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https://issues.apache.org/jira/browse/CASSANDRA-1123?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12976128#action_12976128
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Jonathan Ellis commented on CASSANDRA-1123:
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still looks like the simplest solution is to add a thrift
system_enable_query_details() method that would cause what we log at debug, to
be logged at INFO _for queries from that connection_. We'd need to add this to
the intra-cluster messages too, either as a part of the Message Header or (more
lightweight) as a bit in the header computed by MessagingService.packIt. (Up
until it hits MessagingService everything will be run on the same thread, so we
can use a threadlocal like we do for keyspace in CassandraServer.)
incidentally, i don't think we log anything about how many sstables are checked
on a per-query basis (although we collect this globally in a histogram), so
that would be good to add.
> 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: Brandon Williams
> Fix For: 0.8
>
>
> 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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