Last week in scylla.git master (issue #137; 2022-07-10)

[Avi Kivity]

This short report brings to light some interesting commits to scylla.git master from the last weeks. Commits in the 4fd289a78c..a7fa29bceb range are covered.

There were 83 non-merge commits from 15 authors in that period. Some notable commits:

Previously, and schema update caused a flush of all memtables containing schema information (i.e. in the system_schema keyspace). This made schema updates (e.g. ALTER TABLE) quite slow. This was because we could not ensure that commitlog replay of the schema update would come before the commitlog replay of changes that depend on it. Now, however, we have a separate commitlog domain that can be replayed before regular data mutations, and so we no longer flush schema update mutations, speeding up schema updates considerably.

The token() built-in function will now correctly return NULL if given NULL inputs, instead of failing the request.

Gossip convergence time in large clusters has been improved by disregarding frequently changing state that is not important to cluster topology - cache hit rate and view backlog statistics.

It is now possible to cap compaction I/O to a given throughput by setting the compaction_throughput_mb_per_sec option.

See you in the next issue of last week in scylla.git master!