[ https://issues.apache.org/jira/browse/CASSANDRA-14261?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16377368#comment-16377368 ]
Jeff Jirsa commented on CASSANDRA-14261: ---------------------------------------- I don't, because I did them on a laptop on a plane over the holidays, and it's decidedly synthetic non-prod tests, but these looked simple and sufficiently isolated not to warrant a full run in perf. Here's an estimate from memory though: [this|https://github.com/jeffjirsa/cassandra/commit/b2b2d765c089c5be609d65f04611b2800ffa70b8] was based on seeing that function in the stack about 5% of the time in compaction, and it goes from 5% to ~0.001% with that trivial patch. [this|https://github.com/jeffjirsa/cassandra/commit/dc8070eaa5ec52e8be46358777fe42d9944f5f30] was based on seeing ~130MB of allocations (about 3.12% of the TLAB allocation for a 9 second span). And [this|https://github.com/jeffjirsa/cassandra/commit/391846e4d0cfd8c8076c3e6050fb0b13496e24ed] I expect to never show up in profiles except under very high contention, which I have little desire to manually test, but it should be fairly obvious to most people that it's both safe and necessary. > Compaction Profiling Improvements > --------------------------------- > > Key: CASSANDRA-14261 > URL: https://issues.apache.org/jira/browse/CASSANDRA-14261 > Project: Cassandra > Issue Type: Improvement > Components: Compaction > Reporter: Jeff Jirsa > Assignee: Jeff Jirsa > Priority: Minor > Fix For: 4.x > > > There's some low hanging fruit in some laptop compaction runs, such as > creating a ton of the same object unnecessarily and hashing cell names > repeatedly to see if a column is dropped even when we should know that the > table has no dropped columns. -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org For additional commands, e-mail: commits-h...@cassandra.apache.org