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From Benjamin Black...@b3k.us>
Subject Re: 4k keyspaces... Maybe we're doing it wrong?
Date Mon, 06 Sep 2010 06:21:21 GMT
On Thu, Sep 2, 2010 at 6:25 PM, Mike Peters
<cassandra@softwareprojects.com> wrote:
>
> My concerns are -
> #1. Will every single node end up with 4k folders under /cassandra/data/?
>

Yes (and you should review how Cassandra works if that is a question for you).

> #2. Performance: Will Cassandra work better with a single keyspace + lots of
> keys, or thousands of keyspaces?
>

Thousands is a non-starter.  There is an active memtable for every CF
defined and caches (row and key) are per CF.  Assuming even 2 CFs per
keyspace,  with 4000 keyspaces you will have 8000 active memtables,
8000 _sets_ of sstables to be compacted, etc.  Put everyone in the
same keyspace, use a prefix on keys to distinguish different clients.


b

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