Files
scylladb/test
Michał Jadwiszczak e5d82bf857 test: fix flaky test_create_index_synchronous_updates trace event race
The test_create_index_synchronous_updates test in test_secondary_index_properties.py
was intermittently failing with 'assert found_wanted_trace' because the expected
trace event 'Forcing ... view update to be synchronous' was missing from the
trace events returned by get_query_trace().

Root cause: trace events are written asynchronously to system_traces.events.
The Python driver's populate() method considers a trace complete once the
session row in system_traces.sessions has duration IS NOT NULL, then reads
events exactly once. Since the session row and event rows are written as
separate mutations with no transactional guarantee, the driver can read an
incomplete set of events.

Evidence from the failed CI run logs:
- The entire test (CREATE TABLE through DROP TABLE) completed in ~300ms
  (01:38:54,859 - 01:38:55,157)
- The INSERT with tracing happened in a ~50ms window between the second
  CREATE INDEX completing (01:38:55,108) and DROP TABLE starting
  (01:38:55,157)
- The 'Forcing ... synchronous' trace message is generated during the
  INSERT write path (db/view/view.cc:2061), so it was produced, but
  not yet flushed to system_traces.events when the driver read them
- This matches the known limitation documented in test/alternator/
  test_tracing.py: 'we have no way to know whether the tracing events
  returned is the entire trace'

Fix: replace the single-shot trace.events read with a retry loop that
directly queries system_traces.events until the expected event appears
(with a 30s timeout). Use ConsistencyLevel.ONE since system_traces has
RF=2 and cqlpy tests run on a single-node cluster.

The same race condition pattern exists in test_mv_synchronous_updates in
test_materialized_view.py (which this test was modeled after), so the
same fix is proactively applied there as well.

Fixes SCYLLADB-1314

Closes scylladb/scylladb#29374

(cherry picked from commit 568f20396a)

Closes scylladb/scylladb#29395
2026-04-12 14:32:31 +03:00
..

Scylla in-source tests.

For details on how to run the tests, see docs/dev/testing.md

Shared C++ utils, libraries are in lib/, for Python - pylib/

alternator - Python tests which connect to a single server and use the DynamoDB API unit, boost, raft - unit tests in C++ cqlpy - Python tests which connect to a single server and use CQL topology* - tests that set up clusters and add/remove nodes cql - approval tests that use CQL and pre-recorded output rest_api - tests for Scylla REST API Port 9000 scylla-gdb - tests for scylla-gdb.py helper script nodetool - tests for C++ implementation of nodetool

If you can use an existing folder, consider adding your test to it. New folders should be used for new large categories/subsystems, or when the test environment is significantly different from some existing suite, e.g. you plan to start scylladb with different configuration, and you intend to add many tests and would like them to reuse an existing Scylla cluster (clusters can be reused for tests within the same folder).

To add a new folder, create a new directory, and then copy & edit its suite.ini.