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From hive13 Wong <hiv...@gmail.com>
Subject Re: single node capacity
Date Thu, 10 Jun 2010 13:44:30 GMT
You are right, our write traffic indeed is pretty tense as we are now at the
stage of initializing data.
Then we do need some more nodes here.

Thanks very much Martin.

On Thu, Jun 10, 2010 at 9:04 PM, Dr. Martin Grabm├╝ller <
Martin.Grabmueller@eleven.de> wrote:

>  Your problem is probably not the amount of data you store, but the number
> of
> SSTable files.  When these increase, read latency goes up.  Write latency
> maybe
> goes up because of compaction.  Check in the data directory, whether there
> are many
> data files, and check via JMX whether compaction is happening.
>
> My recommendation is to reduce the write traffic to the nodes so that each
> node can
> keep up with compaction.  If reducing the load is not possible, you have to
> add nodes
> (or get faster hard disks, but that is often not possible).
>
> Martin
>
>  ------------------------------
> *From:* hive13 Wong [mailto:hive13@gmail.com]
> *Sent:* Thursday, June 10, 2010 2:58 PM
> *To:* user@cassandra.apache.org
> *Subject:* single node capacity
>
> Hi,
>
> How much data load can a single typical cassandra instance handle?
> It seems like we are getting into trouble when one of our node's load grows
> to bigger than 200g. Both read latency and write latency are increasing,
> varying from 10 to several thousand milliseconds.
> machine config is 16*cpu 32G RAM
> Heap size is 10G
> Any suggestion of tuning?
> Or should I start considering adding more nodes when the data grows to this
> big?
>
> Thanks
>
>

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