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Jonathan Ellis commented on CASSANDRA-5939: ------------------------------------------- bq. we have removed CLHM in 2.0 Yup. The cost/benefit of spending time on CLHM just isn't there for me. Especially as the guy who argued we should remove row cache entirely. :) Unless you are planning to dig in, Chris, I propose we wontfix. > Cache Providers calculate very different row sizes > -------------------------------------------------- > > Key: CASSANDRA-5939 > URL: https://issues.apache.org/jira/browse/CASSANDRA-5939 > Project: Cassandra > Issue Type: Bug > Components: Core > Environment: 1.2.8 > Reporter: Chris Burroughs > Assignee: Vijay > > Took the same production node and bounced it 4 times comparing version and > cache provider. ConcurrentLinkedHashCacheProvider and > SerializingCacheProvider produce very different results resulting in an order > of magnitude difference in rows cached. In all cases the row cache size was > 2048 MB. Hit rate is provided for color, but entries & size are the > important part. > 1.2.8 ConcurrentLinkedHashCacheProvider: > * entries: 23,217 > * hit rate: 43% > * size: 2,147,398,344 > 1.2.8 about 20 minutes of SerializingCacheProvider: > * entries: 221,709 > * hit rate: 68% > * size: 18,417254 > 1.2.5 ConcurrentLinkedHashCacheProvider: > * entries: 25,967 > * hit rate: ~ 50% > * size: 2,147,421,704 > 1.2.5 about 20 minutes of SerializingCacheProvider: > * entries: 228,457 > * hit rate: ~ 70% > * size: 19,070,315 > A related(?) problem is that the ConcurrentLinkedHashCacheProvider sizes seem > to be highly variable. Digging up the values for 5 different nodes in the > cluster using ConcurrentLinkedHashCacheProvider shows a wide variance in > number of entries: > * 12k > * 444k > * 10k > * 25k > * 25k -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira