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https://issues.apache.org/jira/browse/CASSANDRA-7731?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14150805#comment-14150805
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Jeremiah Jordan commented on CASSANDRA-7731:
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This ticket is about displaying the max value reported by metrics in nodetool.
Not about the calculation of that value. Changing how the metrics themselves
work is to be done in other tickets previously mentioned.
> Get max values for live/tombstone cells per slice
> -------------------------------------------------
>
> Key: CASSANDRA-7731
> URL: https://issues.apache.org/jira/browse/CASSANDRA-7731
> Project: Cassandra
> Issue Type: Improvement
> Components: Core
> Reporter: Cyril Scetbon
> Assignee: Robert Stupp
> Priority: Minor
> Fix For: 2.1.1
>
> Attachments: 7731-2.0.txt, 7731-2.1.txt
>
>
> I think you should not say that slice statistics are valid for the [last five
> minutes
> |https://github.com/apache/cassandra/blob/cassandra-2.0/src/java/org/apache/cassandra/tools/NodeCmd.java#L955-L956]
> in CFSTATS command of nodetool. I've read the documentation from yammer for
> Histograms and there is no way to force values to expire after x minutes
> except by
> [clearing|http://grepcode.com/file/repo1.maven.org/maven2/com.yammer.metrics/metrics-core/2.1.2/com/yammer/metrics/core/Histogram.java#96]
> it . The only thing I can see is that the last snapshot used to provide the
> median (or whatever you'd used instead) value is based on 1028 values.
> I think we should also be able to detect that some requests are accessing a
> lot of live/tombstone cells per query and that's not possible for now without
> activating DEBUG for SliceQueryFilter for example and by tweaking the
> threshold. Currently as nodetool cfstats returns the median if a low part of
> the queries are scanning a lot of live/tombstone cells we miss it !
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