If the view building coordinator is running, adjust view_building_tasks
in case of tablet operations.
The mutations are generated in the same batch as tablet mutations.
At the start of tablet migration/resize/RF change, started
view building tasks are aborted (by setting ABORTED state) if needed.
Then, new adjusted tasks are created in group0 batch which ends the
tablet operation and aborted tasks are removed from the table.
In case the tablet operation fails or is revoked, aborted view building
tasks are rollback by creating new copies of them and aborted ones are
deleted from the table.
View building tasks are not aborted/changed during tablet repair,
because in this case, even if vb task is started, a staging sstable will
be generated.
The coordinator is responsible for building tablet-based views.
It schedules tasks for `view_building_worker` and updates views'
statuses.
The tasks are scheduled in a way that one shard is processing only one
tablet at most (there may be multiple tasks since a base table may have
multiple views).
Support for tablet operations will be added in next commits.
Because `system.built_views` is a node-local table, we cannot mark a
view as built directly from the view building coordinator.
Instead, view building worker looks at data from
`syste.view_build_status_v2` and updates `built_views` table
accordingly.
The worker is responsible for building tablet-based views by
executing tasks scheduled by the view building coordinator.
It observes view building state machine and wait on the machine's
conditional variable (so the worker is woken up when group0 state is
applied).
The tasks are executed in batches, all tasks in one batch need to have
the same: type, base_id, table_id. One shard can only execute one batch
at a time (at least for now, in the future we might want to change
that).
That worker keeps track of finished and failed tasks in its local state.
The state is cleared when `view_building_state::currently_processed_base_table`
is changed.
Extract common methods of view builder consumer to an abstract class
and `flush_base()` and `make_partition_slice()` functions,
so they can be used in view builder (vnode-based views) and view
building consumer (tablet-based views; introduced in the next commit).
In next commit, I'm going to introduce `view_building_worker::consumer`,
with very similar functionalities to `view_builder::consumer` but it'll
only consume range of one tablet per execution.
Since most functions are very similar, I'll create abstract
`view_consumer` which will be base for both of the consumers.
In order to make the transition more readable, this commit prepares
the `view_builder::consumer` by making some functions virtual and next
commit will extract part of functions to the abstract class.
The RPC will be used by view building coordinator to attach to and wait
for tasks performed by view building worker (introduced in later
commit).
The RPC gets vector of tasks' ids and returns vector of
`view_task_result`s.
i-th task result reffers to i-th task id.
The state may be also reloaded on `topology_change` or `mixed_change`
because topology coordinator may change view building tasks during
tablet operations.
The view building coordinator will be building all views
of one base table at a time.
Select first available base table as currently processing base
and save this information to `system.scylla_local`.
`view_building_state` holds mapping of `view_building_task`s for
tablet-based views. The structure is a memory representation of data
stored in group0 tables.
`views_state` holds information about tablet-based views and their
build status.
Until now, all changes to `system.view_build_status_v2` were made from
view.cc and the file contained all of the helper methods.
This commit introduces a `build_status` enum class to avoid using
hardcoded strings and extracts the helper methods to `system_keyspace`
class, so they can be later used by the view building coordinator.
This series adds support for a DynamoDB-compatible Write Capacity Unit (WCU) calculation in Alternator by introducing an optional forced read-before-write mechanism.
Alternator's model differs from DynamoDB, and as a result, some write operations may report lower WCU usage compared to what DynamoDB would report. While this is acceptable in many cases, there are scenarios where users may require accurate WCU reporting that aligns more closely with DynamoDB's behavior.
To address this, a new configuration option, alternator_force_read_before_write, is introduced. When enabled, Alternator will perform a read before executing PutItem, UpdateItem, and DeleteItem operations. This allows it to take the existing item size into account when computing the WCU. BatchWriteItem support is also extended to use this mechanism. Because BatchWriteItem does not support returning old items directly, several internal changes were made to support reading previous item sizes with minimal overhead. Reads are performed at consistency level LOCAL_ONE for efficiency, and the WCU calculation is now done in multiple stages to accurately account for item size differences.
In addition to the implementation changes, test coverage was added to validate the new behavior. These tests confirm that WCU is calculated based on the larger of the old and new items when read-before-write is active, including for BatchWriteItem.
