f604269f0a
When a table has secondary indexes on *multiple* columns, and several such columns are used for filtering in a query, Scylla chooses one of these indexes as the main driver of the query, and the second column's restriction is implemented as filtering. Before this patch, the index to use was chosen fairly randomly, based on the order of the indexes in the schema. This order may be different in different coordinators, and may even change across restarts on the same coordinators. This is not only inconsistent, it can cause outright wrong results when using *paging* and switching (or restarting) coordinates in the middle of a paged scan... One coordinator saves one index's key in the paging state, and then the other coordinator gets this paging state and wrongly believes it is supposed to be a key of a *different* index. The fix in this patch is to pick the index suitable for the first indexed column mentioned in the query. This has two benefits over the situation before the patch: 1. The decision of which index to use no longer changes between coordinators or across restarts - it just depends on the schema and the specific query. 2. Different indexes can have different "specificity" so using one or the other can change the query's performance. After this patch, the user is in control over which index is used by changing the order of terms in the query. A curious user can use tracing to check which index was used to implement a particular query. An xfailing test we had for this issue no longer fails, so the "xfail" marker is removed. Fixes #7969 Signed-off-by: Nadav Har'El <nyh@scylladb.com> Closes scylladb/scylladb#14450
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.