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https://issues.apache.org/jira/browse/CASSANDRA-7061?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13975618#comment-13975618
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Benedict commented on CASSANDRA-7061:
-------------------------------------
It is possible this may boil down to optimising the current tracing, supporting
a nanos mode and having configurable storage to reduce the overhead.
> High accuracy, low overhead local read/write tracing
> ----------------------------------------------------
>
> Key: CASSANDRA-7061
> URL: https://issues.apache.org/jira/browse/CASSANDRA-7061
> Project: Cassandra
> Issue Type: Improvement
> Components: Core
> Reporter: Benedict
> Assignee: Benedict
> Fix For: 3.0
>
>
> External profilers are pretty inadequate for getting accurate information at
> the granularity we're working at: tracing is too high overhead, so measures
> something completely different, and sampling suffers from bias of attribution
> due to the way the stack traces are retrieved. Hyperthreading can make this
> even worse.
> I propose to introduce an extremely low overhead tracing feature that must be
> enabled with a system property that will trace operations within the node
> only, so that we can perform various accurate low level analyses of
> performance. This information will include threading info, so that we can
> trace hand off delays and actual active time spent processing an operation.
> With the property disabled there will be no increased burden of tracing,
> however I hope to keep the total trace burden to less than one microsecond,
> and any single trace command to a few tens of nanos.
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