incubator-cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Edward Capriolo <>
Subject Re: compaction throughput rate not even close to 16MB
Date Wed, 24 Apr 2013 20:33:26 GMT
I have noticed the same. I think in the "real" world your compaction
throughput is limited by other things. If I had to speculate I would say
that compaction can remove expired tombstones, however doing this requires
bloom filter checks, etc.

I think that setting is more important with multi threaded compaction
and/or more compaction slots. In those cases it may actually throttle

On Wed, Apr 24, 2013 at 3:54 PM, Hiller, Dean <> wrote:

> I was wondering about the compactionthroughput.  I never see ours get even
> close to 16MB and I thought this is supposed to throttle compaction, right?
>  Ours is constantly less than 3MB/sec from looking at our logs or do I have
> this totally wrong?  How can I see the real throughput so that I can
> understand how to throttle it when I need to?
> 94,940,780 bytes to 95,346,024 (~100% of original) in 38,438ms =
> 2.365603MB/s.  2,350,114 total rows, 2,350,022 unique.  Row merge counts
> were {1:2349930, 2:92, }
> Thanks,
> Dean

View raw message