Introduce an initial and experimental implementation of an alternative log-structured storage engine for key-value tables.
Main flows and components:
* The storage is composed of 32MB files, each file divided to segments of size 128k. We write to them sequentially records that contain a mutation and additional metadata. Records are written to a buffer first and then written to the active segment sequentially in 4k sized blocks.
* The primary index in memory maps keys to their location on disk. It is a B-tree per-table that is ordered by tokens, similar to a memtable.
* On reads we calculate the key and look it up in the primary index, then read the mutation from disk with a single disk IO.
* On writes we write the record to a buffer, wait for it to be written to disk, then update the index with the new location, and free the previous record.
* We track the used space in each segment. When overwriting a record, we increase the free space counter for the segment of the previous record that becomes dead. We store the segments in a histogram by usage.
* The compaction process takes segments with low utilization, reads them and writes the live records to new segments, and frees the old segments.
* Segments are initially "mixed" - we write to the active segment records from all tables and all tablets. The "separator" process rewrites records from mixed segments into new segments that are organized by compaction groups (tablets), and frees the mixed segments. Each write is written to the active segment and to a separator buffer of the compaction group, which is eventually flushed to a new segment in the compaction group.
Currently this mode is experimental and requires an experimental flag to be enabled.
Some things that are not supported yet are strong consistency, tablet migration, tablet split/merge, big mutations, tombstone gc, ttl.
to use, add to config:
```
enable_logstor: true
experimental_features:
- logstor
```
create a table:
```
CREATE TABLE ks.t(pk int PRIMARY KEY, a int, v text) WITH storage_engine = 'logstor';
```
INSERT, SELECT, DELETE work as expected
UPDATE not supported yet
no backport - new feature
Closesscylladb/scylladb#28706
* github.com:scylladb/scylladb:
logstor: trigger separator flush for buffers that hold old segments
docs/dev: add logstor documentation
logstor: recover segments into compaction groups
logstor: range read
logstor: change index to btree by token per table
logstor: move segments to replica::compaction_group
db: update dirty mem limits dynamically
logstor: track memory usage
logstor: logstor stats api
logstor: compaction buffer pool
logstor: separator: flush buffer when full
logstor: hold segment until index updates
logstor: truncate table
logstor: enable/disable compaction per table
logstor: separator buffer pool
test: logstor: add separator and compaction tests
logstor: segment and separator barrier
logstor: separator debt controller
logstor: compaction controller
logstor: recovery: recover mixed segments using separator
logstor: wait for pending reads in compaction
logstor: separator
logstor: compaction groups
logstor: cache files for read
logstor: recovery: initial
logstor: add segment generation
logstor: reserve segments for compaction
logstor: index: buckets
logstor: add buffer header
logstor: add group_id
logstor: record generation
logstor: generation utility
logstor: use RIPEMD-160 for index key
test: add test_logstor.py
api: add logstor compaction trigger endpoint
replica: add logstor to db
schema: add logstor cf property
logstor: initial commit
db: disable tablet balancing with logstor
db: add logstor experimental feature flag
In this series we add support for forwarding strongly consistent CQL requests to suitable replicas, so that clients can issue reads/writes to any node and have the request executed on an appropriate tablet replica (and, for writes, on the Raft leader). We return the same CQL response as what the user would get while sending the request to the correct replica and we perform the same logging/stats updates on the request coordinator as if the coordinator was the appropriate replica.
The core mechanism of forwarding a strongly consistent request is sending an RPC containing the user's cql request frame to the appropriate replica and returning back a ready, serialized `cql_transport::response`. We do this in the CQL server - it is most prepared for handling these types and forwarding a request containing a CQL frame allows us to reuse near-top-level methods for CQL request handling in the new RPC handler (such as the general `process`)
For sending the RPC, the CQL server needs to obtain the information about who should it forward the request to. This requires knowledge about the tablet raft group members and leader. We obtain this information during the execution of a `cql3/strong_consistency` statement, and we return this information back to the CQL server using the generalized `bounce_to_shard` `response_message`, where we now store the information about either a shard, or a specific replica to which we should forward to. Similarly to `bounce_to_shard`, we need to handle this `result_message` in a loop - a replica may move during statement execution, or the Raft leader can change. We also use it for forwarding strongly consistent writes when we're not a member of the affected tablet raft group - in that case we need to forward the statement twice - once to any replica of the affected tablet, then that replica can find the leader and return this information to the coordinator, which allows the second request to be directed to the leader.
This feature also allows passing through exception messages which happened on the target replica while executing the statement. For that, many methods of the `cql_transport::cql_server::connection` for creating error responses needed to be moved to `cql_transport::cql_server`. And for final exception handling on the coordinator, we added additional error info to the RPC response, so that the handling can be performed without having the `result_message::exception` or `exception_ptr` itself.
