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From Jabbar Azam <aja...@gmail.com>
Subject Re: Any experience of 20 node mini-itx cassandra cluster
Date Sun, 14 Apr 2013 19:20:41 GMT
Thanks Aaron.

Thanks

Jabbar Azam


On 14 April 2013 19:39, aaron morton <aaron@thelastpickle.com> wrote:

> That's better.
>
> The SSD size is a bit small, and be warned that you will want to leave
> 50Gb to 100GB free to allow room for compaction (using the default size
> tiered).
>
> On the ram side you will want to run about 4GB (assuming cass 1.2) for the
> JVM the rest can be off heap Cassandra structures. This may not leave too
> much free space for the os page cache, but SSD may help there.
>
> Cheers
>
> -----------------
> Aaron Morton
> Freelance Cassandra Consultant
> New Zealand
>
> @aaronmorton
> http://www.thelastpickle.com
>
> On 13/04/2013, at 4:47 PM, Jabbar Azam <ajazam@gmail.com> wrote:
>
> What about using quad core athlon x4 740 3.2 GHz with 8gb of ram and 256gb
> ssds?
>
> I know it will depend on our workload but will be better than a dual core
> CPU. I think....
>
> Jabbar Azam
> On 13 Apr 2013 01:05, "Edward Capriolo" <edlinuxguru@gmail.com> wrote:
>
>> Duel core not the greatest you might run into GC issues before you run
>> out of IO from your ssd devices. Also cassandra has other concurrency
>> settings that are tuned roughly around the number of processors/cores. It
>> is not uncommon to see 4-6 cores of cpu (600 % in top dealing with young
>> gen garbage managing lots of sockets whatever.
>>
>>
>> On Fri, Apr 12, 2013 at 12:02 PM, Jabbar Azam <ajazam@gmail.com> wrote:
>>
>>> That's my guess. My colleague is still looking at CPU's so I'm hoping he
>>> can get quad core CPU's for the servers.
>>>
>>> Thanks
>>>
>>> Jabbar Azam
>>>
>>>
>>> On 12 April 2013 16:48, Colin Blower <cblower@barracuda.com> wrote:
>>>
>>>>  If you have not seen it already, checkout the Netflix blog post on
>>>> their performance testing of AWS SSD instances.
>>>>
>>>>
>>>> http://techblog.netflix.com/2012/07/benchmarking-high-performance-io-with.html
>>>>
>>>> My guess, based on very little experience, is that you will be CPU
>>>> bound.
>>>>
>>>>
>>>> On 04/12/2013 03:05 AM, Jabbar Azam wrote:
>>>>
>>>>   Hello,
>>>>
>>>>  I'm going to be building a 20 node cassandra cluster in one
>>>> datacentre. The spec of the servers will roughly be dual core Celeron CPU,
>>>> 256 GB SSD, 16GB RAM and two nics.
>>>>
>>>>
>>>>  Has anybody done any performance testing with this setup or have any
>>>> gotcha's I should be aware of wrt to the hardware?
>>>>
>>>>  I do realise the CPU is fairly low computational power but I'm going
>>>> to assume the system is going to be IO bound hence the RAM and SSD's.
>>>>
>>>>
>>>>  Thanks
>>>>
>>>> Jabbar Azam
>>>>
>>>>
>>>>
>>>> --
>>>>  *Colin Blower*
>>>> *Software Engineer*
>>>> Barracuda Networks Inc.
>>>> +1 408-342-5576 (o)
>>>>
>>>
>>>
>>
>

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