[
https://issues.apache.org/jira/browse/CASSANDRA-5937?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13752457#comment-13752457
]
Chris Burroughs commented on CASSANDRA-5937:
--------------------------------------------
Ryan's graphs and tooling looked really good so I was hopping he could quickly
catch something I missed. But anyway I've narrowed the "regression" down to
CASSANDRA-5939.
> check read performance between 1.2.5 and 1.2.8
> ----------------------------------------------
>
> Key: CASSANDRA-5937
> URL: https://issues.apache.org/jira/browse/CASSANDRA-5937
> Project: Cassandra
> Issue Type: Test
> Reporter: Chris Burroughs
> Assignee: Ryan McGuire
> Priority: Minor
>
> We upgraded from 1.2.5 to 1.2.8 on 08-02 and saw a significant increase in
> read latency:
> * median: < 1ms to > 1ms
> * 75p: ~ 1 ms to > 3.5 ms
> * 95p: ~ 3 ms to ~ 8 ms
> Cluster is a 2 DC cluster with about 20 nodes per DC (using
> GossipingPropertyFileSnitch). All queries are for one Keyspace filled with
> skinny rows so we have Row cache enabled and the Key cache disabled. The row
> cache hit is close to 70%, which makes the magnitude of the new median/75th
> hard to understand.
> I have not been able to demonstrate a regression with stress on either a
> single or dozen node cluster. For internal reasons invovling client side
> problem we have not tried rolling back so I'm not positive it's a cassandra
> code problem (as opposed to something else we did/configured).
> Thanks for checking it out!
--
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
