In get_children we get the vector of alive nodes with get_nodes.
Yet, between this and sending rpc to those nodes there might be
a preemption. Currently, the liveness of a node is checked once
again before the rpcs (only with gossiper not in topology - unlike
get_nodes).
Modify get_children, so that it keeps a token_metadata_ptr,
preventing topology from changing between get_nodes and rpcs.
Remove test_get_children as it checked if the get_children method
won't fail if a node is down after get_nodes - which cannot happen
currently.
Fixes: SCYLLADB-942
Adds an injection signal _from_ table::seal_active_memtable to allow us to
reliably wait for flushing. And does so.
Closesscylladb/scylladb#29070
Since commit 509f2af8db, gate_closed_exception can be triggered for ongoing split during shutdown. The commit is correct, but it causes split failure on shutdown to log an error, which causes CI instability. Previously, aborted_exception would be triggered instead which is logged as warning. Let's do the same.
Fixes https://scylladb.atlassian.net/browse/SCYLLADB-951.
Fixes https://github.com/scylladb/scylladb/issues/24850.
Only 2026.1 is affected.
Closesscylladb/scylladb#29032
* github.com:scylladb/scylladb:
replica: Demote log level on split failure during shutdown
service: Demote log level on split failure during shutdown
A followup of the merge of two test cases that happened in the previous
patch. Both used `foo = N if domain == bar else M` to evaluate the
parameters for topology. Using if-else block makes it immediately obvious
which topology and scope apply for each domain value without having to
evaluate multiple inline conditionals.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
The two tests differ only in the way they set up the topology for the
cluster and the post-restore checks against the resulting streams.
The merge happens with the help of a "scope_is_same" boolean parameter
and corresponding updates in the topology setup and post-checks.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
The one in "different domain" test is simpler because the test performs
less checks. Next patch will merge both tests and making regexp-s look
identical makes the merge even smother.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Verify that the directory listers opened by get_snapshot_details
are properly closed when handling an (injected) exception.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
NetworkTopologyStrategy is the preferred choice. We should not
use SimpleStrategy anymore. This patch changes the topology strategy
for all the maintenance socket tests.
Refs SCYLLADB-1070
Add a cql_clusters pytest fixture that tracks CQL driver Cluster
objects and shuts them down automatically after test completion.
This replaces manual shutdown() calls at the end of each test.
Also consolidate shutdown() calls in retry helpers into finally
blocks for consistent cleanup.
Refs SCYLLADB-1070
GRANT/REVOKE fails on the maintenance socket connections,
because maintenance_auth_service uses allow_all_authorizer.
allow_all_authorizer allows all operations, but not GRANT/REVOKE,
because they make no sense in its context.
This has been observed during PGO run failure in operations from
./pgo/conf/auth.cql file.
This patch introduces maintenance_socket_authorizer that supports
the capabilities of default_authorizer ('CassandraAuthorizer')
without needing authorization.
Refs SCYLLADB-1070
This patch is mostly for the purpose of running pgo CI job.
We may receive connection error if asyncio.sleep(5) in
pgo.py is not sufficient waiting time.
In pgo.py we do wait for port but only for cql,
anyway it's better to have high level check than
trying to wait for alternator port there.
Fixes https://scylladb.atlassian.net/browse/SCYLLADB-1071
Backport: 2026.1 - it failed on CI for that build
Closesscylladb/scylladb#29063
* github.com:scylladb/scylladb:
perf: add abort_source support to wait-for-port loops
perf-alternator: wait for alternator port before running workload
- fix s3::range max value for object size which is 50TiB and not 5.
- refactor constants to make it accessible for all interested parties, also reuse these constants in tests
No need to backport, doubt we will encounter an object larger than 5TiB
Closesscylladb/scylladb#28601
* github.com:scylladb/scylladb:
s3_client: reorganize tests in part_size_calculation_test
s3_client: switch using s3 limits constants in tests
s3_client: fix the s3::range max object size
s3_client: remove "aws" prefix from object limits constants
s3_client: make s3 object limits accessible
This test was observed to fail in CI recently but there is not enough information in the logs to figure out what went wrong. This PR makes a few improvements to make the next investigation easier, should it be needed:
* storage-service: add table name to mutation write failure error messages.
