c63f43975f
This patch adds a reproducer for an Alternator Streams bug described in issue #28439, where the stream returns the wrong events (and fewer of them) in the following specific combination of the following circumstances: 1. A BatchWriteItem operation writing multiple items to the *same* partition. 2. The "always_use_lwt" write isolation mode is used. (the bug doesn't occur in other write isolation modes). We didn't catch this bug earlier because the Alternator Streams test we had for BatchWriteItem had multiple items in multiple partitions, and we missed the multiple-items-in-one-partition case. Moreover, today we run all the tests in only_rmw_uses_lwt mode (in the past, we did use always_use_lwt, but changed recently in commite7257b1393following commit76a766cthat changed test.py). As issue #28439 explains, the underlying cause of the bug is that the always_use_lwt causes the multiple items to be written with the same timestamp, which confused the Alternator Streams code reading the CDC log. The bug is not in BatchWriteItem itself, or in ScyllaDB CDC, but just in the Alternator Streams layer. The test in this patch is parameterized to run on each of the four write isolation modes, and currently fails (and so marked xfail) just for the one mode 'always_use_lwt'. The test is scylla_only, as its purpose is to checks the different write isolation mode - which don't exist in AWS DynamoDB. Refs #28439 Signed-off-by: Nadav Har'El <nyh@scylladb.com>
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.