Fixes [SCYLLADB-71](https://scylladb.atlassian.net/browse/SCYLLADB-71)
[SCYLLADB-71]: https://scylladb.atlassian.net/browse/SCYLLADB-71?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQClosesscylladb/scylladb#27517
* github.com:scylladb/scylladb:
test: add tests for CQL forwarding
transport: enable CQL forwarding for strong consistency statements
transport: add remote statement preparation for CQL forwarding
transport: handle redirect responses in CQL forwarding
transport: add exception handling for forwarded CQL requests
transport: add basic CQL request forwarding
idl: add a representation of client_state for forwarding
cql_server: handle query, execute, batch in one case
transport: inline process_on_shard in cql_server::process
transport: extract process() to cql_server
transport: add messaging_service to cql_server
transport: add response reconstruction helpers for forwarding
transport: generalize the bounce result message for bouncing to other nodes
strong consistency: redirect requests to live replicas from the same rack
transport: pass foreign_ptr into sleep_until_timeout_passes and move it to cql_server
transport: extract the error handling from process_request_one
transport: move error response helpers from connection to cql_server
Forwarding CQL requests is not implemented yet, but we're already
prepared to return the target to forward to when trying to execute
strongly consistent requests. Currently, if we're not a replica
of the affected tablet, we redirect the request to the first replica
in the list.
This is not optimal, because this replica may be down or it may be
in another rack, making us perform cross-rack requests during forwarding.
Instead, we should forward the request to the replica from the same
rack and handle the case where the replica is down.
In this patch we change the replica selection for forwarding strongly
consistent requests, so that when the coordinator isn't a replica, it
redirects the request to the replica from the same rack.
If the replica from the same rack is down, or there is no replica in
our rack, we choose the next closest replica (preferring same-DC replicas
over other DCs). If no replica is alive, the query fails - the driver
should retry when some replica comes back up.
This series adds a global read barrier to raft_group0_client, ensuring that Raft group0 mutations are applied on all live nodes before returning to the caller.
Currently, after a group0_batch::commit, the mutations are only guaranteed to be applied on the leader. Other nodes may still be catching up, leading to stale reads. This patch introduces a broadcast read barrier mechanism. Calling send_group0_read_barrier_to_live_members after committing will cause the coordinator to send a read barrier RPC to all live nodes (discovered via gossiper) and waits for them to complete. This is best effort attempt to get cluster-wide visibility of the committed state before the response is returned to the user.
Auth and service levels write paths are switched to use this new mechanism.
Fixes https://scylladb.atlassian.net/browse/SCYLLADB-650
Backport: no, new feature
Closesscylladb/scylladb#28731
* https://github.com/scylladb/scylladb:
test: add tests for global group0_batch barrier feature
qos: switch service levels write paths to use global group0_batch barrier
auth: switch write paths to use global group0_batch barrier
raft: add function to broadcast read barrier request
raft: add gossiper dependency to raft_group0_client
raft: add read barrier RPC
Simplify code by getting rid of group0_upgrade_state since upgrade is no
longer supported, so no need to track its state. The none upgraded node
will simply not boot and to detect that the patch checks the state
directly from the system table.
Both migration manager and system keyspace will be used in next commit.
The first one is needed to execute group0 read barrier and we need
system keyspace to get column mappings.
This patch series removes creation of default 'cassandra:cassandra' superuser on system start.
Disable creation of a superuser with default 'cassandra:cassandra' credentials to improve security. The current flow requires clients to create another superuser and then drop the default `cassandra:cassandra' role. For those who do, there is a time window where the default credentials exist. For those who do not, that role stays. We want to improve security by forcing the client to either use config to specify default values for default superuser name and password or use cqlsh over maintenance socket connection to explicitly create/alter a superuser role.
The patch series:
- Enable role modification over the maintenance socket
- Stop using default 'cassandra' value for default superuser, skipping creation instead
Design document: https://scylladb.atlassian.net/wiki/spaces/RND/pages/165773327/Drop+default+cassandra+superuserFixesscylladb/scylla-enterprise#5657
This is an improvement. It does not need a backport.
Closesscylladb/scylladb#27215
* github.com:scylladb/scylladb:
config: enable maintenance socket in workdir by default
docs: auth: do not specify password with -p option
docs: update documentation related to default superuser
test: maintenance socket role management
test: cluster: add logs to test_maintenance_socket.py
test: pylib: fix connect_driver handling when adding and starting server
auth: do not create default 'cassandra:cassandra' superuser
auth: remove redundant DEFAULT_USER_NAME from password authenticator
auth: enable role management operations via maintenance socket
client_state: add has_superuser method
client_state: add _bypass_auth_checks flag
auth: let maintenance_socket_role_manager know if node is in maintenance mode
auth: remove class registrator usage
auth: instantiate auth service with factory functors
auth: add service constructor with factory functors
auth: add transitional.hh file
service: qos: handle special scheduling group case for maintenance socket
service: qos: use _auth_integration as condition for using _auth_integration
In this series we introduce new system tables and use them for storing the raft metadata
for strongly consistent tables. In contrast to the previously used raft group0 tables, the
new tables can store data on any shard. The tables also allow specifying the shard where
each partition should reside, which enables the tablets of strongly consistent tables to have
their raft group metadata co-located on the same shard as the tablet replica.
