[jira] [Updated] (CASSANDRA-6591) un-deprecate cache recentHitRate and expose in o.a.c.metrics

["Chris Burroughs (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/CASSANDRA-6591?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Chris Burroughs updated CASSANDRA-6591:
---------------------------------------

    Attachment: j6591-1.2-v3.txt

New approach.  Doesn't really touch recentHitRate anymore

 * No more extra threads or polling recentHitRate
 * Meter added for misses
 * 1/5/15 minute hit rates calculated by hits/requests moving averages.  Everyone I have talked too says this is sound.

> un-deprecate cache recentHitRate and expose in o.a.c.metrics
> ------------------------------------------------------------
>
>                 Key: CASSANDRA-6591
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-6591
>             Project: Cassandra
>          Issue Type: Improvement
>          Components: Core
>            Reporter: Chris Burroughs
>            Assignee: Chris Burroughs
>            Priority: Minor
>         Attachments: j6591-1.2-v1.txt, j6591-1.2-v2.txt, j6591-1.2-v3.txt
>
>
> recentHitRate metrics were not added as part of CASSANDRA-4009 because there is not an obvious way to do it with the Metrics library.  Instead hitRate was added as an all time measurement since node restart.
> This does allow changes in cache rate (aka production performance problems)  to be detected.  Ideally there would be 1/5/15 moving averages for the hit rate, but I'm not sure how to calculate that.  Instead I propose updating recentHitRate on a fixed interval and exposing that as a Gauge.



--
This message was sent by Atlassian JIRA
(v6.1.5#6160)