* database: the `database_apply` error injection used to cause trouble, catching writes to bystander tables, making tests flaky. To eliminate this, it gained a filter to apply only to non-system keyspaces. Unfortunately, this still allows it to catch writes to the trace tables. While this should not fail the test, it reduces observability, as some traces disappear. Improve this error injection to only apply to selected table. Also merge it with the `database_apply_wait` error injection, to streamline the code a bit.
* test/test_data_resurrection_in_memtable.py: dump data from the datable, before the checks for expected data, so if checks fail, the data in the table is known.
Refs: SCYLLADB-812
Refs: SCYLLADB-870
Fixes: SCYLLADB-1050 (by restricting `database_apply` error injection, so it doesn't affect writes to system traces)
Backport: test related improvement, no backport
Closesscylladb/scylladb#28899
* github.com:scylladb/scylladb:
test/cluster/test_data_resurrection_in_memtable.py: dump rows before check
replica/database: consolidate the two database_apply error injections
service/storage_proxy: add name of table to error message for write errors
Previously, all stream-table fixtures in test_streams.py used scope="function",
forcing a fresh table to be created for every test, slowing down the test a bit
(though not much), and discouraging writing small new tests.
This was a workaround for a DynamoDB quirk (that Alternator doesn't have):
LATEST shard iterators have a time slack and may point slightly before the true
stream head, causing leftover events from a previous test to appear in the next
test's reads.
The first two tests in this series fix small problems that turn up once we start
sharing test tables in test_streams.py. The final patch fixes the "LATEST" problem
and enables sharing the test table by using "module" scope fixtures instead of
"function".
After this series, test_streams.py run time went down a bit, from 20.2 seconds to 17.7 seconds.
Closesscylladb/scylladb#28972
* github.com:scylladb/scylladb:
test/alternator: speed up test_streams.py by using module-scope fixtures
test/alternator: test_streams.py don't use fixtures in 4 tests
test/alternator: fix do_test() in test_streams.py
This test relies on the cache entry being evicted after 200ms past the
TTL. This may not happen on a busy CI machine. Make the test less
reliant on timing by using eventually_true().
Simplify the test by dropping the second entry, it doesn't add anything
to the test.
Fixes: SCYLLADB-811
Closesscylladb/scylladb#28958
This fixtures starts the mock server and immediately connects to it to
setup the expected requests. The connection attempt might be too early,
so there is a retry loop with a timeout. The loop currently checks for
requests.exception.ConnectionError. We've seen a case where the
connection is successful but the request fails with 404. The mock
started the server but didn't setup the routes yet. Add a retry for http
404 to handle this.
Fixes: SCYLLADB-966
Closesscylladb/scylladb#29003
This series fixes a metrics visibility gap in Alternator and adds regression coverage.
Until now, BatchGetItem and BatchWriteItem updated global latency histograms but did not consistently update per-table latency histograms. As a result, table-level latency dashboards could miss batch traffic.
It updates the batch read/write paths to compute request duration once and record it in both global and per-table latency metrics.
Add the missing tests, including a metric-agnostic helper and a dedicated per-table latency test that verifies latency counters increase for item and batch operations.
This change is metrics-only (no API/behavior change for requests) and improves observability consistency between global and per-table views.
Fixes#28721
**We assume the alternator per-table metrics exist, but the batch ones are not updated**
Closesscylladb/scylladb#28732
* github.com:scylladb/scylladb:
test(alternator): add per-table latency coverage for item and batch ops
alternator: track per-table latency for batch get/write operations
Permits in the `waiting_for_memory` state represent already-executing reads that are blocked on memory allocation. Preemptively aborting them is wasteful -- these reads have already consumed resources and made progress, so they should be allowed to complete.
