Repeated lookup operation returns different results
Repeated calls to at least 2 different REST calls returned
different results.
Calls were .../space/memories/category and
.../space/attributes/cp=type&v=*
Also tested using only the java api with the same behavior.
Rebooting the cluster seemed to resolve the issue. The
hypothesis is that it is some kind of caching issue.
Demonstrated problem to Jim.
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2 Posted by Kyle Nakamoto on 12 Mar, 2010 09:07 PM
The data for this space was ingested solely with the REST interface. We are using a 3 machine cluster for this case. Saffron version 8.0.0-1784
Support Staff 3 Posted by Jim Fleming on 12 Mar, 2010 09:32 PM
Submitted to development.
Support Staff 4 Posted by Jim Fleming on 14 Mar, 2010 01:31 PM
Kyle, Is this reproducible? If so, can you turn on your MySQL general query log so we can see the queries being issued?
see: http://dev.mysql.com/doc/refman/5.1/en/query-log.html for more information.
Thanks,
Jim
Support Staff 5 Posted by Jim Fleming on 15 Mar, 2010 01:22 PM
Kyle, We also have a page on MySQL logging:
http://docs.saffronsierra.com/MySQL-Logging
If you see the problem again, you can make the change to the MySQL configuration, then run:
creset -r
to restart MySQL. You should then be able to run the REST query and see what queries MySQL is receiving. We are trying to reproduce here, but if you are able to reproduce first it would be good to see that log.
Thanks,
Jim
Support Staff 6 Posted by Jim Fleming on 16 Mar, 2010 06:42 PM
Kyle, Unfortunately we cannot reset MySQL (with a new config) once the cluster has been started, so I would recommend that you try turn on the general query log for MySQL and then immediately try and reproduce the problem. The general query log tends to grow pretty quickly, and there are scripts that you can run to rotate them if you feel inclined, see:
http://themattreid.com/wordpress/?p=34
However, your best bet may be to try and reproduce first. If it doesn't work, you can think about using the script to maybe delete the log nightly, for example.
Lets start with logging the head node and use a wild-card query, so that it is broadcasted to all nodes. Follow the steps here and add the line:
log
to /etc/my.cnf on the head node. Restart MySQL via creset -r and you should be good. If you see the problem, you can tail the log: /var/run/mysqld/mysqld.log. Let me know if you have any questions.
Thanks,
Jim
Support Staff 7 Posted by Jim Fleming on 04 May, 2010 07:03 PM
Issue has been resolved.
Jim Fleming resolved this discussion on 04 May, 2010 07:03 PM.