At the end of the test, we wait until a restarted node receives a
snapshot from the leader, and then verify that the log has been
truncated.
To check the snapshot, the test used the `system.raft_snapshots` table,
while the log is stored in `system.raft`.
Unfortunately, the two tables are not updated atomically when Raft
persists a snapshot (scylladb/scylladb#9603). We first update
`system.raft_snapshots`, then `system.raft` (see
`raft_sys_table_storage::store_snapshot_descriptor`). So after the wait
finishes, there's no guarantee the log has been truncated yet -- there's
a race between the test's last check and Scylla doing that last delete.
But we can check the snapshot using `system.raft` instead of
`system.raft_snapshots`, as `system.raft` has the latest ID. And since
1640f83fdc, storing that ID and truncating
the log in `system.raft` happens atomically.
Closes scylladb/scylladb#17106
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++ cql-pytest - 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.