The new tables have almost the same schemas as the raft group0 tables. However, they
have an additional column in their partition keys. The additional column is the shard
that specifies where the data should be located. While a tablet and its corresponding
raft group server resides on some shard, it now writes and reads all requests to the
metadata tables using its shard in addition to the group_id.
The extra partition key column is used by the new partitioner and sharder which allow
this special shard routing. The partitioner encodes the shard in the token and the
sharder decodes the shard from the token. This approach for routing avoids any
additional lookups (for the tablet mapping) during operations on the new tables
and it also doesn't require keeping any state. It also doesn't interact negatively
with resharding - as long as tablets (and their corresponding raft metadata) occupy
some shard, we do not allow starting the node with a shard count lower than the
id of this shard. When increasing the shard count, the routing does not change,
similarly to how tablet allocation doesn't change.
To use the new tables, a new implementation of `raft::persistence` is added. Currently,
it's almost an exact copy of the `raft_sys_table_storage` which just uses the new tables,
but in the future we can modify it with changes specific to metadata (or mutation)
storage for strongly consistent tables. The new storage is used in the `groups_manager`,
which combined with the removal of some `this_shard_id() == 0` checks, allows strongly
consistent tables to be used on all shards.
This approach for making sure that the reads/writes to the new tables end up on the correct shards
won in the balance of complexity/usability/performance against a few other approaches we've considered.
They include:
1. Making the Raft server read/write directly to the database, skipping the sharder, on its shard, while using
the default partitioner/sharder. This approach could let us avoid changing the schema and there should be
no problems for reads and writes performed by the Raft server. However, in this approach we would input
data in tables conflicting with the placement determined by the sharder. As a result, any read going through
the sharder could miss the rows it was supposed to read. Even when reading all shards to find a specific value,
there is a risk of polluting the cache - the rows loaded on incorrect shards may persist in the cache for an unknown
amount of time. The cache may also mistakenly remember that a row is missing, even though it's actually present,
just on an incorrect shard.
Some of the issues with this approach could be worked around using another sharder which always returns
this_shard_id() when asked about a shard. It's not clear how such a sharder would implement a method like
`token_for_next_shard`, and how much simpler it would be compared to the current "identity" sharder.
2. Using a sharder depending on the current allocation of tablets on the node. This approach relies on the
knowledge of group_id -> shard mapping at any point in time in the cluster. For this approach we'd also
need to either add a custom partitioner which encodes the group_id in the token, or we'd need to track the
token(group_id) -> shard mapping. This approach has the benefit over the one used in the series of keeping
the partition key as just group_id. However, it requires more logic, and the access to the live state of the node
in the sharder, and it's not static - the same token may be sharded differently depending on the state of the
node - it shouldn't occur in practice, but if we changed the state of the node before adjusting the table data,
we would be unable to access/fix the stale data without artificially also changing the state of the node.
3. Using metadata tables co-located to the strongly consistent tables. This approach could simplify the
metadata migrations in the future, however it would require additional schema management of all co-located
metadata tables, and it's not even obvious what could be used as the partition key in these tables - some
metadata is per-raft-group, so we couldn't reuse the partition key of the strongly consistent table for it. And
finding and remembering a partition key that is routed to a specific shard is not a simple task. Finally, splits
and merges will most likely need special handling for metadata anyway, so we wouldn't even make use of
co-located table's splits and merges.
Fixes [SCYLLADB-361](https://scylladb.atlassian.net/browse/SCYLLADB-361)
[SCYLLADB-361]: https://scylladb.atlassian.net/browse/SCYLLADB-361?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQClosesscylladb/scylladb#28509
* github.com:scylladb/scylladb:
docs: add strong consistency doc
test/cluster: add tests for strongly-consistent tables' metadata persistence
raft: enable multi-shard raft groups for strongly consistent tablets
test/raft: add unit tests for raft_groups_storage
raft: add raft_groups_storage persistence class
db: add system tables for strongly consistent tables' raft groups
dht: add fixed_shard_partitioner and fixed_shard_sharder
raft: add group_id -> shard mapping to raft_group_registry
schema: add with_sharder overload accepting static_sharder reference
Changes the behavior of default superuser creation.
Previously, without configuration 'cassandra:cassandra' credentials
were used. Now default superuser creation is skipped if not configured.
The two ways to create default superuser are:
- Config file - auth_superuser_name and auth_superuser_salted_password fields
- Maintenance socket - connect over maintenance socket and CREATE/ALTER ROLE ...
Behavior changes:
Old behavior:
- No config - 'cassandra:cassandra' created
- auth_superuser_name only - <name>:cassandra created
- auth_superuser_salted_password only - 'cassandra:<password>' created
- Both specified - '<name>:<password>' created
New behavior:
- No config - no default superuser
- Requires maintenance socket setup
- auth_superuser_name only - '<name>:' created WITHOUT password
- Requires maintenance socket setup
- auth_superuser_salted_password only - no default superuser
- Both specified - '<name>:<password>' created
Fixes SCYLLADB-409
This patch removes class registrator usage in auth module.
