cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Jonathan Ellis (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (CASSANDRA-1123) Allow tracing query details
Date Mon, 27 Aug 2012 16:49:07 GMT

     [ https://issues.apache.org/jira/browse/CASSANDRA-1123?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Jonathan Ellis updated CASSANDRA-1123:
--------------------------------------

    Attachment: 1123-v6.txt

v6 attached.  adds trace session.finished_at, adds back debug logging for thrift methods when
tracing is off, removes probability from thrift interface.  

uses newTaskFor in DTPE, but overrides execute as well.  (otherwise we wrap, then newTaskFor
wraps a second time.  might as well just wrap once.)

TODO: exposing probability to nodetool.
                
> 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
>
>         Attachments: 1123-3.patch.gz, 1123.patch, 1123.patch, 1123.patch, 1123.patch,
1123-v6.txt
>
>
> 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

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

Mime
View raw message