[CASSANDRA-9345] LeveledCompactionStrategy bad performance

• Type: Bug
• Status: Resolved
• Priority: Normal
• Resolution: Duplicate
• Labels: lcs
• Severity: Normal
• Assignee: Carl Yeksigian
• Reporter: Alan Boudreault

Authors

Carl Yeksigian

• Tester: Alan Boudreault
• Created: 11/May/15 18:10
• Updated: 16/Apr/19 09:31
• Resolved: 14/Oct/15 15:39

Description

--> This issue doesn't affect any release and is only reproducible in a dev branch

While working on CASSANDRA-7409, we noticed that there were some bad performance with LCS. It seems that the compaction is not triggered as it should. The performance is really bad when using low heap but we can also see that using a big heap there are something wrong with the number of compactions.

Here are the graphs that compare 2.1 vs the dev branch (Take care when visualizing the graphs, the y-axis scales differ due to some peaks):
http://dl.alanb.ca/perf/lcs-2.1-vs-trunk-LH.html
http://dl.alanb.ca/perf/lcs-2.1-vs-trunk-BH.html

I've attached the stress yaml config used for this test.

Issue Links

• duplicates: CASSANDRA-7409 Allow multiple overlapping sstables in L1
• is broken by: CASSANDRA-7409 Allow multiple overlapping sstables in L1