It is not used after switching to factory functor initialization
of auth service.
Several role manager, authenticator, and authorizer name variables
are returned as well, and hardcoded inside qualified_java_name method,
since that is the only place they are ever used.
Refs SCYLLADB-409
Auth service is instantiated with the constructor that accepts
service_config, which then uses class registrator to instantiate
authorizer, authenticator, and role manager.
This patch switches to instantiating auth service via the constructor
that accepts factory functors. This is a step towards removing
usage of class registrator.
Refs SCYLLADB-409
3f7ee3ce5d introduced system.batchlog_v2, with a schema designed to speed up batchlog replays and make post-replay cleanups much more effective.
It did not introduce a cluster feature for the new table, because it is node local table, so the cluster can switch to the new table gradually, one node at a time.
However, https://github.com/scylladb/scylladb/issues/27886 showed that the switching causes timeouts during upgrades, in mixed clusters. Furthermore, switching to the new table unconditionally on upgrades nodes, means that on rollback, the batches saved into the v2 table are lost.
This PR introduces re-introduces v1 (`system.batchlog`) support and guards the use of the v2 table with a cluster feature, so mixed clusters keep using v1 and thus be rollback-compatible.
The re-introduced v1 support doesn't support post-replay cleanups for simplicity. The cleanup in v1 was never particularly effective anyway and we ended up disabling it for heavy batchlog users, so I don't think the lack of support for cleanup is a problem.
Fixes: https://github.com/scylladb/scylladb/issues/27886
Needs backport to 2026.1, to fix upgrades for clusters using batches
Closesscylladb/scylladb#28736
* github.com:scylladb/scylladb:
test/boost/batchlog_manager_test: add tests for v1 batchlog
test/boost/batchlog_manager_test: make prepare_batches() work with both v1 and v2
test/boost/batchlog_manager_test: fix indentation
test/boost/batchlog_manager_test: extract prepare_batches() method
test/lib/cql_assertions: is_rows(): add dump parameter
tools/scylla-sstable: extract query result printers
tools/scylla-sstable: add std::ostream& arg to query result printers
repair/row_level: repair_flush_hints_batchlog_handler(): add all_replayed to finish log
db/batchlog_manager: re-add v1 support
db/batchlog_manager: return all_replayed from process_batch()
db/batchlog_manager: process_bath() fix indentation
db/batchlog_manager: make batch() a standalone function
db/batchlog_manager: make structs stats public
db/batchlog_manager: allocate limiter on the stack
db/batchlog_manager: add feature_service dependency
gms/feature_service: add batchlog_v2 feature
Most functions of the new storage for raft groups for strongly
consistent tables are the same as for the system raft table
storage, so we reuse the tests for them to test the new storage.
We add additional tests for checking the new raft groups partitioner
and sharder, and for verifying that writes using storages for different
shards do not affect the data read on different shards.
We also add a test for checking the snapshot_descriptor present after
the storage bootstrap - for both system and strongly consistent storages
we check that the storage contains the initial descriptor.
Due to lack of checks present in process_execute_internal from
transport/server.cc needs_authorization bool was always set to true
doing some extra work (check_access()) for each request.
We mirror the logic in this patch in test env which perf-simple-query
uses. This can also potentially improve runtime of unittests (marginally).
Note that bug is only in perf tool not scylla itself, the fix
decreases insns/op by around 10%:
Before: 41065 insns/op
After: 37452 insns/op
Command: ./build/release/scylla perf-simple-query --duration 5 --smp 1
Fixes https://github.com/scylladb/scylladb/issues/27941Closesscylladb/scylladb#28704
This patchset replaces permissions cache based on loading_cache with a new unified (permissions and roles), full, coherent auth cache.
Reason for the change is that we want to improve scenarios under stress and simplify operation manuals. New cache doesn't require any tweaking. And it behaves particularly better in scenarios with lots of schema entities (e.g. tables) combined with unprepared queries. Old cache can generate few thousands of extra internal tps due to cache refresh.
Benchmark of unprepared statements (just to populate the cache) with 1000 tables shows 3k tps of internal reads reduction and 9.1% reduction of median instructions per op. So many tables were used to show resource impact, cache could be filled with other resource types to show the same improvement.
Backport: no, it's a new feature.
Fixes https://github.com/scylladb/scylladb/issues/7397
Fixes https://github.com/scylladb/scylladb/issues/3693
Fixes https://github.com/scylladb/scylladb/issues/2589
Fixes https://scylladb.atlassian.net/browse/SCYLLADB-147Closesscylladb/scylladb#28078
* github.com:scylladb/scylladb:
test: boost: add auth cache tests
auth: add cache size metrics
docs: conf: update permissions cache documentation
auth: remove old permissions cache
auth: use unified cache for permissions
auth: ldap: add permissions reload to unified cache
auth: add permissions cache to auth/cache
auth: add service::revoke_all as main entry point
auth: explicitly life-extend resource in auth_migration_listener
Fixes parsing of comma-separated seed lists in "init.cc" and "cql_test_env.cc" to use the standard `split_comma_separated_list` utility, avoiding manual `npos` arithmetic. The previous code relied on `npos` being `uint32_t(-1)`, which would not overflow in `uint64_t` target and exit the loop as expected. With Seastar's upcoming change to make `npos` `size_t(-1)`, this would wrap around to zero and cause an infinite loop.
