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From Jonathan Ellis <jbel...@gmail.com>
Subject Re: Weird problem with empty CF
Date Wed, 28 Sep 2011 22:22:03 GMT
Sounds like you have non-expired tombstones.

http://wiki.apache.org/cassandra/DistributedDeletes

On Wed, Sep 28, 2011 at 12:35 PM, Daning <daning@netseer.com> wrote:
> I have an app polling a few CFs (select first N * from CF), there were data
> in CFs but later were deleted so CFs were empty for a long time. I found
> Cassandra CPU usage was getting high to 80%, normally it uses less than 30%.
> I issued the select query manually and feel the response is slow. I have
> tried nodetool compact/repair for those CFs but that does not work. later, I
> issue 'truncate' for all the CFs and CPU usage gets down to 1%.
>
> Can somebody explain to me why I need to truncate an empty CF? and what else
> I could do to bring the CPU usage down?
>
> I am running 0.8.6.
>
> Thanks,
>
> Daning
>
>



-- 
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of DataStax, the source for professional Cassandra support
http://www.datastax.com

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