This feature comes with performance overhead and is therefore disabled by default. It can be enabled at runtime via the system.config table and should be used only when precise WCU tracking is necessary.
**New feature, no need to backport**
Closesscylladb/scylladb#24436
* github.com:scylladb/scylladb:
alternator/test_returnconsumedcapacity.py: Test forced read before write
alternator/executor.cc: DynamoDB WCU calculation in BatchWriteItem using read-before-write
executor.cc: get_previous_item with consistency level
executor: Extend API of put_or_delete_item
alternator/executor.cc: Accurate WCU for put, update, delete
config: add alternator_force_read_before_write
Before these changes, the logs in hinted handoff often didn't provide
crucial information like the identifier of the node that hints were
being sent to. Also, some of the logs were misleading and referred to
other places in the code than the one where an exception or some other
situation really occurred.
We modify those logs, extending them by more valuable information
and fixing existing issues. What's more, all of the logs in
`hint_endpoint_manager` and `hint_sender` follow a consistent format
now:
```
<class_name>[<destination host ID>]:<function_name>: <message>
```
This way, we should always have AT LEAST the basic information.
Fixesscylladb/scylladb#25466
Backport:
There is no risk in backporting these changes. They only have
impact on the logs. On the other hand, they might prove helpful
when debugging an issue in hinted handoff.
Closesscylladb/scylladb#25470
* github.com:scylladb/scylladb:
db/hints: Add new logs
db/hints: Adjust log levels
db/hints: Improve logs
Some of the logs could be clogging Scylla's logs, so we demote their
level to a lower one.
On the other hand, some of the logs would most likely not do that,
and they could be useful when debugging -- we promote them to debug
level.
Before these changes, the logs in hinted handoff often didn't provide
crucial information like the identifier of the node that hints were
being sent to. Also, some of the logs were misleading and referred to
other places in the code than the one where an exception or some other
situation really occurred.
We modify those logs, extending them by more valuable information
and fixing existing issues. What's more, all of the logs in
`hint_endpoint_manager` and `hint_sender` follow a consistent format
now:
```
<class_name>[<destination host ID>]:<function_name>: <message>
```
This way, we should always have AT LEAST the basic information.
Enable runtime updates of vector_store_uri configuration without
requiring server restart.
This allows to dynamically enable, disable, or switch the vector search node endpoint on the fly.
Obtaining the gc-before time, or the min-live timestamps (with the
expiry threshold) is not always trivial, so defer it until we know it is
needed. Not all reads will attempt to garbage-collect tombstones, these
reads can now avoid this work.
The downside is that the partition key has to be copied and stored, as
it is necessary for obtaining the min-live timestamp later.
In commit 44a1daf we added the ability to read Scylla system tables with Alternator. This feature is useful, among other things, in tests that want to read Scylla's configuration through the system table system.config. But tests often want to modify system.config, e.g., to temporarily reduce some threshold to make tests shorter. Until now, this was not possible
This series add supports for writing to system tables through Alternator, and examples of tests using this capability (and utility functions to make it easy).
Because the ability to write to system tables may have non-obvious security consequences, it is turned off by default and needs to be enabled with a new configuration option "alternator_allow_system_table_write"
No backports are necessary - this feature is only intended for tests. We may later decide to backport if we want to backport new tests, but I think the probability we'll want to do this is low.
Fixes#12348Closesscylladb/scylladb#19147
* github.com:scylladb/scylladb:
test/alternator: utility functions for changing configuration
alternator: add optional support for writing to system table
test/alternator: reduce duplicated code
In commit 44a1daf we added the ability to read system tables through
the DynamoDB API (actually, the Scan and Query requests only).
This ability is useful for tests, and can also be useful to users who
want to read information that is only available through system tables.
This patch adds support also for *writing* into system tables. This will
be useful for Alternator tests, were we want to temporarily change
some live-updatable configuration option - and so far haven't been
able to do that like we did do in some cql-pytest tests.
For reasons explained in issue #23218, only superuser roles are allowed to
write to system tables - it is not enough for the role to be granted
MODIFY permissions on the system table or on ALL KEYSPACES. Moreover,
the ability to modify system tables carries special risks, so this
patch only allows writes to the system tables if a new configuration
option "alternator_allow_system_table_write" turned on. This option is
turned off by default.