Switch to `split_comma_separated_list` standardized way of tokenization that is also used in other places in the code. Empty tokens are handled as before. This prevents startup hangs and test failures when Seastar is updated.
The other commit also removes the unnecessary creation of temporary `gms::inet_address()` objects when calling `std::set<gms::inet_address>::emplace()`.
Refs: https://github.com/scylladb/seastar/pull/3236
No backport: The problem will only appear in master after the Seastar will be upgraded. The old code works with the Seastar before https://github.com/scylladb/seastar/pull/3236 (although by accident because of different integer bitsizes).
Closesscylladb/scylladb#28573
* github.com:scylladb/scylladb:
init: fix infinite loop on npos wrap with updated Seastar
init: remove unnecessary object creation in emplace calls
Fixes parsing of comma-separated seed lists in "init.cc" and
"cql_test_env.cc" to use the standard `split_comma_separated_list`
utility, avoiding manual `npos` arithmetic. The previous code relied on
`npos` being `uint32_t(-1)`, which would not overflow in `uint64_t`
target and exit the loop as expected. With Seastar's upcoming change
to make `npos` `size_t(-1)`, this would wrap around to zero and cause
an infinite loop.
Switch to `split_comma_separated_list` standardized way of tokenization
that is also used in other places in the code. Empty tokens are handled
as before. This prevents startup hangs and test failures when Seastar is
updated.
Refs: scylladb/seastar#3236
Some storage_service rpc verbs may checks that a handler is executed
inside gossiper scheduling group. For that, the expected group is
grabbed from database.
This patch puts the gossiper sched group into debug namespace and makes
this check use it from there. It removes one more place that uses
database as config provider.
Refs #28410
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Closesscylladb/scylladb#28427
The patch marks force-gossip-topology-changes as deprecated and removes
tests that use it. There is one test (test_different_group0_ids) which
is marked as xfail instead since it looks like gossiper mode was used
there as a way to easily achieve a certain state, so more investigation
is needed if the tests can be fixed to use raft mode instead.
Closesscylladb/scylladb#28383
In a lambda returned from make_streaming_consumer() there's a check for
current scheudling group being streaming one. It came from #17090 where
streaming code was launched in wrong sched group thus affecting user
groups in a bad way.
The check is nice and useful, but it abuses replica::database by getting
unrelated information from it.
To preserve the check and to stop using database as provider of configs,
keep the streaming scheduling group handle in the debug namespace. This
emphasises that this global variable is purely for debugging purposes.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Closesscylladb/scylladb#28410
In this PR we add a basic implementation of the strongly-consistent tables:
* generate raft group id when a strongly-consistent table is created
* persist it into system.tables table
* start raft groups on replicas when a strongly-consistent tablet_map reaches them
* add strongly-consistent version of the storage_proxy, with the `query` and `mutate` methods
* the `mutate` method submits a command to the tablets raft group, the query method reads the data with `raft.read_barrier()`
* strongly-consistent versions of the `select_statement` and `modification_statement` are added
* a basic `test_strong_consistency.py/test_basic_write_read` is added which to check that we can write and read data in a strongly consistent fashion.
Limitations:
* for now the strongly consistent tables can have tablets only on shard zero. This is because we (ab/re) use the existing raft system tables which live only on shard0. In the next PRs we'll create separate tables for the new tablets raft groups.
* No Scylla-side proxying - the test has to figure out who is the leader and submit the command to the right node. This will be fixed separately.
* No tablet balancing -- migration/split/merges require separate complicated code.
The new behavior is hidden behind `STRONGLY_CONSISTENT_TABLES` feature, which is enabled when the `STRONGLY_CONSISTENT_TABLES` experimental feature flag is set.
