.

Signed-off-by: Nadav Har'El <nyh@scylladb.com>
2025-12-15 18:11:04 +02:00
Nadav Har'El
4fa4f40712 test/cqlpy: use unique partition in test
It is traditional to use a unique (or random) partition key in cqlpy
tests, to allow multiple tests to share the same table and make the test
suite a bit faster. One of the tests, test_multi_column_relation_desc,
set up a unique key "k", but then forgot to use it and used partition
key 0 instead. Fix the test to use this k.

This problem was spotted by Copilot, who saw the unused variable k.

Signed-off-by: Nadav Har'El <nyh@scylladb.com>
2025-12-15 17:08:51 +02:00
Nadav Har'El
ccacea621f test/cqlpy: fix flaky test test_view_in_system_tables
The cqlpy test test_materialized_view.py::test_view_in_system_tables
checks that the system table "system.built_views" can inform us that
a view has been built. This test was flaky, starting to fail quite
often recently, and this patch fixes the problem in the test.

For historic reasons  this test began by calling a utility function
wait_for_view_built() - which uses a different system table,
system_distributed.view_build_status, to wait until the view was built.
The test then immediately tries to verify that also system.built_views
lists this view.

But there is no real reason why we could assume - or want to assume -
that these two tables are updated in this order, or how much time
passed between the two tables being changed. The authors of this
test already acknowledged there is a problem - they included a hack
purporting to be a "read barrier" that claimed to solve this exact
problem - but it seems it doesn't, or at least no longer does after
recent changes to the view builder's implementation.

The solution is simple - just remove the call to wait_for_view_built()
and the "hack" after it. We should just wait in a loop (until a timeout)
for the system table that we really wanted to check - system.built_views.
It's as simple as that. No need for any other assumptions or hacks.

Fixes #27296

Signed-off-by: Nadav Har'El <nyh@scylladb.com>

Closes scylladb/scylladb#27626
2025-12-15 15:29:08 +03:00
Nadav Har'El
f287484f4d test/cqlpy: rename test with duplicate name
When translating Cassandra's test validation/operations/CreateTest.java
I accidentally used the same name for two tests, resulting in the first
of them never being run.

Let's fix the name of the second of the two to be the real name it had
in the original Cassandra test.

After this patch pytest reports 16 tests in this file, instead of 15
before this patch. The previously-ignored test was correct, and it
now passes in both Scylla and Cassandra.

Signed-off-by: Nadav Har'El <nyh@scylladb.com>
2025-12-15 14:19:24 +02:00
Nadav Har'El
a9442e6d56 test/cqlpy: rename test with duplicate name
When translating Cassandra's test validation/operations/DeleteTest.java
I accidentally used the same name for two tests, resulting in the first
of them never being run.

Let's fix the name of the second of the two to be the real name it had
in the original Cassandra test.

After this patch pytest reports 52 tests in this file, instead of 51
before this patch. The previously-ignored test was correct, and it
now passes in both Scylla and Cassandra.

Signed-off-by: Nadav Har'El <nyh@scylladb.com>
2025-12-15 12:02:59 +02:00
Michał Hudobski
12483d8c3c vector_search: throw an error when we restrict primary in vector search
We currently allow restrictions on single column primary key,
but we ignore the restriction and return all results.
This can confuse the users. We change it so such a restriction
will throw an error and add a test to validate it.

Fixes: VECTOR-331

Closes scylladb/scylladb#27143
2025-12-15 09:45:56 +02:00
Alex
d21faab9dc test: cqlpy: Remove test_switch_tenants and add test in cluster testing. The test needs to run twice, in two separate Scylla runs, using two different modes: gossip and raft.
The cluster framework supports this setup, while cqlpy only runs against Scylla instances in raft mode.
Therefore, the test was moved from cqlpy to the cluster-based framework.
This commit both adds the test in cluster/ and removes the old version in cqlpy/.
2025-12-14 18:46:06 +02:00
copilot-swe-agent[bot]
77ee7f3417 Revert "Merge 'Add option to use sstable identifier in snapshot' from Benny Halevy"
This reverts commit 8192f45e84.

The merge exposed a bug where truncate (via drop) fails and causes Raft
errors, leading to schema inconsistencies across nodes. This results in
test_table_drop_with_auto_snapshot failures with 'Keyspace test does not exist'
errors.

