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 <aja...@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" <edlinuxg...@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 <aja...@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 <cblo...@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) > >