This patch also includes a test for this new configuration-writing
capability. The test scripts test/alternator/run and test.py now
run Scylla with alternator_allow_system_table_write turned on, but
the new test can also run without this option, and will be skipped
in that case (to allow running the test suite against some manually-
run instance of Scylla).
Fixes: #12348
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
This pull request is an addition of ANN OF queries.
The patch contains:
- CQL syntax for ORDER BY `vector_column_name` ANN OF `vector_literal` clause of SELECT statements.
- implementation of external ANN queries (using vector-store service)
- tests
Example syntax:
```
SELECT comment
FROM cycling.comments_vs
ORDER BY comment_vector ANN OF [0.1, 0.15, 0.3, 0.12, 0.05]
LIMIT 3;
```
Limit can be between 1 and 1000 - same as for Cassandra.
Co-authored-by: @janpiotrlakomy @smoczy123
Fixes: VECTOR-48
Fixes: VECTOR-46
Closesscylladb/scylladb#24444
* github.com:scylladb/scylladb:
cql3/statements: implement external `ANN OF` queries
vector_store_client: implement ann_error_visitor
test/cqlpy: check ANN queries disallow filtering properly
cassandra_tests: translate vector_invalid_query_test
cassandra_tests: copy vector_invalid_query_test from Cassandra
vector_index: make parameter names case insensitive
cql3/statements: add `ANN OF` queries support to select statements
cql/Cql.g: extend the grammar to allow for `ANN OF` queries
cql3/raw: add ANN ordering to the raw statement layer
This patch introduces a new configuration parameter,
`alternator_force_read_before_write`, which forces Alternator to perform
a read-before-write on all write operations (`PutItem`, `UpdateItem`, and
`DeleteItem`), even when not strictly required.
Enabling this option ensures abetter DynamoDB compatibility in WCU
calculation. by accounting for the size of the existing item, as done
in DynamoDB.
This option introduces performance overhead and should be used with care.
The parameter is runtime-configurable and can be toggled via CQL:
UPDATE system.config SET value = 'true' WHERE name = 'alternator_force_read_before_write';
The following steps are performed in sequence as part of the
Raft-based recovery procedure:
- set `recovery_leader` to the host ID of the recovery leader in
`scylla.yaml` on all live nodes,
- send the `SIGHUP` signal to all Scylla processes to reload the config,
- perform a rolling restart (with the recovery leader being restarted
first).
These steps are not intuitive and more complicated than they could be.
In this PR, we simplify these steps. From now on, we will be able to
simply set `recovery_leader` on each node just before restarting it.
Apart from making necessary changes in the code, we also update all
tests of the Raft-based recovery procedure and the user-facing
documentation.
Fixesscylladb/scylladb#25015
The Raft-based procedure was added in 2025.2. This PR makes the
procedure simpler and less error-prone, so it should be backported
to 2025.2 and 2025.3.
Closesscylladb/scylladb#25032
* github.com:scylladb/scylladb:
docs: document the option to set recovery_leader later
test: delay setting recovery_leader in the recovery procedure tests
gossip: add recovery_leader to gossip_digest_syn
db: system_keyspace: peers_table_read_fixup: remove rows with null host_id
db/config, gms/gossiper: change recovery_leader to UUID
db/config, utils: allow using UUID as a config option
Add parsing of `ANN OF` queries to the `select_statement` and
`indexed_table_select_statement` classes.
Add a placeholder for the implementation of external ANN queries.
Rename `should_create_view` to `view_should_exist` as it is used
not only to check if the view should be created but also if
the view has been created.
Co-authored-by: Dawid Pawlik <dawid.pawlik@scylladb.com>
This commits introduces an config option 'tablet_load_stats_refresh_interval_in_seconds'
that allows overriding the default value without using error injection.
Fixesscylladb/scylladb#24641Closesscylladb/scylladb#24746
This PR implements solution proposed in scylladb/scylladb#24481
Instead of terminating connections immediately, the shutdown now proceeds in two stages: first closing the receive (input) side to stop new requests, then waiting for all active requests to complete before fully closing the connections.
