RowCache misses Updates ----------------------- Key: CASSANDRA-3862 URL: https://issues.apache.org/jira/browse/CASSANDRA-3862 Project: Cassandra Issue Type: Bug Components: Core Affects Versions: 1.0.7 Reporter: Daniel Doubleday
While performing stress tests to find any race problems for CASSANDRA-2864 I guess I (re-)found one for the standard on-heap row cache. During my stress test I hava lots of threads running with some of them only reading other writing and re-reading the value. This seems to happen: - Reader tries to read row A for the first time doing a getTopLevelColumns - Row A which is not in the cache yet is updated by Writer. The row is not eagerly read during write (because we want fast writes) so the writer cannot perform a cache update - Reader puts the row in the cache which is now missing the update I already asked this some time ago on the mailing list but unfortunately didn't dig after I got no answer since I assumed that I just missed something. In a way I still do but haven't found any locking mechanism that makes sure that this should not happen. The problem can be reproduced with every run of my stress test. When I restart the server the expected column is there. It's just missing from the cache. To test I have created a patch that merges memtables with the row cache. With the patch the problem is gone. I can also reproduce in 0.8. Haven't checked 1.1 but I haven't found any relevant change their either so I assume the same aplies there. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira