c5dc086baf
The ANN vector queries with all-zero vectors are allowed even on vector indexes with similarity function set to cosine. When enabling the rescoring option, those queries would fail as the rescoring calls `similarity_cosine` function underneath, causing an `InvalidRequest` exception as all-zero vectors were not allowed matching Cassandra's behaviour. To eliminate the discrepancy we want the all-zero vector `similarity_cosine` calls to pass, but return the NaN as the cosine similarity for zero vectors is mathematically incorrect. We decided not to use arbitrary values contrary to USearch, for which the distance (not to be confused with similarity) is defined as cos(0, 0) = 0, cos(0, x) = 1 while supporting the range of values [0, 2]. If we wanted to convert that to similarity, that would mean sim_cos(0, x) = 0.5, which does not support mathematical reasoning why that would be more similar than for example vectors marking obtuse angles. It's safe to assume that all-zero vectors for cosine similarity shouldn't make any impact, therefore we return NaN and eliminate them from best results. Adjusted the tests accordingly to check both proper Cassandra and Scylla's behaviour. Fixes: SCYLLADB-456 Backport to 2026.1 needed, as it fixes the bug for ANN vector queries using rescoring introduced there. Closes scylladb/scylladb#28609 * github.com:scylladb/scylladb: test/vector_search: add reproducer for rescoring with zero vectors vector_search: return NaN for similarity_cosine with all-zero vectors
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.