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From rohit bhatia <rohit2...@gmail.com>
Subject Re: Local read/write vs write request
Date Wed, 11 Jul 2012 15:39:26 GMT
The requests are clearly balanced.. But the data is not

Do all nodes have the similar token range ownership?
Are you using a randomPartitioner or an OrderPreserving partitioner?

On Wed, Jul 11, 2012 at 7:29 PM, Olivier Mallassi <omallassi@octo.com>wrote:

> Hi all
>
> During our load tests, we observe that a couple of servers are much more
> used than others (in terms of CPU). In front of the cassandra cluster we
> have a IPVS (ipvsadm configured in rr)
>
> in opscenter we have the following graph :
> Write / read Request : almost evenly distributed ...
> [image: Inline image 1]
>
> Local Writes / Read Request : clearly not evenly distributed and as you
> can imagine, the high loaded nodes (in CPU) are the ones with more TPS....
> [image: Inline image 2]
>
>
> Based on that, my best idea is that load tests we are doing use data that
> is physically located on a couple of server (bad luck....).
>
> We tried using different data (in our load tests), so different key but
> the behavior seem identical (we will repeat the tests).
>
> Do you have any ideas of what can be wrong?
>
> thx a lot.
>
> --
> ............................................................
> Olivier Mallassi
> OCTO Technology
> ............................................................
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> 75008 Paris
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>

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