Commit Graph

235 Commits

Author SHA1 Message Date
Botond Dénes
5998a859f7 tombstone_gc: allow use of repair-mode for RF=1 tables
Modify the methods which calculate the default gc mode as well as that
which validates whether repair-mode can be used at all, so both accepts
use of repair-mode on RF=1 tables.

This de-facto changes the default tombstone-gc to repair-mode for all
tables. Documentation is updated accordingly.

Some tests need adjusting:
* cqlpy/test_select_from_mutation_fragments.py: disable GC for some test
  cases because this patch makes tombstones they write subject to GC
  when using defaults.
* test/cluster/test_mv.py::test_mv_tombstone_gc_not_inherited used
  repair-mode as a non-default for the base table and expected the MV to
  revert to default. Another mode has to be used as the non-default
  (immediate).
* test/cqlpy/test_tools.py::test_scylla_sstable_dump_schema: don't
  compare tombstone_gc schema extension when comparing dumped schema vs.
  original. The tool's schema loader doesn't have access to the keyspace
  definition so it will come up with different defaults for
  tombstone-gc.
* test/boost/row_cache_test.cc::test_populating_cache_with_expired_and_nonexpired_tombstones
  sets tombstone expiry assuming the tombstone-gc timeout-mode default.
  Change the CREATE TABLE statement to set the expected mode.
2026-03-04 09:44:24 +02:00
Piotr Dulikowski
44c605e59c Merge 'Fix the types of change events in Alternator Streams' from Piotr Wieczorek
This patch increases the compatibility with DynamoDB Streams by integrating the DynamoDB's event type rules (described in https://github.com/scylladb/scylladb/issues/6918) into Alternator. The main changes are:
- introduce a new flag `alternator_streams_strict_compatibility`, meant as a guard of performance-intensive operations that increase the compatibility with DynamoDB Streams. If enabled, Alternator always performs a RBW before a data-modifying operation, and propagates its result to CDC. Then, the old item is compared to the new one, to determine the mutation type (INSERT vs MODIFY). This option is a no-op for tables with disabled Alternator Streams,
- reduce splitting of simple Alternator mutations,
- correctly distinguish event types described in #6918, except for item deletes. Deleting a missing item with DeleteItem, BatchWriteItem, or a missing field with UpdateItem still emit REMOVEs.

To summarize, the emitted events of the data manipulation operations should be as follows:
- DeleteItem/BatchWriteItem.DeleteItem of existing item: REMOVE (OK)
- DeleteItem of nonexistent item: nothing (OK)
- BatchWriteItem.DeleteItem of nonexistent item: nothing (OK)
- PutItem/UpdateItem/BatchWriteItem.PutItem of existing and not equal item: MODIFY (OK)
- PutItem/UpdateItem/BatchWriteItem.PutItem of existing and equal item: nothing (OK)
- PutItem/UpdateItem/BatchWriteItem.PutItem of nonexistent item: INSERT (OK)

No backport is necessary.

Refs https://github.com/scylladb/scylladb/pull/26149
Refs https://github.com/scylladb/scylladb/pull/26396
Refs https://github.com/scylladb/scylladb/issues/26382
Fixes https://github.com/scylladb/scylladb/issues/6918

Closes scylladb/scylladb#26121

* github.com:scylladb/scylladb:
  test/alternator: Enable the tests failing because of #6918
  alternator, cdc: Don't emit events for no-op removes
  alternator, cdc: Don't emit an event for equal items
  alternator/streams, cdc: Differentiate item replace and item update in CDC
  alternator: Change the return type of rmw_operation_return
  config: Add alternator_streams_strict_compatibility flag
  cdc: Don't split a row marker away from row cells
2025-11-30 07:20:22 +01:00
Michael Litvak
868ac42a8b tombstone_gc: don't use 'repair' mode for colocated tables
For tables of special types that can be located: MV, CDC, and paxos
table, we should not use tombstone_gc=repair mode because colocated
tablets are never repaired, hence they will not have repair_time set and
will never be GC'd using 'repair' mode.
2025-11-25 09:15:46 +01:00
Dawid Mędrek
0602afc085 cdc: Preserve properties when reattaching log table
When we enable CDC on a table, Scylla creates a log table for it.
It has default properties, but the user may change them later on.
Furthermore, it's possible to detach that log table by simply
disabling CDC on the base table:

```cql
/* Create a table with CDC enabled. The log table is created. */
CREATE TABLE ks.t (pk int PRIMARY KEY) WITH cdc = {'enabled': true};

/* Detach the log table. */
ALTER TABLE ks.t WITH cdc = {'enabled': false};

/* Modify a property of the log table. */
ALTER TABLE ks.t_scylla_cdc_log WITH bloom_filter_fp_chance = 0.13;
```

The log table can also be reattached by enabling CDC on the base table
again:

```cql
/* Reattach the log table */
ALTER TABLE ks.t WITH cdc = {'enabled': true};
```

However, because the process of reattachment goes through the same
code that created it in the first place, the properties of the log
table are rolled back to their default values. This may be confusing
to the user and, if unnoticed, also have other consequences, e.g.
affecting performance.

To prevent that, we ensure that the properties are preserved.

A reproducer test,
`test_log_table_preserves_properties_after_reattachment`, has been
provided to verify that the changes are correct. It fails before this
commit.

Another test, `test_log_table_preserves_id_after_reattachment`, has
also been added because the current implementation sets properties
and the ID separately.

Fixes scylladb/scylladb#25523
2025-11-17 11:56:30 +01:00
Dawid Mędrek
10975bf65c cdc: Extract creating columns in CDC log table to dedicated function
We extract the portion of the code responsible for creating columns
in a CDC log table to a separate, dedicated function. This should
improve the overall readability of the function (and also making it
very short now).
2025-11-17 11:54:48 +01:00
Dawid Mędrek
8bf09ac6f7 cdc: Extract default properties of CDC log tables to dedicated function
We extract the portion of the code responsible for setting the default
properties of a CDC log table to a separate function. This should
improve the overall readability of the function. Also, it should be
helpful when modifying the code later on in this commit series.
2025-11-17 11:50:35 +01:00
Michael Litvak
039323d889 cdc: check if recreating a column too soon
When we drop a column from a CDC log table, we set the column drop
timestamp a few seconds into the future. This can cause unexpected
problems if a user tries to recreate a CDC column too soon, before
the drop timestamp has passed.

