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From Shahryar Sedghi <shsed...@gmail.com>
Subject Re: Multiple keyspace question
Date Fri, 06 Jul 2012 20:15:19 GMT
Aaron

I am going to have many (over 50 eventually) keyspaces with limited number
of CFs (5-6) do you think this one can cause a problem too.

Thanks

On Fri, Jul 6, 2012 at 2:28 PM, aaron morton <aaron@thelastpickle.com>wrote:

> Also, all CF's in the same KS share one commit log. So all writes for the
> row row key, across all CF's, are committed at the same time.
>
> Some other settings, such as caches in 1.1, are machine wide.
>
> If you have a small KS for something like app config, I'd say go with
> whatever feels right. If you are talking about two full "application" KS's
> I would think about their prospective workloads and growth patterns. Will
> you always want to manage the two together ?
>
> Cheers
>
> -----------------
> Aaron Morton
> Freelance Developer
> @aaronmorton
> http://www.thelastpickle.com
>
> On 6/07/2012, at 9:47 PM, Robin Verlangen wrote:
>
> Hi Ben,
>
> The amount of keyspaces is not the problem: the amount of column families
> is. Each column family adds a certain amount of memory usage to the system.
> You can cope with this by adding memory or using generic column families
> that store different types of data.
>
> With kind regards,
>
> Robin Verlangen
> *Software engineer*
> *
> *
> W http://www.robinverlangen.nl
> E robin@us2.nl
>
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> 2012/7/6 Ben Kaehne <ben.kaehne@sirca.org.au>
>
>> Good evening,
>>
>> I have read multiple keyspaces are bad before in a few discussions, but
>> to what extent?
>>
>> We have some reasonably powerful machines and looking to host
>> an additional (currently we have 1) 2 keyspaces within our cassandra
>> cluster (of 3 nodes, using RF3).
>>
>> At what point does adding extra keyspaces start becoming an issue? Is
>> there anything special we should be considering or watching out for as we
>> implement this?
>>
>> I could not imagine that all cassandra users out there are running one
>> massive keyspace, and at the same time can not imaging that all cassandra
>> users have multiple clusters just to host different keyspaces.
>>
>> Regards.
>>
>> --
>> -Ben
>>
>
>
>
>


-- 
"Life is what happens while you are making other plans." ~ John Lennon

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