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From Terje Marthinussen <>
Subject Re: hw requirements
Date Wed, 31 Aug 2011 18:03:36 GMT
SSD's definitely makes live simpler as you will get a lot less trouble with impact from  things
like compactions.

Just beware that Cassandra expands data a lot due to storage overhead (for small columns),
replication and needed space for compactions and repairs. 

It is well worth doing some real life testing here before you order a lot of HW !

With our tuning and load, Java vm cannot really use more than 12GB for heap before GC falls
apart, so probably 24GB would be a nice memory size per server.

And yes, many small is better than a few large in most cases.


On Aug 31, 2011, at 10:27 AM, Maxim Potekhin wrote:

> Plenty of comments in this thread already, and I agree with those saying
> "it depends". From my experience, a cluster with 18 spindles total
> could not match the performance and throughput of our primary
> Oracle server which had 108 spindles. After we upgraded to SSD,
> things have definitely changed for the better, for Cassandra.
> Another thing is that if you plan to implement "composite indexes" by
> catenating column values into additional columns, that would constitute
> a "write" hence you'll need CPU. So watch out.
> On 8/29/2011 9:15 AM, Helder Oliveira wrote:
>> Hello guys,
>> What is the type of profile of a cassandra server.
>> Are SSD an option ?
>> Does cassandra needs better CPU ou lots of memory ?
>> Are SATA II disks ok ?
>> I am making some tests, and i started evaluating the possible hardware.
>> If someone already has conclusions about it, please share :D
>> Thanks a lot.

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