To prevent this issue, when creating a CDC column we check its
creation timestamp against the existing drop timestamp, if any, and
fail with an informative error if the recreation attempt is too soon.
2025-11-13 17:00:07 +01:00
Michael Litvak
48298e38ab cdc: set column drop timestamp in the future
When dropping a column from a CDC log table, set the column drop
timestamp several seconds into the future.

If a value is written to a column concurrently with dropping that
column, the value's timestamp may be after the column drop timestamp. If
this value is also flushed to an SSTable, the SSTable would be
corrupted, because it considers the column missing after the drop
timestamp and doesn't allow values for it.

While this issue affects general tables, it especially impacts CDC tables
because this scenario can occur when writing to a table with CDC preimage
enabled while dropping a column from the base table. This happens even if
the base mutation doesn't write to the dropped column, because CDC log
mutations can generate values for a column even if the base mutation doesn't.
For general tables, this issue can be avoided by simply not writing to a
column while dropping it.

We fix this for the more problematic case of CDC log tables by setting
the column drop timestamp several seconds into the future, ensuring that
writes concurrent with column drops are much less likely to have
timestamps greater than the column drop timestamp.

Fixes scylladb/scylladb#26340
2025-11-13 16:59:43 +01:00
Michael Litvak
eefae4cc4e migration_manager: pass timestamp to pre_create
pass the write timestamp as parameter to the
on_pre_create_column_families notification.
2025-11-13 16:59:43 +01:00
Piotr Dulikowski
2e5eb92f21 Merge 'cdc: use CDC schema that is compatible with the base schema' from Michael Litvak
When generating CDC log mutations for some base mutation, use a CDC schema that is compatible with the base schema.

The compatible CDC schema has for every base column a corresponding CDC column with the same name. If using a non-compatible schema, we may encounter a situation, especially during ALTER, that we have a mutation with a base column set with some value, but the CDC schema doesn't have a column by that name. This would cause the user request to fail with an error.

We add to the schema object a schema_ptr that for CDC-enabled tables points to the schema object of the CDC table that is compatible with the schema. It is set by the schema merge algorithm when creating the schema for a table that is created or altered. We use the fact that a base table and its CDC table are created and altered in the same group0 operation, and this way we can find and set the cdc schema for a base table.

When transporting the base schema as a frozen schema between shards, we transport with it the frozen cdc schema as well.

The patch starts with a series of refactoring commits that make extending the frozen schema easier and cleans up some duplication in the code about the frozen schema. We combine the two types `frozen_schema_with_base_info` and `view_schema_and_base_info` to a single type `extended_frozen_schema` that holds a frozen schema with additional data that is not part of the schema mutations but needs to be transported with it to unfreeze it - base_info, and the frozen cdc schema which is added in a later commit.

Fixes https://github.com/scylladb/scylladb/issues/26405

backport not needed - enhancement

Closes scylladb/scylladb#24960

* github.com:scylladb/scylladb:
  test: cdc: test cdc compatible schema
  cdc: use compatiable cdc schema
  db: schema_applier: create schema with pointer to CDC schema
  db: schema_applier: extract cdc tables
  schema: add pointer to CDC schema
  schema_registry: remove base_info from global_schema_ptr
  schema_registry: use extended_frozen_schema in schema load
  schema_registry: replace frozen_schema+base_info with extended_frozen_schema
  frozen_schema: extract info from schema_ptr in the constructor
  frozen_schema: rename frozen_schema_with_base_info to extended_frozen_schema
2025-11-13 10:11:54 +01:00
Piotr Wieczorek
a32e8091a9 alternator, cdc: Don't emit an event for equal items
This commit adds a function that compares split mutations with the
`row_state`, that was selected as a preimage or propagated through
cdc options by a caller. If the items are equal, the corresponding log
row isn't generated. The result being that creating an item with
BatchWriteItem, PutItem, or UpdateItem doesn't emit an INSERT/MODIFY
event if exactly identical item already exists.

Comparing the items may be costly, so this logic is controlled by
`alternator_streams_compabitiblity` flag.

This commit handles the following cases:
- `PutItem/UpdateItem/BatchWriteItem.PutItem of an existing and equal
  item: nothing`
2025-10-30 08:38:30 +01:00
Piotr Wieczorek
8c2f60f111 alternator/streams, cdc: Differentiate item replace and item update in CDC
This commit improves compatibility with DynamoDB streams by changing the
emitted events when creating/updating an item. Replace/update operations
of an existing item emit a MODIFY, whereas replacing/updating a missing
item results in an INSERT. If the state of the item doesn't change after
applying the operation, no event is emitted.

This commit handles the following cases:
- `PutItem/UpdateItem/BatchWriteItem.PutItem of an existing and not equal item: MODIFY`
- `PutItem/UpdateItem/BatchWriteItem.PutItem of a nonexistent item: INSERT`

Refs https://github.com/scylladb/scylladb/issues/6918
2025-10-30 07:40:31 +01:00
Piotr Wieczorek
e3fde8087a cdc: Don't split a row marker away from row cells
CDC log table records a mutation as a sequence of log rows that record
an atomic change (i.e. a row marker, tombstones, etc.), whereas a
mutation in Alternator Streams always appears as a single log row. The
type of operation is determined based on the type of the last log row in
CDC.

As a result, updates that create a row always appeared to Alternator
Streams as an update (row marker + data), rather than an insert. This
commit makes them a single log row. Its operation type is insert if it
contains a row marker, and an update otherwise, which gives results
consistent with DynamoDB Streams.
2025-10-30 07:40:31 +01:00
Piotr Wieczorek
2812e67f47 cdc: Emit a preimage for non-clustered tables
Until this patch, CDC haven't fetched a preimage for mutations
containing only a partition tombstone. Therefore, single-row deletions
in a table witout a clustering key didn't include a preimage, which was
inconsistent with single-row clustered deletions. This commit addresses
this inconsistency.

Second reason is compatibility with DynamoDB Streams, which doesn't
support entire-partition deletes. Alternator uses partition tombstones
for single-row deletions, though, and in these cases the 'OldImage' was
missing from REMOVE records.

Fixes https://github.com/scylladb/scylladb/issues/26382

Closes scylladb/scylladb#26578
2025-10-29 17:54:58 +02:00
Radosław Cybulski
621e88ce52 Fix spelling errors
Closes scylladb/scylladb#26652
2025-10-22 16:46:31 +02:00
Michael Litvak
448e14a3b7 cdc: use compatiable cdc schema
in the CDC log transformer, when augmenting a base mutation, use the CDC
log schema that is compatible with the base schema, if set.

