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https://issues.apache.org/jira/browse/CASSANDRA-1123?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13443229#comment-13443229
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David Alves commented on CASSANDRA-1123:
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maybe I'm missing something, but I think we're covered:
- since the responsibility of logging such an event would always fall on the
writing thread my point was that any log event generated by that thread would
already go to all appenders but the tracing one because the TL state doen't get
propagated there (for instance if we used try/catch in runMayThrow).
- CassandraDaemon already sets a default exception handler that logs to error.
- The only thing that is not done is the
test-whether-exception-handler-is-set-and-if-not-log dance that DTPE does but
since one such handler is set this shouldn't be a problem, correct?
All this being said nothing like making sure by testing. will post back.
> Allow tracing query details
> ---------------------------
>
> Key: CASSANDRA-1123
> URL: https://issues.apache.org/jira/browse/CASSANDRA-1123
> Project: Cassandra
> Issue Type: New Feature
> Components: Core
> Reporter: Jonathan Ellis
> Assignee: David Alves
> Fix For: 1.2.0 beta 1
>
> Attachments: 1123-3.patch.gz, 1123.patch, 1123.patch, 1123.patch,
> 1123.patch, 1123-v6.txt, 1123-v7.patch
>
>
> In the spirit of CASSANDRA-511, it would be useful to tracing on queries to
> see where latency is coming from: how long did row cache lookup take? key
> search in the index? merging the data from the sstables? etc.
> The main difference vs setting debug logging is that debug logging is too big
> of a hammer; by turning on the flood of logging for everyone, you actually
> distort the information you're looking for. This would be something you
> could set per-query (or more likely per connection).
> We don't need to be as sophisticated as the techniques discussed in the
> following papers but they are interesting reading:
> http://research.google.com/pubs/pub36356.html
> http://www.usenix.org/events/osdi04/tech/full_papers/barham/barham_html/
> http://www.usenix.org/event/nsdi07/tech/fonseca.html
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