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We have two mechanism to give visibility into reads having to process many tombstones: * a warning in the logs, triggered if a read processed more the `tombstone_warn_threshold` dead rows/tombstones * a trace message, which includes stats of the amount of rows in the page, including the amount of live and dead rows as well as tombstones This series extends this to also include information on cells, so we have visibility into the case where a read has to process an excessive amount of cell tombstones (mainly because of collections). A log line is now also logged if the amount of dead cells/tombstones in the page exceeds `tombstone_warn_threshold`. The trace message is also extended to contain cell stats. The `tombstone_warn_threshold` log lines now receive a 10s rate-limit to avoid excessive log spamming. The rate-limit is separate for the row and cell logs. Example of the new log line (`tombstone_warn_threshold=10` ): ``` WARN 2024-05-30 07:56:44,979 [shard 0:stmt] querier - Read 98 live cells and 126 dead cells/tombstones for system_schema.scylla_tables <partition-range-scan> (-inf, +inf) (see tombstone_warn_threshold) ``` Example of the new tracing message: ``` Page stats: 1 partition(s), 0 static row(s) (0 live, 0 dead), 1 clustering row(s) (1 live, 0 dead), 0 range tombstone(s) and 13 cell(s) (1 live, 12 dead) [shard 0] | 2024-05-30 08:13:19.690803 | 127.0.0.1 | 6114 | 127.0.0.1 ``` Fixes: https://github.com/scylladb/scylladb/issues/18996 Improvement, not a backport candidate. Closes scylladb/scylladb#18997 * github.com:scylladb/scylladb: test/boost: mutation_test: add test for cell compaction stats mutation/compact_and_expire_result: drop operator bool() querier: consume_page(): add rate-limiting to tombstone warnings querier: consume_page(): add cell stats to page stats trace message querier: consume_page(): add tombstone warning for cell tombstones querier: consume_page(): extract code which logs tombstone warning mutation/mutation_compactor: collect and aggregate cell compaction stats mutation: row::compact_and_expire(): use compact_and_expire_result collection_mutation: compact_and_expire(): use compact_and_expire_result mutation: introduce compact_and_expire_result
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.