Now that the base schema has a pointer to its CDC schema, we can use it
instead of getting the current schema from the db, which may not be
compatible with the base schema.

The compatible CDC schema may not be set if the cluster is not using
raft mode for schema. In this case, we maintain the previous behavior.
2025-10-21 14:14:33 +02:00
Piotr Wieczorek
a3ec6c7d1d alternator/streams: Support userIdentity field for TTL deletions
UserIdentity is a map of two fields in GetRecords responses, which
always has the same value. It may be missing, or contain a constant
object with value `{"type": "Service", "principalId":
"dynamodb.amazonaws.com"}`. Currently, the latter is set only for
`REMOVE`s triggered by TTL.

This commit introduces two new CDC operation types: `service_row_delete`
and `service_partition_delete`, emitted in place of `row_delete` and
`partition_delete`. Alternator Streams treats them as regular `REMOVE`s,
but in addition adds the `userIdentity` field to the record.

This change may break existing Scylla libraries for reading raw CDC
tables, but we doubt that anybody has this use case.

Refs https://github.com/scylladb/scylladb/pull/26149
Refs https://github.com/scylladb/scylladb/pull/26121
Fixes https://github.com/scylladb/scylladb/issues/11523

Closes scylladb/scylladb#26460
2025-10-20 17:15:59 +02:00
Tomasz Grabiec
c4a87453a2 Merge 'Add experimental feature flag for strongly consistent tables and extend kesypace creation syntax to allow specifying consistency mode.' from Gleb Natapov
The series adds an experimental flag for strongly consistent tables  and extends "CREATE KEYSPACE" ddl with `consistency` option that allows specifying the consistency mode for the keyspace.

Closes scylladb/scylladb#26116

* github.com:scylladb/scylladb:
  schema: Allow configuring consistency setting for a keyspace
  db: experimental consistent-tablets option
2025-10-16 21:48:06 +02:00
Gleb Natapov
c255740989 schema: Allow configuring consistency setting for a keyspace
We want to add strongly consistent tables as an option. We will have
two kind of strongly consistent tables: globally consistent and locally
consistent. The former means that requests from all DCs will be globally
linearisable while the later - only requests to the same DCs will be
linearisable.  To allow configuring all the possibilities the patch
adds new parameter to a keyspace definition "consistency" that can be
configured to be `eventual`, `global` or `local`. Non eventual setting
is supported for tablets enabled keyspaces only. Since we want to start
with implementing local consistency configuring global consistency will
result in an error for now.
2025-10-16 13:34:49 +03:00
Piotr Wieczorek
d4581cc442 cdc: Support prefetched preimages
This commit adds support to pass a preimage selected by an upper layer
to CDC. The responsibility for the correctness of the preimage (i.e. the
selected columns, whether it's up to date, etc.) lies with the caller.
It may be improved in the future by validating the preimage, e.g. by
"slicing" the received preimage to the necessary columns.

The motivation behind this change was to reduce the number of
read-before-writes and avoid reading the row twice for Alternator
Streams in an increased compatibility mode with DynamoDB. This is to be
added in a following commit. Until now, this commit should be a no-op.
2025-10-14 07:29:07 +02:00
Piotr Wieczorek
2c1e699864 cdc, storage: Add a struct to pass per-mutation options to CDC
This will allow us to communicate with CDC from higher layers. We plan
to use it to reduce the number of read-before-writes with preimages by
passing the row selected in upper layers.
2025-10-09 12:28:10 +02:00
Benny Halevy
da6e2fdb1b locator: Pass topology to replication strategy constructor 2025-10-01 16:06:28 +02:00
Botond Dénes
86ed627fc4 compaction: move code to namespace compaction
The namespace usage in this directory is very inconsistent, with files
and classes scattered in:
* global namespace
* namespace compaction
* namespace sstables

With cases, where all three used in the same file. This code used to
live in sstables/ and some of it still retains namespace sstables as a
heritage of that time. The mismatch between the dir (future module) and
the namespace used is confusing, so finish the migration and move all
code in compaction/ to namespace compaction too.

This patch, although large, is mechanic and only the following kind of
changes are made:
* replace namespace sstable {} with namespace compaction {}
* add namespace compaction {}
* drop/add sstables::
* drop/add compaction::
* move around forward-declarations so they are in the correct namespace
  context

This refactoring revealed some awkward leftover coupling between
sstables and compaction, in sstables/sstable_set.cc, where the
make_sstable_set() methods of compaction strategies are implemented.
2025-09-25 15:03:56 +03:00
Piotr Dulikowski
5f55787e50 Merge 'CDC with tablets' from Michael Litvak
initial implementation to support CDC in tablets-enabled keyspaces.

The design is described in https://docs.google.com/document/d/1qO5f2q5QoN5z1-rYOQFu6tqVLD3Ha6pphXKEqbtSNiU/edit?usp=sharing
It is followed closely for the most part except "Deciding when to change streams" - instead, streams are changed synchronously with tablet split / merge.
Instead of the stream switching algorithm with the double writes, we use a scheme similar to the previous method for vnodes - we add the new streams with timestamp that is sufficiently far into the future.

In this PR we:
* add new group0-based internal system tables for tablet stream metadata and loading it into in-memory CDC metadata
* add virtual tables for CDC consumers
* the write coordinator chooses a stream by looking up the appropriate stream in the CDC metadata
* enable creating tables with CDC enabled in tablets-enabled keyspaces. tablets are allocated for the CDC table, and a stream is created per each tablet.
* on tablet resize (split / merge), the topology coordinator creates a new stream set with a new stream for each new tablet.
* the cdc tablets are co-located with the base tablets

Fixes https://github.com/scylladb/scylladb/issues/22576

backport not needed - new feature

update dtests: https://github.com/scylladb/scylla-dtest/pull/5897
update java cdc library: https://github.com/scylladb/scylla-cdc-java/pull/102
update rust cdc library: https://github.com/scylladb/scylla-cdc-rust/pull/136