Restrict the preemptive abort check in maybe_admit_waiters() to only apply to permits in the `waiting_for_admission` state, and tighten the state validation in `on_preemptive_aborted()` accordingly.
Fixes: https://scylladb.atlassian.net/browse/SCYLLADB-1016
Backport not needed. The commit introducing replica load shedding is not part of 2026.1
Closesscylladb/scylladb#29025
* github.com:scylladb/scylladb:
reader_concurrency_semaphore: skip preemptive abort for permits waiting for memory
reader_concurrency_semaphore_test: detect memory leak on preemptive abort of waiting_for_memory permit
Check abort_source on each retry iteration in
wait_for_alternator and wait_for_cql so the
wait can be interrupted on shutdown.
Didn't use sleep_abortable as the sleep is very short
anyway.
Fixes: SCYLLADB-244
Disables snapshot control such that any active ops finish/fail
before proceeding with decommission.
Note: snapshot control provided as argument, not member ref
due to storage_service being used from both main and cql_test_env.
(The latter has no snapshot_ctl to provide).
Could do the snapshot lockout on API level, but want to do
pre-checks before this.
Note: this just disables backup/snapshot fully. Could re-enable
after decommission, but this seems somewhat pointless.
v2:
* Add log message to snapshot shutdown
* Make test use log waiting instead of timeouts
Closesscylladb/scylladb#28980
This patch is mostly for the purpose of running pgo CI job.
We may receive connection error if asyncio.sleep(5) in
pgo.py is not sufficient waiting time.
In pgo.py we do wait for port but only for cql,
anyway it's better to have high level check than
trying to wait for alternator port there.
Some tests, when create a cluster, configure nodes with the rf-rack-valid option, because sometimes they want to have it OFF. For that the option is explicitly carried around, but the cluster creating helper can guess this option itself -- out of the provided topology and replication factor.
Removing this option simplifies the code and (which a nicer outcome) the test "signature" that's used e.g. in command-line to run a specific test.
Improving tests, not backporting
Closesscylladb/scylladb#28860
* github.com:scylladb/scylladb:
test: Relax topology_rf_validity parameter for some tests
test: Auto detect rf-rack-valid option in create_cluster()
Dtest failed with:
table - Failed to load SSTable .../me-3gyn_0qwi_313gw2n2y90v2j4fcv-big-Data.db
of origin memtable due to std::runtime_error (Cannot split
.../me-3gyn_0qwi_313gw2n2y90v2j4fcv-big-Data.db because manager has compaction
disabled, reason might be out of space prevention), it will be unlinked...
The reason is that the error above is being triggered when the cause is
shutdown, not out of space prevention. Let's distinguish between the two
cases and log the error with warning level on shutdown.
Fixes https://github.com/scylladb/scylladb/issues/24850.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
`test_raft_no_quorum.py::test_cannot_add_new_node` is currently flaky in dev
mode. The bootstrap of the first node can fail due to `add_entry()` timing
out (with the 1s timeout set by the test case).
Other test cases in this test file could fail in the same way as well, so we
need a general fix. We don't want to increase the timeout in dev mode, as it
would slow down the test. The solution is to keep the timeout unchanged, but
set it only after quorum is lost. This prevents unexpected timeouts of group0
operations with almost no impact on the test running time.
A note about the new `update_group0_raft_op_timeout` function: waiting for
the log seems to be necessary only for
`test_quorum_lost_during_node_join_response_handler`, but let's do it
for all test cases just in case (including `test_can_restart` that shouldn't
be flaky currently).
Fixes https://scylladb.atlassian.net/browse/SCYLLADB-913Closesscylladb/scylladb#28998
Since commit 509f2af8db, gate_closed_exception can be triggered
for ongoing split during shutdown. The commit is correct, but it
causes split failure on shutdown to log an error, which causes
CI instability. Previously, aborted_exception would be triggered
instead which is logged as warning. Let's do the same.
