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Posted to user@cassandra.apache.org by Helder Oliveira <he...@byside.com> on 2011/08/29 15:15:28 UTC
hw requirements
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.
Re: hw requirements
Posted by Richard Low <rl...@acunu.com>.
Hi,
The hardware you choose depends a bit on your workload - writes vs
reads, amount of cacheable data, latency requirements, etc.. What
sort of workload do you expect?
See http://wiki.apache.org/cassandra/CassandraHardware for some general advice.
People typically have 8-24 GB RAM per node with 1-8 TB of storage, but
there are cases where bigger or smaller makes sense. Don't overspec
your nodes - you'll be better off with more smaller nodes.
You can use SSDs if you need the random read rate, and SATA drives are fine too.
--
Richard Low
Acunu | http://www.acunu.com | @acunu
On Mon, Aug 29, 2011 at 2:15 PM, Helder Oliveira
<he...@byside.com> 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.
>
Re: hw requirements
Posted by Terje Marthinussen <tm...@gmail.com>.
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.
Terje
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.
>
Re: hw requirements
Posted by Maxim Potekhin <po...@bnl.gov>.
Sorry about unclear naming scheme. I meant that if I want to index on a
few columns simultaneously,
I create a new column with catenated values of these.
On 8/31/2011 3:10 PM, Anthony Ikeda wrote:
> Sorry to fork this topic, but in "composite indexes" do you mean as
> strings or as "Composite()". I only ask cause we have started using
> the Composite as rowkeys and column names to replace the use of
> concatenated strings mainly for lookup purposes.
>
> Anthony
>
>
> On Wed, Aug 31, 2011 at 10:27 AM, Maxim Potekhin <potekhin@bnl.gov
> <ma...@bnl.gov>> 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.
>
>
>
Re: hw requirements
Posted by Anthony Ikeda <an...@gmail.com>.
Sorry to fork this topic, but in "composite indexes" do you mean as strings
or as "Composite()". I only ask cause we have started using the Composite as
rowkeys and column names to replace the use of concatenated strings mainly
for lookup purposes.
Anthony
On Wed, Aug 31, 2011 at 10:27 AM, Maxim Potekhin <po...@bnl.gov> 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.
>>
>
>
Re: hw requirements
Posted by Maxim Potekhin <po...@bnl.gov>.
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.