Closes scylladb/scylladb#23795

* github.com:scylladb/scylladb:
  docs/dev: update CDC dev docs for tablets
  doc: update CDC docs for tablets
  test: cluster_events: enable add_cdc and drop_cdc
  test/cql: enable cql cdc tests to run with tablets
  test: test_cdc_with_alter: adjust for cdc with tablets
  test/cqlpy: adjust cdc tests for tablets
  test/cluster/test_cdc_with_tablets: introduce cdc with tablets tests
  cdc: enable cdc with tablets
  topology coordinator: change streams on tablet split/merge
  cdc: virtual tables for cdc with tablets
  cdc: generate_stream_diff helper function
  cdc: choose stream in tablets enabled keyspaces
  cdc: rename get_stream to get_vnode_stream
  cdc: load tablet streams metadata from tables
  cdc: helper functions for reading metadata from tables
  cdc: colocate cdc table with base
  cdc: remove streams when dropping CDC table
  cdc: create streams when allocating tablets
  migration_listener: add on_before_allocate_tablet_map notification
  cdc: notify when creating or dropping cdc table
  cdc: move cdc table creation to pre_create
  cdc: add internal tables for cdc with tablets
  cdc: add cdc_with_tablets feature flag
  cdc: add is_log_schema helper
2025-09-18 13:39:37 +02:00
Ernest Zaslavsky
54aa552af7 treewide: Move type related files to a type directory As requested in #22110, moved the files and fixed other includes and build system.
Moved files:
- duration.hh
- duration.cc
- concrete_types.hh

Fixes: #22110

This is a cleanup, no need to backport

Closes scylladb/scylladb#25088
2025-09-17 17:32:19 +03:00
Michael Litvak
1fc3273b27 cdc: enable cdc with tablets
Allow to create CDC tables in a tablets-enabled keyspace when all nodes
in the cluster support the cdc_with_tablets feature.

Fixes scylladb/scylladb#22576
2025-09-17 14:47:12 +02:00
Michael Litvak
5f6bb0af9d cdc: choose stream in tablets enabled keyspaces
When choosing a CDC stream to generate CDC log writes to, if the
keyspace uses tablets, we need to choose a stream according to the
relevant metadata which is specific to tablets-enabled keyspaces.

We define the method get_tablet_stream that given a table, write
timestamp, and token, returns the stream that the log entry should
be written to.

The method works by looking up the stream metadata of the table, then
finding the relevant stream set by timestamp, and finally finding
the stream that covers the token range that contains the token.
2025-09-17 14:47:12 +02:00
Michael Litvak
28cdd81ef0 cdc: rename get_stream to get_vnode_stream
the get_stream method is relevant only for vnode-based keyspaces. next
we will introduce a new method to get a stream in a tablets-based
keyspace. prepare for this by renaming get_stream to get_vnode_stream.
2025-09-17 14:47:12 +02:00
Michael Litvak
9ef0862155 cdc: remove streams when dropping CDC table
When dropping a CDC log table in a tablets-enabled keyspace, remove all
metadata about the table's CDC streams from the internal CDC tables,
since the streams can't be read anymore.

Similarly, when dropping a tablets-enabled keyspace, remove metadata of
all streams belonging to tables in the keyspace.
2025-09-17 14:47:12 +02:00
Michael Litvak
ed25e420f8 cdc: create streams when allocating tablets
When allocating tablets for a CDC table, create the initial CDC stream
set. We create one stream per each tablet, each stream covering the
corresponding token range.
2025-09-17 14:47:12 +02:00
Michael Litvak
fdfe9ebb4c cdc: notify when creating or dropping cdc table
When creating a CDC table by updating an existing base table and
enabling CDC, notify about the table creation so subscribers can act on
it.  This is needed in particular for notifying the tablet allocator
when creating a CDC table so that it will allocate tablets for the CDC
table.

Also, when dropping a CDC table, notifying about the dropped table. This
is needed for the tablet allocator to remove the tablet map of the CDC
table.
2025-09-17 14:47:11 +02:00
Michael Litvak
fed1048059 cdc: move cdc table creation to pre_create
When creating a new table with CDC enabled, we create also a CDC log
table by adding the CDC table's mutations in the same operation.

Previously, it works by the CDC log service subscribing to
on_before_create_column_family and adding the CDC table's mutations
there when being notified about a new created table.

The problem is that when we create the tables we also create their
tablet maps in the tablet allocator, and we want to created the two
tables as co-located tables: we allocate a tablet map for the base
table, and the CDC table is co-located with the base table.

This doesn't work well with the previous approach because the
notification that creates the CDC table is the same notification that
the tablet allocator creates the base tablet map, so the two operations
are independent, but really we want the tablet allocator to work on both
tables together, so that we have the base table's schema and tablet map
when we create the CDC table's co-located tablet map.

In order to achieve this, we want to create and add the CDC table's
schema, and only after that notify using before_create_column_families
with a vector that contains both the base table and CDC table. The
tablet allocator will then have all the information it needs to create
the co-located tablet map.

We move the creation of the CDC log table - instead of adding the
table's mutations in on_before_create_column_family, we create the table
schema and add it to the new tables vector in
on_pre_create_column_families, which is called by the migration manager
in do_prepare_new_column_families_announcement. The migration manager
will then create and add all mutations for creating the tables, and
notify about the tables being created together.
2025-09-17 14:47:11 +02:00
Michael Litvak
daf200facb cdc: add is_log_schema helper
In few places we need to check whether a schema represents a CDC log
table, and we do so by checking whether the table's partitioner is the
CDC partitioner.

Extract this logic to a new utility function to reduce code duplication
and allow reuse.
2025-09-17 14:47:11 +02:00
Piotr Dulikowski
762d9ef68f Merge 'cdc: Set tombstone_gc when creating log table' from Dawid Mędrek
Normally, when we create a table, MV, etc., we apply `cf_prop_defs` to the
schema builder via the function `cf_prop_defs::apply_to_builder`. Unfortunately,
that didn't happen when creating CDC log tables, and so we might have missed
some of the properties that would normally be set to some value, even if the
default one.

One particular example of that phenomenon was `tombstone_gc`. For better or
worse, it's not a "standalone property" of a table, but rather part of
`extensions`. [Somewhat related issue: scylladb/scylladb#9722]

That may have and did cause trouble. Consider this scenario:

1. A CDC log table is created.
2. The table does NOT have any value of `tombstone_gc` set.
3. The user edits the table via `ALTER TABLE`. That statement treats the log
   table just like any other one (at least as far as the relevant portion of the
   logic is concerned). Among other things, it uses
   `cf_prop_defs::apply_to_builder`, and as a result, the `tombstone_gc`
   property is set to some value:
   * the default one if the user doesn't specify it in the statement,
   * a custom one if they do.