Fixes https://scylladb.atlassian.net/browse/SCYLLADB-951.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
changes in this commit:
1)rename class from 'TestContext' to 'Context' so pytest will not consider this class as a test
2)extend pytest filterwarnings list to ignore warnings from external libs
3) use datetime.datetime.now(datetime.UTC) unstead datetime.datetime.utcnow()
4) use ResultSet.one() instead ResultSet[0]
Fixes SCYLLADB-904
Fixes SCYLLADB-908
Related SCYLLADB-902
Closesscylladb/scylladb#28956
The test assumes that the sleep duration will be at least the value of
the sleep parameter. However, the actual sleep time can be slightly less
than requested (e.g., a 100ms sleep request might result in a 99ms
sleep).
This commit adjusts the test's time comparison to be more lenient,
preventing test flakiness.
When a `with_connect` operation timed out, the underlying connection
attempt continued to run in the reactor. This could lead to a crash
if the connection was established/rejected after the client object had
already been destroyed. This issue was observed during the teardown
phase of a upcoming high-availability test case.
This commit fixes the race condition by ensuring the connection attempt
is properly canceled on timeout.
Additionally, the explicit TLS handshake previously forced during the
connection is now deferred to the first I/O operation, which is the
default and preferred behavior.
Fixes: SCYLLADB-832
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
Tests that call create_cluster() helper no longer need to carry the
rf-validity parameter. This simplifies the code and test signature.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
The helper accepts its as boolean argument, but it can easily estimate
one from the provided topology.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Permits in the `waiting_for_memory` state represent already-executing
reads that are blocked on memory allocation. Preemptively aborting
them is wasteful -- these reads have already consumed resources and
made progress, so they should be allowed to complete.
Restrict the preemptive abort check in maybe_admit_waiters() to only
apply to permits in the `waiting_for_admission` state, and tighten
the state validation in `on_preemptive_aborted()` accordingly.
Adjust the following tests:
+ test_reader_concurrency_semaphore_abort_preemptively_aborted_permit
no longer relies on requesting memory
+ test_reader_concurrency_semaphore_preemptive_abort_requested_memory_leak
adjusted to the fix
Fixes: https://scylladb.atlassian.net/browse/SCYLLADB-1016
This PR adds integrity verification for SSTable component files during loading. When component digests are present in Scylla metadata, the loader now validates each component's CRC32 digest against the stored expected value, catching silent corruption of component files. Index, Rows and Partitions components digests are also validated duriung scrub in validate mode
Added corruption tests that write an SSTable, flip a bit in a specific component file, then verify that reloading the SSTable detects the corruption and throws the expected exception.
Depends on https://github.com/scylladb/scylladb/pull/28338
Backport is not required, this is new feature
Fixes https://github.com/scylladb/scylladb/issues/20103Closesscylladb/scylladb#28761
* github.com:scylladb/scylladb:
test/cqlpy: test --ignore-component-digest-mismatch flag in scylla sstable upgrade
docs: document --ignore-component-digest-mismatch flag for scylla sstable upgrade
sstables: propagate ignore_component_digest_mismatch config to all load sites
sstables: add option to ignore component digest mismatches
sstable_compaction_test: Add scrub validate test for corrupted index
sstables: add tests for component digest validation on corrupted SSTables
sstables: validate index components digests during SSTable scrub in validate mode
sstables: verify component digests on SSTable load
sstables: add digest_file_random_access_reader for CRC32 digest computation
Fix several test cases that did not await async tasks:
- test_restart_leaving_replica_during_cleanup
- test_restart_in_cleanup_stage_after_cleanup
- test_tablet_back_and_forth_migration
- test_staging_backlog_is_preserved_with_file_based_streaming
Fixes SCYLLADB-910
* Minor fixes, no backport needed
Closesscylladb/scylladb#28908
* github.com:scylladb/scylladb:
test_tablets_migration: test_staging_backlog_is_preserved_with_file_based_streaming: convert for loop to asyncio.gather
test_tablets_migration: test_tablet_back_and_forth_migration: await move_tablet
test_tablets_migration: test_restart_in_cleanup_stage_after_cleanup: await move_task
test_tablets_migration: test_restart_leaving_replica_during_cleanup: await move_task
test_tablets_migration: drop unused imports from cassandra.query
Fixes#25084
Add slirp4netns and use for nested containers. This will allow nested container port aliasing, helping CI stability.