The specific problematic change was in commit 19b6207f which modified
truncate_table_on_all_shards to set use_sstable_identifier = true. This
causes exceptions during truncate that are not properly handled, leading
to Raft applier fiber stopping and nodes losing schema synchronization.
2025-12-12 03:55:13 +00:00
Nadav Har'El
8822c23ad4 Merge 'test: cqlpy: test_protocol_exceptions.py: increase cpp exceptions thr…' from Dario Mirovic
…eshold

The initial problem:

Some of the tests in test_protocol_exceptions.py started failing. The failure is on the condition that no more than `cpp_exception_threshold` happened.

Test logic:

These tests assert that specific code paths do not throw an exception anymore. Initial implementation ran a code path once, and asserted there were 0 exceptions. Sometimes an exception or several can occur, not directly related to the code paths the tests check, but those would fail the tests.

The solution was to run the tests multiple times. If there is a regression, there would be at least as many exceptions thrown as there are test runs. If there is no regression, a few exceptions might happen, up to 10 per 100 test runs. I have arbitrarily chosen `run_count = 100` and `cpp_exception_threshold = 10` values.

Note that the exceptions are counted per shard, not per code path.

The new problem:

The occassional exceptions thrown by some parts of the server now throw a bit more than before. Based on the logs linked on the issues, it is usually 12.

There are possibly multiple ways to resolve the issue. I have considered logging exceptions and parsing them. I would have to filter exception logs only for wanted exceptions. However, if a new, different exception is introduced, it might not be counted.

Another approach is to just increase the threshold a bit. The issue of throwing more exceptions than before in some other server modules should be addressed by a set of tests for that module, just like these tests check protocol exceptions, not caring who used protocol check code paths.

For those reasons, the solution implemented here is to increase `cpp_exception_threshold` to `20`. It will not make the tests unreliable, because, as mentioned, if there is a regression, there would be at least `run_count` exceptions per `run_count` test runs (1 exception per single test run).

Still, to make "background exceptions" occurence a bit more normalized, `run_count` too is doubled, from `100` to `200`. At the first glance this looks like nothing is changed, but actually doubling both run count and exception threshold here implies that the burst does not scale as much as run count, it is just that the "jitter" is bigger than the old threshold.

Also, this patch series enables debug logging for `exception` logger. This will allow us to inspect which exceptions happened if a protocol exceptions test fails again.

Fixes #27247
Fixes #27325

Issue observed on master and branch-2025.4. The tests, in the same form, exist on master, branch-2025.4, branch-2025.3, branch-2025.2, and branch-2025.1. Code change is simple, and no issue is expected with backport automation. Thus, backports for all the aforementioned versions is requested.

Closes scylladb/scylladb#27412

* github.com:scylladb/scylladb:
  test: cqlpy: test_protocol_exceptions.py: enable debug exception logging
  test: cqlpy: test_protocol_exceptions.py: increase cpp exceptions threshold
2025-12-10 10:53:30 +02:00
Dario Mirovic
c30b326033 test: cqlpy: test_protocol_exceptions.py: enable debug exception logging
Enable debug logging for "exception" logger inside protocol exception tests.
The exceptions will be logged, and it will be possible to see which ones
occured if a protocol exceptions test fails.

Refs #27272
Refs #27325
2025-12-09 01:35:42 +01:00
Dario Mirovic
807fc68dc5 test: cqlpy: test_protocol_exceptions.py: increase cpp exceptions threshold
The initial problem:

Some of the tests in test_protocol_exceptions.py started failing. The failure is
on the condition that no more than `cpp_exception_threshold` happened.

Test logic:

These tests assert that specific code paths do not throw an exception anymore.
Initial implementation ran a code path once, and asserted there were 0 exceptions.
Sometimes an exception or several can occur, not directly related to the code paths
the tests check, but those would fail the tests.

The solution was to run the tests multiple times. If there is a regression, there
would be at least as many exceptions thrown as there are test runs. If there is no
regression, a few exceptions might happen, up to 10 per 100 test runs.
I have arbitrarily chosen `run_count = 100` and `cpp_exception_threshold = 10` values.

Note that the exceptions are counted per shard, not per code path.

