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From Jabbar Azam <aja...@gmail.com>
Subject Re: Any experience of 20 node mini-itx cassandra cluster
Date Tue, 16 Apr 2013 21:29:57 GMT
I already have thanks. I'll do the tests with the hardware arrives.

Thanks

Jabbar Azam


On 16 April 2013 22:27, aaron morton <aaron@thelastpickle.com> wrote:

> Can't we use LCS?
>
> Do some reading and some tests…
>
> http://www.datastax.com/dev/blog/leveled-compaction-in-apache-cassandra
> http://www.datastax.com/dev/blog/when-to-use-leveled-compaction
>
> Cheers
>
> -----------------
> Aaron Morton
> Freelance Cassandra Consultant
> New Zealand
>
> @aaronmorton
> http://www.thelastpickle.com
>
> On 15/04/2013, at 10:44 PM, Jabbar Azam <ajazam@gmail.com> wrote:
>
> I know the SSD's are a bit small but they should be enough for our
> application. Out test data is 1.6 TB(including replication of rf=3). Can't
> we use LCS? This will give us more space at the expensive of more I/O but
> SSD's have loads of I/Os.
>
>
>
>
>
> Thanks
>
> Jabbar Azam
>
>
> On 14 April 2013 20:20, Jabbar Azam <ajazam@gmail.com> wrote:
>
>> 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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