Why is that a problem?

First of all, it's confusing. When we perform a schema backup and a table uses
CDC, we include an ALTER statement for its corresponding CDC log table (for more
context, see issue scylladb/scylladb#18467 or commit
scylladb/scylladb@f12edbdd95).

There are two consequences for the user here:
1. If the log table had NOT been altered ever since it was created, the
   statement will miss the `tombstone_gc` property as if it couldn't be set for
   it at all. That's confusing!
2. If the log table HAD in fact been altered after its creation, the statement
   will include the `tombstone_gc` property. That's even more confusing (why was
   it not present the first time, but it is now?).

The `tombstone_gc` property should always be set to avoid confusion and
problematic edge cases in tests and to simply be consistent with how other
schema entities work.

The solution we employ is that we always set the property to the default
value. That includes the case when we reattach the log table to the base;
consider the following scenario:

1. Create a table with CDC enabled.
2. Detach the log table by performing `ALTER TABLE ... WITH cdc = {'enabled': false}`.
3. Change the `tombstone_gc` property of the log table.
4. Reattach the log table to the base in the same way as in step 2.

The expected result would be that the new value of `tombstone_gc` would be
preserved after reattaching the log table. However, that's not what will
happen. We decide to stay consistent with how other properties of a log
table behave, and we reset them after every reattachment. We might change that
in the future: see issue scylladb/scylladb#25523.

Two reproducer tests of scylladb/scylladb#25187 are included in the changes.

Backport: The problem is not critical, so it may not be necessary to backport the changes.
That's to be discussed.

Closes scylladb/scylladb#25521

* github.com:scylladb/scylladb:
  cdc: Set tombstone_gc when creating log table
  tombstone_gc: Add overload of get_default_tombstone_gc_mode
  tombstone_gc: Rename get_default_tombstonesonte_gc_mode
2025-09-02 10:20:11 +02:00
Piotr Dulikowski
7ccb50514d Merge 'Introduce view building coordinator' from Michał Jadwiszczak
This patch introduces `view_building_coordinator`, a single entity within whole cluster responsible for building tablet-based views.

The view building coordinator takes slightly different approach than the existing node-local view builder. The whole process is split into smaller view building tasks, one per each tablet replica of the base table.
The coordinator builds one base table at a time and it can choose another when all views of currently processing base table are built.
The tasks are started by setting `STARTED` state and they are executed by node-local view building worker. The tasks are scheduled in a way, that each shard processes only one tablet at a time (multiple tasks can be started for a shard on a node because a table can have multiple views but then all tasks have the same base table and tablet (last_token)). Once the coordinator starts the tasks, it sends `work_on_view_building_tasks` RPC to start the tasks and receive their results.
This RPC is resilient to RPC failure or raft leader change, meaning if one RPC call started a batch of tasks but then failed (for instance the raft leader was changed and caller aborted waiting for the response), next RPC call will attach itself to the already started batch.

The coordinator plugs into handling tablet operations (migration/resize/RF change) and adjusts its tasks accordingly. At the start of each tablet operation, the coordinator aborts necessary view building tasks to prevent https://github.com/scylladb/scylladb/issues/21564. Then, new adjusted tasks are created at the end of the operation.
If the operation fails at any moment, aborted tasks are rollback.

The view building coordinator can also handle staging sstables using process_staging view building tasks. We do this because we don't want to start generating view updates from a staging sstable prematurely, before the writes are directed to the new replica (https://github.com/scylladb/scylladb/issues/19149).

For detailed description check: `docs/dev/view-building-coordinator.md`

Fixes https://github.com/scylladb/scylladb/issues/22288
Fixes https://github.com/scylladb/scylladb/issues/19149
Fixes https://github.com/scylladb/scylladb/issues/21564
Fixes https://github.com/scylladb/scylladb/issues/17603
Fixes https://github.com/scylladb/scylladb/issues/22586
Fixes https://github.com/scylladb/scylladb/issues/18826
Fixes https://github.com/scylladb/scylladb/issues/23930

---

This PR is reimplementation of https://github.com/scylladb/scylladb/pull/21942

Closes scylladb/scylladb#23760

* github.com:scylladb/scylladb:
  test/cluster: add view build status tests
  test/cluster: add view building coordinator tests
  utils/error_injection: allow to abort `injection_handler::wait_for_message()`
  test: adjust existing tests
  utils/error_injection: add injection with `sleep_abortable()`
  db/view/view_builder: ignore `no_such_keyspace` exception
  docs/dev: add view building coordinator documentation
  db/view/view_building_worker: work on `process_staging` tasks
  db/view/view_building_worker: register staging sstable to view building coordinator when needed
  db/view/view_building_worker: discover staging sstables
  db/view/view_building_worker: add method to register staging sstable
  db/view/view_update_generator: add method to process staging sstables instantly
  db/view/view_update_generator: extract generating updates from staging sstables to a method
  db/view/view_update_generator: ignore tablet-based sstables
  db/view/view_building_coordinator: update view build status on node join/left
  db/view/view_building_coordinator: handle tablet operations
  db/view: add view building task mutation builder
  service/topology_coordinator: run view building coordinator
  db/view: introduce `view_building_coordinator`
  db/view/view_building_worker: update built views locally
  db/view: introduce `view_building_worker`
  db/view: extract common view building functionalities
  db/view: prepare to create abstract `view_consumer`
  message/messaging_service: add `work_on_view_building_tasks` RPC
  service/topology_coordinator: make `term_changed_error` public
  db/schema_tables: create/cleanup tasks when an index is created/dropped
  service/migration_manager: cleanup view building state on drop keyspace
  service/migration_manager: cleanup view building state on drop view
  service/migration_manager: create view building tasks on create view
  test/boost: enable proxy remote in some tests
  service/migration_manager: pass `storage_proxy` to `prepare_keyspace_drop_announcement()`
  service/migration_manager: coroutinize `prepare_new_view_announcement()`
  service/storage_proxy: expose references to `system_keyspace` and `view_building_state_machine`
  service: reload `view_building_state_machine` on group0 apply()
  service/vb_coordinator: add currently processing base
  db/system_keyspace: move `get_scylla_local_mutation()` up
  db/system_keyspace: add `view_building_tasks` table
  db/view: add view_building_state and views_state
  db/system_keyspace: add method to get view build status map
  db/view: extract `system.view_build_status_v2` cql statements to system_keyspace
  db/system_keyspace: move `internal_system_query_state()` function earlier
  db/view: ignore tablet-based views in `view_builder`
  gms/feature_service: add VIEW_BUILDING_COORDINATOR feature
2025-08-29 17:28:44 +02:00
Dawid Mędrek
646f8bc4cd cdc: Set tombstone_gc when creating log table
Normally, when we create a table, MV, etc., we apply `cf_prop_defs` to the
schema builder via the function `cf_prop_defs::apply_to_builder`. Unfortunately,
that didn't happen when creating CDC log tables, and so we might have missed
some of the properties that would normally be set to some value, even if the
default one.