The new problem:

The occassional exceptions thrown by some parts of the server now throw a bit more
than before. Based on the logs linked on the issues, it is usually 12.

There are possibly multiple ways to resolve the issue. I have considered logging
exceptions and parsing them. I would have to filter exception logs only for wanted
exceptions. However, if a new, different exception is introduced, it might not be
counted.

Another approach is to just increase the threshold a bit. The issue of throwing
more exceptions than before in some other server modules should be addressed by
a set of tests for that module, just like these tests check protocol exceptions,
not caring who used protocol check code paths.

For those reasons, the solution implemented here is to increase `cpp_exception_threshold`
to `20`. It will not make the tests unreliable, because, as mentioned, if there is a
regression, there would be at least `run_count` exceptions per `run_count` test runs
(1 exception per single test run).

Still, to make "background exceptions" occurence a bit more normalized, `run_count` too
is doubled, from `100` to `200`. At the first glance this looks like nothing is changed,
but actually doubling both run count and exception threshold here implies that the
exception burst does not scale as much as run count, it is just that the "jitter" is
bigger than the old threshold.

Fixes #27247
Fixes #27325
2025-12-09 01:34:48 +01:00
Benny Halevy
ff52550739 nodetool: snapshot: add --use-sstable-identifier option
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2025-12-04 11:57:39 +02:00
Pavel Emelyanov
6ae72ed134 test: Reuse S3 fixtures facilities in cqlpy/test_tools.py
Creating endpoint conf can be made with the s3_server method
Getting boto3 resource from s3_server itself is also possible

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

Closes scylladb/scylladb#27380
2025-12-03 16:32:54 +02:00
Botond Dénes
357f91de52 Revert "Merge 'db/config: enable ms sstable format by default' from Michał Chojnowski"
This reverts commit b0643f8959, reversing
changes made to e8b0f8faa9.

The change forgot to update
sstables_manager::get_highest_supported_format(), which results in
/system/highest_supported_sstable_version still returning me, confusing
and breaking tests.

Fixes: scylladb/scylla-dtest#6435

Closes scylladb/scylladb#27379
2025-12-02 14:38:56 +02:00
Dawid Mędrek
b76af2d07f cql3: Improve errors when manipulating default service level
Before this commit, any attempt to create, alter, attach, or drop
the default service level would result in a syntax error whose
error message was unclear:

```
cqlsh> attach service level default to cassandra;
SyntaxException: line 1:21 no viable alternative at input 'default'
```

The error stems from the grammar not being able to parse `default`
as a correct service level name. To fix that, we cover it manually.
This way, the grammar accepts it and we can process it in Scylla.

The reason why we'd like to cover the default service level is that
it's an actual service level that the user should reference. Getting
a syntax error is not what should happen. Hence this fix.

We validate the input and if the given role is really the default
service level, we reject the query and provide an informative error
message.

Two validation tests are provided.

Fixes scylladb/scylladb#26699

Closes scylladb/scylladb#27162
2025-11-28 15:32:37 +03:00
Botond Dénes
584f4e467e tools/scylla-sstable: introduce the dump-schema command
There is a limited number of ways to obtain the schema of a table:
1) Use DESCRIBE TABLE in cqlsh
2) Find the schema definition in the code (for system tables)
3) Ask support/user to provide schema
4) Piece together the schema definition from the system tables

Option (1) is the most convenient but requires access to live cluster.
(2) is limited to system tables only.
When investigating issues for customers, we have to rely on (3) and this
often adds communication round-trips and delays. (4) requires knowledge
of ScyllaDB internals and access to system tables.

The new dump-schema commands provides a convenient way to obtain the
schema of tables, given that there is access to either an sstable or the
system tables. It can dump the schema of system tables without either.

Closes scylladb/scylladb#26433
2025-11-25 20:32:36 +03:00
Karol Nowacki
ca62effdd2 vector_search: Restrict vector index tests to tablets only
Vector indexes are going to be supported only for tablets (see VECTOR-322).
As a result, tests using vector indexes will be failing when run with vnodes.

This change ensures tests using vector indexes run exclusively with tablets.

Fixes: VECTOR-49

Closes scylladb/scylladb#26843
2025-11-25 09:26:16 +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