[jira] [Commented] (CASSANDRA-12876) Negative mean write latency

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

    [ https://issues.apache.org/jira/browse/CASSANDRA-12876?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15633349#comment-15633349 ] 

Chris Lohfink commented on CASSANDRA-12876:
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I am certain this is related to CASSANDRA-11752 and its 30 min rescaling. if you access the values() of the histogram directly you wont see this for what its worth

> Negative mean write latency
> ---------------------------
>
>                 Key: CASSANDRA-12876
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-12876
>             Project: Cassandra
>          Issue Type: Bug
>          Components: Observability
>            Reporter: Kévin LOVATO
>         Attachments: negative_mean.png, negative_mean_periodicity.PNG
>
>
> The mean write latency returned by JMX turns negative every 30 minutes. As the attached screenshots show, the value turns negative every 30 minutes after the startup of the node.
> We did not experience this behavior in 2.1.16.



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