One particular example of that phenomenon was `tombstone_gc`. For better or
worse, it's not a "standalone property" of a table, but rather part of
`extensions`. [Somewhat related issue: scylladb/scylladb#9722]

That may have and did cause trouble. Consider this scenario:

1. A CDC log table is created.
2. The table does NOT have any value of `tombstone_gc` set.
3. The user edits the table via `ALTER TABLE`. That statement treats the log
   table just like any other one (at least as far as the relevant portion of the
   logic is concerned). Among other things, it uses
   `cf_prop_defs::apply_to_builder`, and as a result, the `tombstone_gc`
   property is set to some value:
   * the default one if the user doesn't specify it in the statement,
   * a custom one if they do.

Why is that a problem?

First of all, it's confusing. When we perform a schema backup and a table uses
CDC, we include an ALTER statement for its corresponding CDC log table (for more
context, see issue scylladb/scylladb#18467 or commit
scylladb/scylladb@f12edbdd95).

There are two consequences for the user here:
1. If the log table had NOT been altered ever since it was created, the
   statement will miss the `tombstone_gc` property as if it couldn't be set for
   it at all. That's confusing!
2. If the log table HAD in fact been altered after its creation, the statement
   will include the `tombstone_gc` property. That's even more confusing (why was
   it not present the first time, but it is now?).

The `tombstone_gc` property should always be set to avoid confusion and
problematic edge cases in tests and to simply be consistent with how other
schema entities work.

The solution we employ is that we always set the property to the default
value. That includes the case when we reattach the log table to the base;
consider the following scenario:

1. Create a table with CDC enabled.
2. Detach the log table by performing `ALTER TABLE ... WITH cdc = {'enabled': false}`.
3. Change the `tombstone_gc` property of the log table.
4. Reattach the log table to the base in the same way as in step 2.

The expected result would be that the new value of `tombstone_gc` would be
preserved after reattaching the log table. However, that's not what will
happen. We decide to stay consistent with how other properties of a log
table behave, and we reset them after every reattachment. We might change that
in the future: see issue scylladb/scylladb#25523.

Two reproducer tests of scylladb/scylladb#25187 are included in the changes.

Fixes scylladb/scylladb#25187
2025-08-27 13:18:41 +02:00
Michał Jadwiszczak
6e3e287a39 db/schema_tables: create/cleanup tasks when an index is created/dropped
Similarly as in previous commits, create view building tasks when an
index is created and cleanup view building status when it's dropped.
2025-08-27 08:55:47 +02:00
Dawid Pawlik
a27eef9f18 cdc, vector_index: provide minimal option setup for Vector Search
Ensure that the CDC used by Vector Search has at least 24h TTL
and delta mode is set to 'full' or postimage is enabled.

This setup is required by the Vector Store to work as intended.
The TTL of at least 24h is a rough estimate of the maximal time
needed for the full scan conducted by Vector Store to finish.
The delta mode set to 'full' or postimage enabled is needed
to read the values of vectors being written to the table,
so Vector Store can save them in the desired external index.

As the default we set TTL = 24h, delta = 'full', postimage = false.
Full delta is preffered option to log the vector values as it is less
costly and does not require additional read on write.
2025-08-20 17:20:20 +02:00
Dawid Pawlik
af2a544395 cdc: enable CDC log when vector index is created
Enable CDC log table when creating an index on vector column
using 'vector_index' custom index class.
2025-08-20 12:38:52 +02:00
Michael Litvak
86dfa6324f test: cdc: add test_cdc_with_alter
Add a test that tests adding and dropping a column to a table with CDC
enabled while writing to it.
2025-07-17 17:16:17 +02:00
Michael Litvak
b336f282ae cdc: throw error if column doesn't exist
in the CDC log transformer, when creating a CDC mutation based on some
base table mutation, for each value of a base column we set the value in
the CDC column with the same name.

When looking up the column in the CDC schema by name, we may get a null
pointer if a column by that name is not found. This shouldn't happen
normally because the base schema and CDC schema should be compatible,
and for each base column there should be a CDC column with the same
name.

However, there are scenarios where the base schema and CDC schema are
incompatible for a short period of time when they are being altered.
When a base column is being added or dropped, we could get a base
mutation with this column set, and then the CDC transformer picks up the
latest CDC schema which doesn't have this column.

If such thing happens, we fix the code to throw an exception instead of
crashing on null pointer dereference. Currently we don't have a safer
approach to handle this, but this might be changed in the future. The
other alternative is dropping that data silently which we prefer not to
do.

Throwing an error is acceptable because this scenario most likely
indicates this behavior by the user:
* The user adds a new column, and start writing values to the column
  before the ALTER is complete. or,
* The user drops a column, and continues writing values to the column
  while it's being dropped.

Both cases might as well fail with an error because the column is not
found in the base table.

Fixes scylladb/scylladb#24952
2025-07-17 17:16:17 +02:00
Benny Halevy
3feb759943 everywhere: use utils::chunked_vector for list of mutations
Currently, we use std::vector<*mutation> to keep
a list of mutations for processing.
This can lead to large allocation, e.g. when the vector
size is a function of the number of tables.

Use a chunked vector instead to prevent oversized allocations.

