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Posted to user@cassandra.apache.org by Radim Kolar <hs...@sendmail.cz> on 2011/11/09 11:08:17 UTC
max_compaction_threshold
I found in stress tests that default setting this to 32 is way too high.
Hadoop guys are using value 10 during merge sorts to not stress IO that
much. I also discovered that filesystems like ZFS are using default io
queue size of 10 per drive.
I tried run tests with 10, 15 and 32 and there is very little
improvement 15 over 10, but 32 is performance drop. Test is simply
create lot of 5m sstables by diabling minor compactions and then set it
back and measure time elapsed.
Re: max_compaction_threshold
Posted by Radim Kolar <hs...@sendmail.cz>.
i consulted with hadoop expert and he told me that he is using value 100
for merging segments. I will rerun tests with 100 to check.