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Per Otterström commented on CASSANDRA-11752: -------------------------------------------- Yes, I would like to give it a try. Had a talk with [~cnlwsu] about it on NGCC. The idea is to create a separate DecayingEH implementation based on forward decay. > histograms/metrics in 2.2 do not appear recency biased > ------------------------------------------------------ > > Key: CASSANDRA-11752 > URL: https://issues.apache.org/jira/browse/CASSANDRA-11752 > Project: Cassandra > Issue Type: Bug > Components: Core > Reporter: Chris Burroughs > Labels: metrics > Attachments: boost-metrics.png, c-jconsole-comparison.png, > c-metrics.png, default-histogram.png > > > In addition to upgrading to metrics3, CASSANDRA-5657 switched to using a > custom histogram implementation. After upgrading to Cassandra 2.2 > histograms/timer metrics are not suspiciously flat. To be useful for > graphing and alerting metrics need to be biased towards recent events. > I have attached images that I think illustrate this. > * The first two are a comparison between latency observed by a C* 2.2 (us) > cluster shoring very flat lines and a client (using metrics 2.2.0, ms) > showing server performance problems. We can't rule out with total certainty > that something else isn't the cause (that's why we measure from both the > client & server) but they very rarely disagree. > * The 3rd image compares jconsole viewing of metrics on a 2.2 and 2.1 > cluster over several minutes. Not a single digit changed on the 2.2 cluster. -- This message was sent by Atlassian JIRA (v6.3.4#6332)