The updated shutdown process is as follows:
1. Initial Shutdown Phase
* Close the accept gate to block new incoming connections.
* Abort all accept() calls.
* For all active connections:
* Close only the input side of the connection to prevent new requests.
* Keep the output side open to allow responses to be sent.
2. Drain Phase
* Wait for all in-progress requests to either complete or fail.
3. Final Shutdown Phase
* Fully close all connections.
Fixesscylladb/scylladb#24481Closesscylladb/scylladb#24499
* https://github.com/scylladb/scylladb:
test: Set `request_timeout_on_shutdown_in_seconds` to `request_timeout_in_ms`, decrease request timeout.
generic_server: Two-step connection shutdown.
transport: consmetic change, remove extra blanks.
transport: Handle sleep aborted exception in sleep_until_timeout_passes
generic_server: replace empty destructor with `= default`
generic_server: refactor connection::shutdown to use `shutdown_input` and `shutdown_output`
generic_server: add `shutdown_input` and `shutdown_output` functions to `connection` class.
test: Add test for query execution during CQL server shutdown
We're providing additional information in error messages when throwing
an exception related to data corruption: when a segment is truncated
and when it's content is invalid. That might prove helpful when debugging.
Closesscylladb/scylladb#25190
std::enable_if is obsolete and was replaced with concepts
and constraint.
Replace the std::is_fundamental_v enable_if constraint with
std::integral. The latter is more accurate - std::ntoh()
is not defined for floats, for example. In any case, we only
read integrals in commitlog.
Closesscylladb/scylladb#25226
This PR enables **LWT (Lightweight Transactions)** support for tablet-based tables by leveraging **colocated tables**.
Currently, storing Paxos state in system tables causes two major issues:
* **Loss of Paxos state during tablet migration or base table rebuilds**
* When a tablet is migrated or the base table is rebuilt, system tables don't retain Paxos state.
* This breaks LWT correctness in certain scenarios.
* Failing test cases demonstrating this:
* test_lwt_state_is_preserved_on_tablet_migration
* test_lwt_state_is_preserved_on_rebuild
* **Shard misalignment and performance overhead**
* Tablets may be placed on arbitrary shards by the tablet balancer.
* Accessing Paxos state in system tables could require a shard jump, degrading performance.
We move Paxos state into a dedicated Paxos table, colocated with the base table:
* Each base table gets its own Paxos state table.
* This table is lazily created on the first LWT operation.
* Its tablets are colocated with those of the base table, ensuring:
* Co-migration during tablet movement
* Co-rebuilding with the base table
* Shard alignment for local access to Paxos state
Some reasoning for why this is sufficient to preserve LWT correctness is discussed in [2].
This PR addresses two issues from the "Why doesn't it work for tablets" section in [1]:
* Tablet migration vs LWT correctness
* Paxos table sharding
Other issues ("bounce to shard" and "locking for intranode_migration") have already been resolved in previous PRs.
References
[1] - [LWT over tablets design](https://docs.google.com/document/d/1CPm0N9XFUcZ8zILpTkfP5O4EtlwGsXg_TU4-1m7dTuM/edit?tab=t.0#heading=h.goufx7gx24yu)
[2] - [LWT: Paxos state and tablet balancer](https://docs.google.com/document/d/1-xubDo612GGgguc0khCj5ukmMGgLGCLWLIeG6GtHTY4/edit?tab=t.0)
[3] - [Colocated tables PR](https://github.com/scylladb/scylladb/pull/22906#issuecomment-3027123886)
[4] - [Possible LWT consistency violations after a topology change](https://github.com/scylladb/scylladb/issues/5251)
Backport: not needed because this is a new feature.
Closesscylladb/scylladb#24819
* github.com:scylladb/scylladb:
create_keyspace: fix warning for tablets
docs: fix lwt.rst
docs: fix tablets.rst
alternator: enable LWT
random_failures: enable execute_lwt_transaction
test_tablets_lwt: add test_paxos_state_table_permissions
test_tablets_lwt: add test_lwt_for_tablets_is_not_supported_without_raft
test_tablets_lwt: test timeout creating paxos state table
test_tablets_lwt: add test_lwt_concurrent_base_table_recreation
test_tablets_lwt: add test_lwt_state_is_preserved_on_rebuild
test_tablets_lwt: migrate test_lwt_support_with_tablets
test_tablets_lwt: add test_lwt_state_is_preserved_on_tablet_migration
test_tablets_lwt: add simple test for LWT
check_internal_table_permissions: handle Paxos state tables
client_state: extract check_internal_table_permissions
paxos_store: handle base table removal
database: get_base_table_for_tablet_colocation: handle paxos state table
paxos_state: use node_local_only mode to access paxos state
query_options: add node_local_only mode
storage_proxy: handle node_local_only in query
storage_proxy: handle node_local_only in mutate
storage_proxy: introduce node_local_only flag
abstract_replication_strategy: remove unused using
storage_proxy: add coordinator_mutate_options
storage_proxy: rename create_write_response_handler -> make_write_response_handler
storage_proxy: simplify mutate_prepare
paxos_state: lazily create paxos state table
migration_manager: add timeout to start_group0_operation and announce
paxos_store: use non-internal queries
qp: make make_internal_options public
paxos_store: conditional cf_id filter
paxos_store: coroutinize
feature_service: add LWT_WITH_TABLETS feature
paxos_state: inline system_keyspace functions into paxos_store
paxos_state: extract state access functions into paxos_store
When shutting down in `generic_server`, connections are now closed in two steps.
First, only the RX (receive) side is shut down. Then, after all ongoing requests
are completed, or a timeout happened the connections are fully closed.
Fixesscylladb/scylladb#24481
We improve logging in critical functions in hinted handoff
to capture more information about the behavior of the module.
That should help us in debugging sessions.
The logs should only be printed during more important events
and so they should not clog the log files.
Backport: not necessary.
Closesscylladb/scylladb#25031
* github.com:scylladb/scylladb:
db/hints/manager.cc: Add logs for changing host filter
db/hints: Increase log level in critical functions
As requested in #22102, #22103 and #22105 moved the files and fixed other includes and build system.
Moved files:
- clustering_bounds_comparator.hh
- keys.cc
- keys.hh
- clustering_interval_set.hh
- clustering_key_filter.hh
- clustering_ranges_walker.hh
- compound_compat.hh
- compound.hh
- full_position.hh
Fixes: #22102Fixes: #22103Fixes: #22105Closesscylladb/scylladb#25082
We add new logs when the host filter is undergoing a change. It should not
happen very often and so it shouldn't clog the log files. At the same
time, it provides us with useful information when debugging.
We increase the log level in more important functions to capture
more information about the behavior of hints. All of the promoted
logs are printed rarely, so they should not clog the log files, but
at the same time they provide more insight into what has already
happened and what has not.
Currently, `peers_table_read_fixup` removes rows with no `host_id`, but
not with null `host_id`. Null host IDs are known to appear in system
tables, for example in `system.cluster_status` after a failed bootstrap.
We better make sure we handle them properly if they ever appear in
`system.peers`.
This commit guarantees that null UUID cannot belong to
`loaded_endpoints` in `storage_service::join_cluster`, which in
particular ensures that we throw a runtime error when a user sets
`recovery_leader` to null UUID during the recovery procedure. This is
handled by the code verifying that `recovery_leader` belongs to
`loaded_endpoints`.
We change the type of the `recovery_leader` config parameter and
`gossip_config::recovery_leader` from sstring to UUID. `recovery_leader`
is supposed to store host ID, so UUID is a natural choice.
After changing the type to UUID, if the user provides an incorrect UUID,
parsing `recovery_leader` will fail early, but the start-up will
continue. Outside the recovery procedure, `recovery_leader` will then be
ignored. In the recovery procedure, the start-up will fail on:
```
throw std::runtime_error(
"Cannot start - Raft-based topology has been enabled but persistent group 0 ID is not present. "
"If you are trying to run the Raft-based recovery procedure, you must set recovery_leader.");
```
CPU scheduling has been with us since 641aaba12c
(2017), and no one ever disables it. Likely nothing really works without
it.
Make it mandatory and mark the option unused.
Closesscylladb/scylladb#24894
