> - Cassandra log reports 12,955,585 of them have been saved on the last save > events. Has their been much activity between saves ?
Nothing jumps out. There is a setting for the max entries to store, but this only applies to the row cache. Can you reproduce issue in a dev environment ? When running the key cache holds keys of the form <SSTable, DecoratedKey> so there is an entry for each SSTable the key appears in. When saved only the DecoratedKey's are stored, and the key cache is rebuilt on startup when iterating over the index files. e.g. ig you have 12 entries in the keycache, it may only be 4 unique keys and that is all that is written when saving the cache. From a quick look at the code it looks like the code is writing all DecoratedKeys , not just the unique ones. This may be mucking up the reported numbers, I'll take a look later. If you can reproduce it simply it would help. Cheers ----------------- Aaron Morton Freelance Developer @aaronmorton http://www.thelastpickle.com On 25/04/2012, at 1:11 AM, Omid Aladini wrote: > Hi, > > I'm experiencing losing a part of key cache on restart on Cassandra 1.0.7. > For example: > > - cfstats reports key cache size of 13,040,502 with capacity of 15,000,000. > - Cassandra log reports 12,955,585 of them have been saved on the last save > events. > - On restart Cassandra reads saved cache. > - cfstats reports key cache size of only 2,833,586 with correct capacity of > 15,000,000. > > There is no sign that the cache size is reduced due to memory pressure. The > key cache capacity is set manually via cassandra-cli. > > Has anyone else encountered this problem or is it a known issue? > > Thanks, > Omid
