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https://issues.apache.org/jira/browse/HBASE-29222?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Nick Dimiduk resolved HBASE-29222.
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Resolution: Fixed
Pushed to branch-2.6+. Thanks [~bewing]!
> Avoid expensive tracing calls if tracing is disabled
> ----------------------------------------------------
>
> Key: HBASE-29222
> URL: https://issues.apache.org/jira/browse/HBASE-29222
> Project: HBase
> Issue Type: Improvement
> Affects Versions: 3.0.0-beta-1, 2.5.11, 2.6.2
> Reporter: Becker Ewing
> Assignee: Becker Ewing
> Priority: Major
> Labels: pull-request-available
> Fix For: 2.7.0, 3.0.0-beta-2, 2.6.3
>
> Attachments: slow-decompressor-reinit.2.html
>
>
> Building off of https://issues.apache.org/jira/browse/HBASE-29099—where we
> removed certain expensive calls if tracing was disabled—it appears that there
> is more opportunities to avoid allocating/recording trace metadata if we can
> determine that a trace is disabled.
> This is inspired by a glance at the first flamegraph in
> https://issues.apache.org/jira/browse/HBASE-29218 where we spent an aggregate
> 1.48% of all CPU time in OpenTelemetry calls (I filtered for "io/opentelem").
> Given that tracing is an opt-in feature, we ideally shouldn't impose a
> performance penalty if it isn't enabled. Span Calls in the Block I/O Path
> (particularly those in BlockIOUtils & HFileBlock) look to dominate this
> flamegraph. We should ensure that we're only recording expensive attributes
> if tracing is enabled in those paths.
> As it stands now, BlockIOUtils#readWithExtra spends 40% of it's time in
> OpenTelemetry calls and the rest of it's time reading data from the
> filesystem which shows the non-trivial nature of the tracing context being
> recorded.
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