> Also, there are plenty of > compactions running - it just seems like the number of pending tasks > is never affected. Is there ever a time when the pending count is non zero but nodetool compactionstats does not show any running tasks ?
If compaction cannot keep up you may be generating data faster than LCS can compact it. What sort of disks do you have? What is the min_sstable_size ? The old default was 5, the new one is 130. The higher value will result in less IO. Cheers ----------------- Aaron Morton New Zealand @aaronmorton Co-Founder & Principal Consultant Apache Cassandra Consulting http://www.thelastpickle.com On 24/10/2013, at 3:16 AM, Russ Garrett <r...@garrett.co.uk> wrote: > On 23 October 2013 15:05, Michael Theroux <mthero...@yahoo.com> wrote: >> When we made a similar move, for an unknown reason (I didn't hear any >> feedback from the list when I asked why this might be), compaction didn't >> start after we moved from SizedTiered to leveled compaction until I ran >> "nodetool compact <keyspace> <column-family-converted-to-lcs>". > > Yup, I understand that's this issue (the fix is still unreleased): > https://issues.apache.org/jira/browse/CASSANDRA-6092 > > However, my suspicion is that adding/removing nodes has probably > kickstarted the compaction anyway. I've tried issuing "nodetool > compact" with no obvious improvement. Also, there are plenty of > compactions running - it just seems like the number of pending tasks > is never affected. > > Good point on the version. I'm on 2.0.1. > > -- > Russ Garrett > r...@garrett.co.uk