Requirements, specs and general overview of the feature can be found [here](https://scylladb.atlassian.net/wiki/spaces/RND/pages/91422722/Strong+Consistency). Short term implementation plan is [here](https://docs.google.com/document/d/1afKeeHaCkKxER7IThHkaAQlh2JWpbqhFLIQ3CzmiXhI/edit?tab=t.0#heading=h.thkorgfek290)
One can check the strongly consistent writes and reads locally via cqlsh:
scylla.yaml:
```
experimental_features:
- strongly-consistent-tables
```
cqlsh:
```
CREATE KEYSPACE IF NOT EXISTS my_ks WITH replication = {'class': 'NetworkTopologyStrategy', 'replication_factor': 1} AND tablets = {'initial': 1} AND consistency = 'local';
CREATE TABLE my_ks.test (pk int PRIMARY KEY, c int);
INSERT INTO my_ks.test (pk, c) VALUES (10, 20);
SELECT * FROM my_ks.test WHERE pk = 10;
```
Fixes SCYLLADB-34
Fixes SCYLLADB-32
Fixes SCYLLADB-31
Fixes SCYLLADB-33
Fixes SCYLLADB-56
backport: no need
Closesscylladb/scylladb#27614
* https://github.com/scylladb/scylladb:
test_encryption: capture stderr
test/cluster: add test_strong_consistency.py
raft_group_registry: disable metrics for non-0 groups
strong consistency: implement select_statement::do_execute()
cql: add select_statement.cc
strong consistency: implement coordinator::query()
cql: add modification_statement
cql: add statement_helpers
strong consistency: implement coordinator::mutate()
raft.hh: make server::wait_for_leader() public
strong_consistency: add coordinator
modification_statement: make get_timeout public
strong_consistency: add groups_manager
strong_consistency: add state_machine and raft_command
table: add get_max_timestamp_for_tablet
tablets: generate raft group_id-s for new table
tablet_replication_strategy: add consistency field
tablets: add raft_group_id
modification_statement: remove virtual where it's not needed
modification_statement: inline prepare_statement()
system_keyspace: disable tablet_balancing for strongly_consistent_tables
cql: rename strongly_consistent statements to broadcast statements
If tablets are enabled via db::config add the `tablet = {'enabled': true}'
option when creating a keyspace, even if `cql_test_config.initial_tablets`
is disengaged.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
In PR 5b6570be52 we introduced the config option `sstable_compression_user_table_options` to allow adjusting the default compression settings for user tables. However, the new option was hooked into the CQL layer and applied only to CQL base tables, not to the whole spectrum of user tables: CQL auxiliary tables (materialized views, secondary indexes, CDC log tables), Alternator base tables, Alternator auxiliary tables (GSIs, LSIs, Streams).
This gap also led to inconsistent default compression algorithms after we changed the option’s default algorithm from LZ4 to LZ4WithDicts (adf9c426c2).
This series introduces a general “schema initializer” mechanism in `schema_builder` and uses it to apply the default compression settings uniformly across all user tables. This ensures that all base and aux tables take their default compression settings from config.
Fixes#26914.
Backport justification: LZ4WithDicts is the new default since 2025.4, but the config option exists since 2025.2. Based on severity, I suggest we backport only to 2025.4 to maintain consistency of the defaults.
Closesscylladb/scylladb#27204
* github.com:scylladb/scylladb:
db/config: Update sstable_compression_user_table_options description
schema: Add initializer for compression defaults
schema: Generalize static configurators into schema initializers
schema: Initialize static properties eagerly
db: config: Add accessor for sstable_compression_user_table_options
test: Check that CQL and Alternator tables respect compression config
Add the `coordinator` class, which will be responsible for coordinating
reads and writes to strongly consistent tables. This commit includes
only the boilerplate; the methods will be implemented in separate
commits.
This patch changes the layout of user-facing scheduling groups from
/
`- statement
`- sl:default
`- sl:*
`- other groups (compaction, streaming, etc.)
into
/
`- user (supergroup)
`- statement
`- sl:default
`- sl:*
`- other groups (compaction, streaming, etc.)
The new supergroup has 1000 static shares and is name-less, in a sense
that it only have a variable in the code to refer to and is not exported
via metrics (should be fixed in seastar if we want to).
The moved groups don't change their names or shares, only move inside
the scheduling hierarchy.
The goal of the change is to improve resource consumption of sl:*
groups. Right now activities in low-shares service levels are scheduled
on-par with e.g. streaming activity, which is considered to be low-prio
one. By moving all sl:* groups into their own supergroup with 1000
shares changes the meaning of sl:* shares. From now on these shares
values describe preirities of service level between each-other, and the
user activities compete with the rest of the system with 1000 shares,
regardless of how many service levels are there.
Unit tests keep their user groups under root supergroup (for simplicity)
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Closesscylladb/scylladb#28235
In PR 5b6570be52 we introduced the config option
`sstable_compression_user_table_options` to allow adjusting the default
compression settings for user tables. However, the new option was hooked
into the CQL layer and applied only to CQL base tables, not to the whole
spectrum of user tables: CQL auxiliary tables (materialized views,
secondary indexes, CDC log tables), Alternator base tables, Alternator
auxiliary tables (GSIs, LSIs, Streams).
Fix this by moving the logic into the `schema_builder` via a schema
initializer. This ensures that the default compression settings are
applied uniformly regardless of how the table is created, while also
keeping the logic in a central place.
Register the initializer at startup in all executables where schemas are
being used (`scylla_main()`, `scylla_sstable_main()`, `cql_test_env`).
Finally, remove the ad-hoc logic from `create_table_statement`
(redundant as of this patch), remove the xfail markers from the relevant
tests and adjust `test_describe_cdc_log_table_create_statement` to
expect LZ4WithDicts as the default compressor.
Fixes#26914.
Signed-off-by: Nikos Dragazis <nikolaos.dragazis@scylladb.com>
Allow creating materialized views and secondary indexes in a tablets keyspace only if it's RF-rack-valid, and enforce RF-rack-validity while the keyspace has views by restricting some operations:
* Altering a keyspace's RF if it would make the keyspace RF-rack-invalid
* Adding a node in a new rack
* Removing / Decommissioning the last node in a rack
Previously the config option `rf_rack_valid_keyspaces` was required for creating views. We now remove this restriction - it's not needed because we always maintain RF-rack-validity for keyspaces with views.
The restrictions are relevant only for keyspaces with numerical RF. Keyspace with rack-list-based RF are always RF-rack-valid.
Fixesscylladb/scylladb#23345
Fixes https://github.com/scylladb/scylladb/issues/26820
backport to relevant versions for materialized views with tablets since it depends on rf-rack validity
Closesscylladb/scylladb#26354
* github.com:scylladb/scylladb:
docs: update RF-rack restrictions
cql3: don't apply RF-rack restrictions on vector indexes
cql3: add warning when creating mv/index with tablets about rf-rack
service/tablet_allocator: always allow tablet merge of tables with views
locator: extend rf-rack validation for rack lists
test: test rf-rack validity when creating keyspace during node ops
locator: fix rf-rack validation during node join/remove
test: test topology restrictions for views with tablets
test: add test_topology_ops_with_rf_rack_valid
topology coordinator: restrict node join/remove to preserve RF-rack validity
topology coordinator: add validation to node remove
locator: extend rf-rack validation functions
view: change validate_view_keyspace to allow MVs if RF=Racks
db: enforce rf-rack-validity for keyspaces with views
replica/db: add enforce_rf_rack_validity_for_keyspace helper
db: remove enforce parameter from check_rf_rack_validity
test: adjust test to not break rf-rack validity
Auth cache loading at startup is racing between
auth service and raft code and it doesn't support
concurrency causing it to crash.
We can't easily remove any of the places as during
raft recovery snapshot is not loaded and it relies
on loading cache via auth service. Therefore we add
semaphore.
Fixes https://github.com/scylladb/scylladb/issues/27540Closesscylladb/scylladb#27573
The function validate_view_keyspace checks if a keyspace is eligible for
having materialized views, and it is used for validation when creating a
MV or a MV-based index.
Previously, it was required that the rf_rack_valid_keyspaces option is
set in order for tablets-based keyspaces to be considered eligible, and
the RF-rack condition was enforced when the option is set.
Instead of this, we change the validation to allow MVs in a keyspace if
the RF-rack condition is satisfied for the keyspace - regardless of the
config option.
We remove the config validation for views on startup that validates the
option `rf_rack_valid_keyspaces` is set if there are any views with
tablets, since this is not required anymore.
We can do this without worrying about upgrades because this change will
be effective from 2025.4 where MVs with tablets are first out of
experimental phase.
We update the test for MV and index restrictions in tablets keyspaces
according to the new requirements.
* Create MV/index: previously the test checked that it's allowed only if
the config option `rf_rack_valid_keyspaces` is set. This is changed
now so it's always allowed to create MV/index if the keyspace is
RF-rack-valid. Update the test to verify that we can create MV/index
when the keyspace is RF-rack-valid, even if the rf_rack option is not
set, and verify that it fails when the keyspace is RF-rack-invalid.
* Alter: Add a new test to verify that while a keyspace has views, it
can't be altered to become RF-rack-invalid.
simple refactoring: the enforce parameter is always given the value of
the `rf_rack_valid_keyspaces` option. remove the parameter and use the
option value directly from the db config.
this will be useful for a later change to the enforcement conditions.
`system.client_routes` is a system table that sets the target address and ports for each `host_id`, for one or more connection (e.g., Private Link) represented by `connection_id`. Cloud will write the table via REST, and drivers will read it via CQL to override values obtained from `system.local` and `system.peers`.
This patch series contains:
- Introduction of `CLIENT_ROUTES` feature flag.
- Implementation of raft-based `system.client_routes` table
- Implementation of `v2/client-routes` POST/DELETE/GET endpoints
- Implementation of new `CLIENT_ROUTES_CHANGE` event that is sent to drivers when `system.client_routes` is changed
- New tests that verifies the aforementioned features
Ref: scylladb/scylla-enterprise#5699
For now, no automatic backport. However, the changes are planned to be release on `2025.4` either as a backport or a private build.
Closesscylladb/scylladb#27323
* https://github.com/scylladb/scylladb:
docs: describe CLIENT_ROUTES_CHANGE extension
test: add test for CLIENT_ROUTES event
service: transport: add CLIENT_ROUTES_CHANGE event
test: add cluster tests for client routes
test: add API tests for client_routes endpoints
test: add `timeout` parameter to `delete` in RESTClient
test: allow json_body in send
api: implement client_routes endpoints
api: add client_routes.json
service: main: add client_routes_service
db: add system.client_routes table
gms: add CLIENT_ROUTES feature
Introduce the CLIENT_ROUTES_CHANGE event to let drivers refresh
connections when `system.client_routes` is modified. Some deployments
(e.g., Private Link) require specific address/port mappings that can
change without topology changes and drivers need to adapt promptly
to avoid connectivity issues.