Note: this contains and updated Dockerfile for dbuild image, but since chicken and eggs, right now will force install slirp4netns before anything in dbuild script.
Updates the mock server handling to use ephemeral ports and query from container, ensuring we don't get port collisions. (boost as well as pytest).
Includes a timeout up, and a tweak to our scylla_cluster handling, ensuring we don't deadlock when pipe size is less than requires for our sys notify messages.
Closesscylladb/scylladb#28727
* github.com:scylladb/scylladb:
gcs_fixture: Change to use docker helper
aws_kms_fixture: Modify to use docker helper
test/lib/proc_util: Add docker helper
pytest: use ephemeral port publish for docker mock servers
dbuild: Use container network in dbuild nested containers
scylla_cluster: Read notify sock in background to prevent deadlock
A few days ago, in commit 7b30a39 we added to pytest.ini the option
xfail_strict. This option causes every time a test XPASSes, i.e., an xfail
test actually passes - to be considered an error and fail the test.
But some tests demonstrate a timing-related bug and do not reproduce the
bug every single time. An example we noticed in one CI run is:
test/cluster/test_alternator.py::test_alternator_concurrent_rmw_same_partition_different_server
This test reproduces a timing-related bug (if you do an LWT write to
one partition on to two different coordinators "at the same time", you
can get a failure), but only most of the time, not 100% of the time.
The solution is to add "strict=False" for the xfail marker on this specific
test. This undoes the xfail_strict for this specific test, accepting that
this specific test can either pass or fail. Note that this does NOT make
this test worthless - we still see this test failing most of the time, and
when a developer finally fixes this issue, the test will begin to pass all
the time.
Fixes https://scylladb.atlassian.net/browse/SCYLLADB-941
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Closesscylladb/scylladb#29016
When it deadlocks, groups stop merging and compaction group merge
backlog will run-away.
Also, graceful shutdown will be blocked on it.
Found by flaky unit test
test_merge_chooses_best_replica_with_odd_count, which timed-out in 1
in 100 runs.
Reason for deadlock:
When storage groups are merged, the main compaction group of the new
storage group takes a compaction lock, which is appended to
_compaction_reenablers_for_merging, and released when the merge
completion fiber is done with the whole batch.
If we accumulate more than 1 merge cycle for the fiber, deadlock
occurs. Lock order will be this
Initial state:
cg0: main
cg1: main
cg2: main
cg3: main
After 1st merge:
cg0': main [locked], merging_groups=[cg0.main, cg1.main]
cg1': main [locked], merging_groups=[cg2.main, cg3.main]
After 2nd merge:
cg0'': main [locked], merging_groups=[cg0'.main [locked], cg0.main, cg1.main, cg1'.main [locked], cg2.main, cg3.main]
merge completion fiber will try to stop cg0'.main, which will be
blocked on compaction lock. which is held by the reenabler in
_compaction_reenablers_for_merging, hence deadlock.
The fix is to wait for background merge to finish before we start the
next merge. It's achieved by holding old erm in the background merge,
and doing a topology barrier from the merge finalizing transition.
Background merge is supposed to be a relatively quick operation, it's
stopping compaction groups. So may wait for active requests. It
shouldn't prolong the barrier indefinitely.
Tablet boost unit tests which trigger merge need to be adjusted to
call the barrier, otherwise they will be vulnerable to the deadlock.
