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From Andras Szerdahelyi <andras.szerdahe...@ignitionone.com>
Subject Re: key cache size in mb = 0 doesn't work?
Date Tue, 27 Nov 2012 04:06:27 GMT

SSTables in http://en.wikipedia.org/wiki/Page_cache maybe?
How many rows do you have in this CF? Are you getting all columns?

What do the cassandra.db mbeans say ( hit ratio, cache requests, items etc )

regards,
Andras

On 27 Nov 2012, at 04:12, Yiming Sun <yiming.sun@gmail.com> wrote:

> Hi,
> 
> I am carrying out some performance test against a 6-node cassandra cluster (v1.1.0),
and need to disable the key cache entirely as one of the scenarios.
> 
> However, by setting key_cache_size_in_mb to 0, I am still seeing caching effects.  For
example, when I fetch a set of 5000 rows, the first time it would deliver at about 60MB/sec,
but all subsequent fetches (even after fetching several other sets), it would deliver at about
120MB/sec.  This is exactly the same behavior I have observed when the key_cache_size_in_mb
was left blank.
> 
> So I am just wondering how I can disable the key cache entirely.  All our nodes have
JNA.jar deployed -- not sure it this has anything to do with what I saw.  Thanks.
> 
> -- Y


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