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From sankalp kohli <kohlisank...@gmail.com>
Subject Re: High-read latency for non-existing rows with LCS and 1.2.5
Date Thu, 27 Jun 2013 19:44:39 GMT
Try doing request tracing.
http://www.datastax.com/dev/blog/tracing-in-cassandra-1-2


On Thu, Jun 27, 2013 at 2:40 PM, Bao Le <lvqb@yahoo.com> wrote:

> Hi,
>
>     We are using Leveled Compaction with Cassandra 1.2.5. Our sstable size
> is 100M. On each node,
> we have anywhere from 700+ to 800+ sstables (for all levels). The
> bloom_filter_fp_chance is set at 0.000744.
>
>   For read requests that ask for existing row records, the latency is
> great, mostly under 20 milliseconds with key cache and row cache set. For
> read requests that ask for non-existing row records (not because of
> deletes, but rather, have never been in the system to start with), the
> latency is running into hundreds of milliseconds and sometimes seconds.
>
>   Just wonder if anyone has come across this before and has some pointers
> on how to reduce the latency in this case.
>
> Thanks
> Bao
>
>
>
>

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