This new EVENT type carries a change indicator plus the affected
`connection_ids` and `host_ids`. The only change value is
`UPDATE_NODES`, meaning one or more client routes were inserted,
updated, or deleted.
Drivers subscribe using the existing events mechanism, so no additional
`cql_protocol_extension` key is required.
Ref: scylladb/scylla-enterprise#5699
The batchlog table contains an entry for each logged batch that is processed by the local node as coordinator. These entries are typically very short lived, they are inserted when the batch is processed and deleted immediately after the batch is successfully applied.
When a table has `tombstone_gc = {'mode': 'repair'}` enabled, every repair has to flush all hints and batchlogs, so that we can be certain that there is no live data in any of these, older than the last repair. Since batches can contain member queries from any number of tables, the whole batchlog has to be flushed, even if repair-mode tombstone-gc is enabled for a single table.
Flushing the batchlog table happens by doing a batchlog replay. This involves reading the entire content of this table, and attempting to replay+delete any live entries (that are old enough to be replayed). Under normal operating circumstances, 99%+ of the content of the batchlog table is partition tombstones. Because of this, scanning the content of this table has to process thousands to millions of tombstones. This was observed to require up to 20 minutes to finish, causing repairs to slow down to a crawl, as the batchlog-flush has to be repeated at the end of the repair of each token-range.
When trying to address this problem, the first idea was that we should expedite the garbage-collection of these accumulated tombstones. This experiment failed, see https://github.com/scylladb/scylladb/pull/23752. The commitlog proved to be an impossible to bypass barrier, preventing quick garbage-collection of tombstones. So long as a single commit-log segment is alive, holding content from the batchlog table, all tombstones written after are blocked from GC.
The second approach, represented by this PR, is to not rely in tombstone GC to reduce the tombstone amount. Instead restructure the table such that a single higher-order tombstone can be used to shadow and allow for the eviction of the myriads of individual batchlog entry tombstones. This is realized by reorganizing the batchlog table such that individual batches are rows, not partitions.
This new schema is introduced by the new `system.batchlog_v2` table, introduced by this PR:
CREATE TABLE system.batchlog_v2 (
version int,
stage int,
shard int,
written_at timestamp,
id uuid,
data blob,
PRIMARY KEY ((version, stage, shard), written_at, id));
The new schema organization has the following goals:
1) Make post-replay batchlog cleanup possible with a simple range-tombstone. This allows dropping the individual dead batchlog entries, as they are shadowed by a higher level tombstone. This enables dropping tombstones without tombstone GC.
2) To make the above possible, introduce the stage key component: batchlog entries that fail the first replay attempt, are moved to the failed_replay stage, so the initial stage can be cleaned up safely.
3) Spread out the data among Scylla shards, via the batchlog shard column.
4) Make batchlog entries ordered by the batchlog create time (id). This allows for selecting batchlogs to replay, without post-filtering of batchlogs that are too young to be replayed.
Fixes: https://github.com/scylladb/scylladb/issues/23358
This is an improvement, normally not a backport-candidate. We might override this and backport to allow wider use of `tombstone_gc: {'mode': 'repair'}`.
Closesscylladb/scylladb#26671
* github.com:scylladb/scylladb:
db/config: change batchlog_replay_cleanup_after_replays default to 1
test/boost/batchlog_manager_test: add test for batchlog cleanup
replica/mutation_dump: always set position weight for clustering positions
service/storage_proxy: s/batch_replay_throw/storage_proxy_fail_replay_batch/
test/lib: introduce error_injection.hh
utils/error_injection: add debug log to disable() and disable_all()
test/lib/cql_test_env: forward config to batchlog
test/lib/cql_test_env: add batch type to execute_batch()
test/lib/cql_assertions: add with_size(predicate) overload
test/lib/cql_assertions: add source location to fail messages
test/lib/cql_assertions: columns_assertions: add assert_for_columns_of_each_row()
test/lib/cql_assertions: rows_assertions::assert_for_columns_of_row(): add index bound check
test/lib/cql_assertions: columns_assertions: add T* with_typed_column() overload
db/batchlog_manager: config: s/write_timeout/reply_timeot/
db,service: switch to system.batchlog_v2
db/system_keyspace: introduce system.batchlog_v2
service,db: extract generation of batchlog delete mutation
service,db: extract get_batchlog_mutation_for() from storage-proxy
db/batchlog_manager: only consider propagation delay with tombstone-gc=repair
db/batchlog_manager: don't drop entire batch if one mutations' table was dropped
data_dictionary: table: add get_truncation_time()
db/batchlog_manager: batch(): replace map_reduce() with simple loop
db/batchlog_manager: finish coroutinizing replay_all_failed_batches
db/batchlog_manager: improve replayAllFailedBatches logs