Two cluster tests were removed because they assumed that merge happens
in the backgournd. Now that it happens as part of merge finalization,
and blocks topology state machine, those tests deadlock because they
are unable to make topology changes (node bootstrap) while background
merge is blocked.
The test "test_tablets_merge_waits_for_lwt" needed to be adjusted. It
assumed that merge finalization doesn't wait for the erm held by the
LWT operation, and triggered tablet movement afterwards, and assumed
that this migration will issue a barrier which will block on the LWT
operation. After this commit, it's the barrier in merge finalization
which is blocked. The test was adjusted to use an earlier log mark
when waiting for "Got raft_topology_cmd::barrier_and_drain", which
will catch the barrier in merge finalization.
Fixes SCYLLADB-928
Needs to be ordered before split finalization, because storage_group
must be in split mode already at finalization time. There must be
split-ready compaction groups, otherwise finalization fails with this
error:
Found 0 split ready compaction groups, but expected 2 instead.
Exposed by increased split activity in tests.
can_use_effective_service_level_cache() always returns true now, so the function can be dropped entirely and all the code that assumes it may return false can be dropped as well. Also drop async versions of find_effective_service_level and get_user_scheduling_group since they are unused.
No need to backport, code removal,
Closesscylladb/scylladb#29002
* github.com:scylladb/scylladb:
service level: make maybe_update_per_service_level_params synchronous
service level: remove unused get_user_scheduling_group function
service level: drop async find_effective_service_level
service level: remove remnants of version 1 service level
This PR shortens two sleeps from 1s to 100ms to speed up bootstrap in tests.
The changed sleeps are:
- the pause duration in group0 discovery,
- the retry period in `wait_for_cql`.
Refs: https://scylladb.atlassian.net/browse/SCYLLADB-918
No backport: performance improvements mostly relevant to tests.
Closesscylladb/scylladb#29020
* github.com:scylladb/scylladb:
test: pylib: util: wait for CQL being ready with a shorter period
group0: discovery: shorten the pause duration
Add basic cluster tests for CQL forwarding.
The test cases include:
- basic reads and writes
- prepared statements with binds
- forwarding from a non-replica
- exception passthrough during forwarding (using an injection)
- re-preparing a statement on the target node, even if the user
query is also an EXECUTE request on a prepared statement
- verification metric updates
The existing test_basic_write_read was modified so that a few extra
cases could be validated on the same cluster.
We enable CQL forwarding by starting to return the bounce_to_node
result message in redirect_statement() instead of throwing. The
forwarding code introduced in the preceding patches reacts to these
messages, allowing the requests to be forwarded.
With the update, some tests assuming that requests can't be forwarded
need to be adjusted, so we do that as well.
Use rolling_max_tracker to record gross bytes allocated during each
CQL parse. The rolling maximum is then added to the memory estimate
for incoming QUERY and PREPARE requests so that the admission control
in the CQL transport layer accounts for parsing overhead.
The measured memory footprint serves as upper bound rather than
exact number but it's purpose is to prevent OOMs under unprepared
statements heavy load.
In benchmark 1G memory node shows decrease of non-LSA memory usage
from peak 320MB (our coordinator budget is 10% of 1G) to 96MB. While
tps drops from 1.2 kops to 0.8 kops. Drop in tps is expected as
memory admission kicks in trying to prevent OOM.
This is phase 1 of OOM prevention, potential next steps:
- add second admission in query_processor::get_statement trying to prevent potential thundering herd problem
- decrease cql_server memory pool size
- count reads in the memory pool
- add per service level memory pool and a shared one
Related https://scylladb.atlassian.net/browse/SCYLLADB-740
Fixes https://scylladb.atlassian.net/browse/SCYLLADB-938
Backport: no, new feature, but we may reconsider if some customer needs it
Closesscylladb/scylladb#28919
* github.com:scylladb/scylladb:
cql3: track CQL parsing memory cost and use it for admission control
utils: add rolling max tracker
