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https://issues.apache.org/jira/browse/HBASE-15376?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15177354#comment-15177354
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stack commented on HBASE-15376:
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Sounds good by me. If it just 'broke', no need to bring it along . Just release
note it.
> ScanNext metric is size-based while every other per-operation metric is time
> based
> ----------------------------------------------------------------------------------
>
> Key: HBASE-15376
> URL: https://issues.apache.org/jira/browse/HBASE-15376
> Project: HBase
> Issue Type: Sub-task
> Reporter: Enis Soztutar
> Attachments: HBASE-15376.patch, HBASE-15376_v1.patch
>
>
> We have per-operation metrics for {{Get}}, {{Mutate}}, {{Delete}},
> {{Increment}}, and {{ScanNext}}.
> The metrics are emitted like:
> {code}
> "Get_num_ops" : 4837505,
> "Get_min" : 0,
> "Get_max" : 296,
> "Get_mean" : 0.2934618155433431,
> "Get_median" : 0.0,
> "Get_75th_percentile" : 0.0,
> "Get_95th_percentile" : 1.0,
> "Get_99th_percentile" : 1.0,
> ...
> "ScanNext_num_ops" : 194705,
> "ScanNext_min" : 0,
> "ScanNext_max" : 18441,
> "ScanNext_mean" : 7468.274651395701,
> "ScanNext_median" : 583.0,
> "ScanNext_75th_percentile" : 583.0,
> "ScanNext_95th_percentile" : 13481.0,
> "ScanNext_99th_percentile" : 13481.0,
> {code}
> The problem is that all of Get,Mutate,Delete,Increment,Append,Replay are time
> based tracking how long the operation ran, while ScanNext is tracking
> returned response sizes (returned cell-sizes to be exact). Obviously, this is
> very confusing and you would only know this subtlety if you read the metrics
> collection code.
> Not sure how useful is the ScanNext metric as it is today. We can deprecate
> it, and introduce a time based one to keep track of scan request latencies.
> ps. Shamelessly using the parent jira (since these seem relavant).
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