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From Tupshin Harper <tups...@tupshin.com>
Subject Re: impact of update operation to read operation
Date Mon, 10 Feb 2014 21:18:17 GMT
You don't mention disks and RAM,  but I would assume that the additional
data meant that you could now cache a lower percentage and that you have to
seek on disk more often.

-Tupshin
On Feb 10, 2014 4:14 PM, "Jiaan Zeng" <l.allen09@gmail.com> wrote:

> Hi All,
>
> I am using Cassandra 1.2.4. I wonder if update operation has
> *permanent* impacts on read operation. Below is the scenario.
>
> Previously, a read only workload runs against one column family and
> has 4000 qps. Later, a read-update mixed workload  runs against the
> same column family. After that, the read only workload runs again but
> it could not get 4000 qps, only get 3500 qps. After a manual major
> compaction is issued through command line, the read only workload gets
> 3600 qps which seems to tell major compaction does not help much.
>
> Did anyone have similar experiences? Any idea why this is happening?
> Thanks.
>
> --
> Regards,
> Jiaan
>

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