Data directories

[Héctor Izquierdo Seliva <iz...@strands.com>]

Hi,

Is there a way to control what sstables go to what data directory? I
have a fast but space limited ssd, and a way slower raid, and i'd like
to put latency sensitive data into the ssd and leave the other data in
the raid. Is this possible? If not, how well does cassandra play with
symlinks?

Re: Data directories

[Héctor Izquierdo Seliva <iz...@strands.com>]

I'm actually using it in a couple of nodes, but is slower than directly
accesing the data in a ssd.

El jue, 09-06-2011 a las 11:10 -0400, Chris Burroughs escribió:
> On 06/08/2011 05:54 AM, Héctor Izquierdo Seliva wrote:
> > Is there a way to control what sstables go to what data directory? I
> > have a fast but space limited ssd, and a way slower raid, and i'd like
> > to put latency sensitive data into the ssd and leave the other data in
> > the raid. Is this possible? If not, how well does cassandra play with
> > symlinks?
> > 
> 
> Another option would be to use the ssd as a block level cache with
> something like flashcache <https://github.com/facebook/flashcache/>.

Re: Data directories

[Chris Burroughs <ch...@gmail.com>]

On 06/08/2011 05:54 AM, Héctor Izquierdo Seliva wrote:
> Is there a way to control what sstables go to what data directory? I
> have a fast but space limited ssd, and a way slower raid, and i'd like
> to put latency sensitive data into the ssd and leave the other data in
> the raid. Is this possible? If not, how well does cassandra play with
> symlinks?
> 

Another option would be to use the ssd as a block level cache with
something like flashcache <https://github.com/facebook/flashcache/>.

Re: Data directories

[Héctor Izquierdo Seliva <iz...@strands.com>]

El mié, 08-06-2011 a las 08:42 -0500, Jonathan Ellis escribió:
> No. https://issues.apache.org/jira/browse/CASSANDRA-2749 is open to
> track this but nobody is working on it to my knowledge.
> 
> Cassandra is fine with symlinks at the data directory level but I
> don't think that helps you, since you really want to move the sstables
> themselves. (Cassandra is NOT fine with symlinked sstable files, or
> with any moving around of sstable files while it is running.)

I was planing on creating another keyspace and moving the slow sstables
there. Of course everything done while the node is stopped.

Thanks for your help

Re: Data directories

[Jonathan Ellis <jb...@gmail.com>]

No. https://issues.apache.org/jira/browse/CASSANDRA-2749 is open to
track this but nobody is working on it to my knowledge.

Cassandra is fine with symlinks at the data directory level but I
don't think that helps you, since you really want to move the sstables
themselves. (Cassandra is NOT fine with symlinked sstable files, or
with any moving around of sstable files while it is running.)

2011/6/8 Héctor Izquierdo Seliva <iz...@strands.com>:
>
> Hi,
>
> Is there a way to control what sstables go to what data directory? I
> have a fast but space limited ssd, and a way slower raid, and i'd like
> to put latency sensitive data into the ssd and leave the other data in
> the raid. Is this possible? If not, how well does cassandra play with
> symlinks?
>
>



-- 
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of DataStax, the source for professional Cassandra support
http://www.datastax.com