`perf-simple-query --smp 1` results obtained for fixed 400MHz frequency
and PGO disabled:

Before (read path):
```
enable-cache=1
Running test with config: {partitions=10000, concurrency=100, mode=read, query_single_key=no, counters=no}
Disabling auto compaction
Creating 10000 partitions...

89055.97 tps ( 66.1 allocs/op,   0.0 logallocs/op,  14.2 tasks/op,   39417 insns/op,   18003 cycles/op,        0 errors)
103372.72 tps ( 66.1 allocs/op,   0.0 logallocs/op,  14.2 tasks/op,   39380 insns/op,   17300 cycles/op,        0 errors)
98942.27 tps ( 66.1 allocs/op,   0.0 logallocs/op,  14.2 tasks/op,   39413 insns/op,   17336 cycles/op,        0 errors)
103752.93 tps ( 66.1 allocs/op,   0.0 logallocs/op,  14.2 tasks/op,   39407 insns/op,   17252 cycles/op,        0 errors)
102516.77 tps ( 66.1 allocs/op,   0.0 logallocs/op,  14.2 tasks/op,   39403 insns/op,   17288 cycles/op,        0 errors)
throughput:
	mean=   99528.13 standard-deviation=6155.71
	median= 102516.77 median-absolute-deviation=3844.59
	maximum=103752.93 minimum=89055.97
instructions_per_op:
	mean=   39403.99 standard-deviation=14.25
	median= 39406.75 median-absolute-deviation=9.30
	maximum=39416.63 minimum=39380.39
cpu_cycles_per_op:
	mean=   17435.81 standard-deviation=318.24
	median= 17300.40 median-absolute-deviation=147.59
	maximum=18002.53 minimum=17251.75
```

After (read path)
```
enable-cache=1
Running test with config: {partitions=10000, concurrency=100, mode=read, query_single_key=no, counters=no}
Disabling auto compaction
Creating 10000 partitions...
59755.04 tps ( 66.2 allocs/op,   0.0 logallocs/op,  14.2 tasks/op,   39466 insns/op,   22834 cycles/op,        0 errors)
71854.16 tps ( 66.1 allocs/op,   0.0 logallocs/op,  14.2 tasks/op,   39417 insns/op,   17883 cycles/op,        0 errors)
82149.45 tps ( 66.1 allocs/op,   0.0 logallocs/op,  14.2 tasks/op,   39411 insns/op,   17409 cycles/op,        0 errors)
49640.04 tps ( 66.1 allocs/op,   0.0 logallocs/op,  14.3 tasks/op,   39474 insns/op,   19975 cycles/op,        0 errors)
54963.22 tps ( 66.1 allocs/op,   0.0 logallocs/op,  14.3 tasks/op,   39474 insns/op,   18235 cycles/op,        0 errors)
throughput:
	mean=   63672.38 standard-deviation=13195.12
	median= 59755.04 median-absolute-deviation=8709.16
	maximum=82149.45 minimum=49640.04
instructions_per_op:
	mean=   39448.38 standard-deviation=31.60
	median= 39466.17 median-absolute-deviation=25.75
	maximum=39474.12 minimum=39411.42
cpu_cycles_per_op:
	mean=   19267.01 standard-deviation=2217.03
	median= 18234.80 median-absolute-deviation=1384.25
	maximum=22834.26 minimum=17408.67
```

`perf-simple-query --smp 1 --write` results obtained for fixed 400MHz frequency
and PGO disabled:

Before (write path):
```
enable-cache=1
Running test with config: {partitions=10000, concurrency=100, mode=write, query_single_key=no, counters=no}
Disabling auto compaction
63736.96 tps ( 59.4 allocs/op,  16.4 logallocs/op,  14.3 tasks/op,   49667 insns/op,   19924 cycles/op,        0 errors)
64109.41 tps ( 59.3 allocs/op,  16.0 logallocs/op,  14.3 tasks/op,   49992 insns/op,   20084 cycles/op,        0 errors)
56950.47 tps ( 59.3 allocs/op,  16.0 logallocs/op,  14.3 tasks/op,   50005 insns/op,   20501 cycles/op,        0 errors)
44858.42 tps ( 59.3 allocs/op,  16.0 logallocs/op,  14.3 tasks/op,   50014 insns/op,   21947 cycles/op,        0 errors)
28592.87 tps ( 59.3 allocs/op,  16.0 logallocs/op,  14.3 tasks/op,   50027 insns/op,   27659 cycles/op,        0 errors)
throughput:
	mean=   51649.63 standard-deviation=15059.74
	median= 56950.47 median-absolute-deviation=12087.33
	maximum=64109.41 minimum=28592.87
instructions_per_op:
	mean=   49941.18 standard-deviation=153.76
	median= 50005.24 median-absolute-deviation=73.01
	maximum=50027.07 minimum=49667.05
cpu_cycles_per_op:
	mean=   22023.01 standard-deviation=3249.92
	median= 20500.74 median-absolute-deviation=1938.76
	maximum=27658.75 minimum=19924.32
```

After (write path)
```
enable-cache=1
Running test with config: {partitions=10000, concurrency=100, mode=write, query_single_key=no, counters=no}
Disabling auto compaction
53395.93 tps ( 59.4 allocs/op,  16.5 logallocs/op,  14.3 tasks/op,   50326 insns/op,   21252 cycles/op,        0 errors)
46527.83 tps ( 59.3 allocs/op,  16.0 logallocs/op,  14.3 tasks/op,   50704 insns/op,   21555 cycles/op,        0 errors)
55846.30 tps ( 59.3 allocs/op,  16.0 logallocs/op,  14.3 tasks/op,   50731 insns/op,   21060 cycles/op,        0 errors)
55669.30 tps ( 59.3 allocs/op,  16.0 logallocs/op,  14.3 tasks/op,   50735 insns/op,   21521 cycles/op,        0 errors)
52130.17 tps ( 59.3 allocs/op,  16.0 logallocs/op,  14.3 tasks/op,   50757 insns/op,   21334 cycles/op,        0 errors)
throughput:
	mean=   52713.91 standard-deviation=3795.38
	median= 53395.93 median-absolute-deviation=2955.40
	maximum=55846.30 minimum=46527.83
instructions_per_op:
	mean=   50650.57 standard-deviation=182.46
	median= 50731.38 median-absolute-deviation=84.09
	maximum=50756.62 minimum=50325.87
cpu_cycles_per_op:
	mean=   21344.42 standard-deviation=202.86
	median= 21334.00 median-absolute-deviation=176.37
	maximum=21554.61 minimum=21060.24
```

Fixes #24815

Improvement for rare corner cases. No backport required

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

Closes scylladb/scylladb#24919
2025-07-13 19:13:11 +03:00
Amnon Heiman
cf50c71ef5 cdc/log.cc: label metrics with basic_level and cdc
The following metrics will be marked with basic_level label:
scylla_cdc_operations_failed
scylla_cdc_operations_total

All metrics are labeld with the __cdc label.

