Files
scylladb/test
Raphael S. Carvalho c77f710a0c sstables: Fix quadratic space complexity in partitioned_sstable_set
Interval map is very susceptible to quadratic space behavior when
it's flooded with many entries overlapping all (or most of)
intervals, since each such entry will have presence on all
intervals it overlaps with.

A trigger we observed was memtable flush storm, which creates many
small "L0" sstables that spans roughly the entire token range.

Since we cannot rely on insertion order, solution will be about
storing sstables with such wide ranges in a vector (unleveled).

There should be no consequence for single-key reads, since upper
layer applies an additional filtering based on token of key being
queried.
And for range scans, there can be an increase in memory usage,
but not significant because the sstables span an wide range and
would have been selected in the combined reader if the range of
scan overlaps with them.

Anyway, this is a protection against storm of memtable flushes
and shouldn't be the common scenario.

It works both with tablets and vnodes, by adjusting the token
range spanned by compaction group accordingly.

Fixes #23634.

Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
2025-04-29 15:47:33 -03:00
..
2024-11-06 16:48:36 +02:00

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.