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https://issues.apache.org/jira/browse/CASSANDRA-7273?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14034080#comment-14034080
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Brandon Williams commented on CASSANDRA-7273:
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bq. I was trying to say that some metrics can be meaningless if combined
together. For example, 95%tile of global sstables per read can shadow certain
column family's high sstable read. Or bloom filter false positive ratio. If one
is high and the other is low, then the global average cannot tell certain CF
has low fp ratio. (Correct me if I'm wrong.)
This was my exact reasoning as well, but [[email protected]] convinced that
in practice, it actually was helpful. Keep in mind though this isn't an
average, just another histogram with totals.
bq. Also, there already node level latency metrics in StorageProxy, so I don't
feel the need for one in global CF.
SP latency is different from local latency though.
> expose global ColumnFamily metrics
> ----------------------------------
>
> Key: CASSANDRA-7273
> URL: https://issues.apache.org/jira/browse/CASSANDRA-7273
> Project: Cassandra
> Issue Type: New Feature
> Reporter: Richard Wagner
> Assignee: Brandon Williams
> Priority: Minor
> Labels: lhf
> Fix For: 1.2.17
>
> Attachments: 7273-2_1_branch-v1.txt
>
>
> It would be very useful to have cassandra expose ColumnFamily metrics that
> span all column families. A general purpose cassandra monitoring system built
> up around the current ColumnFamily metrics really only has a couple of
> choices right now: publish metrics for all column families or fetch metrics
> for all column families, aggregate them and then publish the aggregated
> metrics. The first can be quite expensive for the downstream monitoring
> system and the second is a piece of work that it seems is better pushed into
> cassandra itself.
> Perhaps these global ColumnFamily metrics could be published under a name of:
> org.apache.cassandra.metrics:type=(ColumnFamily|IndexColumnFamily),name=(Metric
> name)
> (Same as existing ColumnFamily metrics, but with no keyspace or scope.)
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