Signed-off-by: Amnon Heiman <amnon@scylladb.com>
2025-03-03 16:58:38 +02:00
Kefu Chai
e218a62a7a cdc,index: replace boost::ends_with() with .ends_with()
since C++20, std::string and std::string_view started providing
`ends_with()` member function, the same applies to `seastar::sstring`,
so there is no need to use `boost::ends_with()` anymore.

in this change, we switch from `boost::ends_with()` to the member
functions variant to

- improve the readability
- reduce the header dependency

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>

Closes scylladb/scylladb#22502
2025-01-29 11:52:55 +03:00
Avi Kivity
f3eade2f62 treewide: relicense to ScyllaDB-Source-Available-1.0
Drop the AGPL license in favor of a source-available license.
See the blog post [1] for details.

[1] https://www.scylladb.com/2024/12/18/why-were-moving-to-a-source-available-license/
2024-12-18 17:45:13 +02:00
Nadav Har'El
e639434a89 change remaining sstring_view to std::string_view
Our "sstring_view" is an historic alias for the standard std::string_view.
The patch changes the last remaining random uses of this old alias across
our source directory to the standard type name.

After this patch, there are no more uses of the "sstring_view" alias.
It will be removed in the following patch.

Refs #4062.

Signed-off-by: Nadav Har'El <nyh@scylladb.com>
2024-11-18 16:48:57 +02:00
Kefu Chai
3e84d43f93 treewide: use seastar::format() or fmt::format() explicitly
before this change, we rely on `using namespace seastar` to use
`seastar::format()` without qualifying the `format()` with its
namespace. this works fine until we changed the parameter type
of format string `seastar::format()` from `const char*` to
`fmt::format_string<...>`. this change practically invited
`seastar::format()` to the club of `std::format()` and `fmt::format()`,
where all members accept a templated parameter as its `fmt`
parameter. and `seastar::format()` is not the best candidate anymore.
despite that argument-dependent lookup (ADT for short) favors the
function which is in the same namespace as its parameter, but
`using namespace` makes `seastar::format()` more competitive,
so both `std::format()` and `seastar::format()` are considered
as the condidates.

that is what is happening scylladb in quite a few caller sites of
`format()`, hence ADT is not able to tell which function the winner
in the name lookup:

```
/__w/scylladb/scylladb/mutation/mutation_fragment_stream_validator.cc:265:12: error: call to 'format' is ambiguous
  265 |     return format("{} ({}.{} {})", _name_view, s.ks_name(), s.cf_name(), s.id());
      |            ^~~~~~
/usr/bin/../lib/gcc/x86_64-redhat-linux/14/../../../../include/c++/14/format:4290:5: note: candidate function [with _Args = <const std::basic_string_view<char> &, const seastar::basic_sstring<char, unsigned int, 15> &, const seastar::basic_sstring<char, unsigned int, 15> &, const utils::tagged_uuid<table_id_tag> &>]
 4290 |     format(format_string<_Args...> __fmt, _Args&&... __args)
      |     ^
/__w/scylladb/scylladb/seastar/include/seastar/core/print.hh:143:1: note: candidate function [with A = <const std::basic_string_view<char> &, const seastar::basic_sstring<char, unsigned int, 15> &, const seastar::basic_sstring<char, unsigned int, 15> &, const utils::tagged_uuid<table_id_tag> &>]
  143 | format(fmt::format_string<A...> fmt, A&&... a) {
      | ^
```

in this change, we

change all `format()` to either `fmt::format()` or `seastar::format()`
with following rules:
- if the caller expects an `sstring` or `std::string_view`, change to
  `seastar::format()`
- if the caller expects an `std::string`, change to `fmt::format()`.
  because, `sstring::operator std::basic_string` would incur a deep
  copy.

we will need another change to enable scylladb to compile with the
latest seastar. namely, to pass the format string as a templated
parameter down to helper functions which format their parameters.
to miminize the scope of this change, let's include that change when
bumping up the seastar submodule. as that change will depend on
the seastar change.

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
2024-09-11 23:21:40 +03:00
Avi Kivity
aa1270a00c treewide: change assert() to SCYLLA_ASSERT()
assert() is traditionally disabled in release builds, but not in
scylladb. This hasn't caused problems so far, but the latest abseil
release includes a commit [1] that causes a 1000 insn/op regression when
NDEBUG is not defined.

Clearly, we must move towards a build system where NDEBUG is defined in
release builds. But we can't just define it blindly without vetting
all the assert() calls, as some were written with the expectation that
they are enabled in release mode.

To solve the conundrum, change all assert() calls to a new SCYLLA_ASSERT()
macro in utils/assert.hh. This macro is always defined and is not conditional
on NDEBUG, so we can later (after vetting Seastar) enable NDEBUG in release
mode.

[1] 66ef711d68

Closes scylladb/scylladb#20006
2024-08-05 08:23:35 +03:00
Kefu Chai
ad649be1bf treewide: drop thrift support
thrift support was deprecated since ScyllaDB 5.2

> Thrift API - legacy ScyllaDB (and Apache Cassandra) API is
> deprecated and will be removed in followup release. Thrift has
> been disabled by default.

so let's drop it. in this change,

* thrift protocol support is dropped
* all references to thrift support in document are dropped
* the "thrift_version" column in system.local table is
  preserved for backward compatibility, as we could load
  from an existing system.local table which still contains
  this clolumn, so we need to write this column as well.
* "/storage_service/rpc_server" is only preserved for
  backward compatibility with java-based nodetool.
* `rpc_port` and `start_rpc` options are preserved, but
  they are marked as "Unused". so that the new release
  of scylladb can consume existing scylla.yaml configurations
  which might contain these settings. by making them
  deprecated, user will be able get warned, and update
  their configurations before we actually remove them
  in the next major release.

Fixes #3811
Fixes #18416
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
2024-06-07 06:44:59 +08:00
Kefu Chai
af2553e8bc cdc: add formatter for cdc::image_mode and cdc::delta_mode
before this change, we rely on the default-generated fmt::formatter
created from operator<<, but fmt v10 dropped the default-generated
formatter.

in this change, we define formatters for
cdc::image_mode and cdc::delta_mode, and drop their operator<<:s.

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>

Closes scylladb/scylladb#17381
2024-02-18 19:21:53 +02:00