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From aaron morton <aa...@thelastpickle.com>
Subject Re: cleanup / move
Date Tue, 13 Sep 2011 00:16:20 GMT
>  is there a techincal problem with running a nodetool move  on a node while a cleanup
is running?  
Cleanup is removing data that the node is no longer responsible for while move is first removing
*all* data from the node and then streaming new data to it. 

I'd put that in the crossing the streams category (http://www.youtube.com/watch?v=jyaLZHiJJnE).
i.e. best avoided. 

To kill the cleanup kill the node. Operations such as that create new data, and then delete
old data. They do not mutate existing data. 

Cleanup will write new SSTables, and then mark the old ones as compacted. When the old SSTables
are marked as compacted you should will see a zero length ".Compacted" file. Cassandra will
delete the compacted data files when it needs to. 

If you want the deletion to happen sooner rather than later force a Java GC through JConsole.


Hope that helps. 
 
-----------------
Aaron Morton
Freelance Cassandra Developer
@aaronmorton
http://www.thelastpickle.com

On 13/09/2011, at 7:41 AM, David McNelis wrote:

> While it would certainly be preferable to not run a cleanup and a move  at the same time
on the same node, is there a techincal problem with running a nodetool move  on a node while
a cleanup is running?  Or if its possible to gracefully kill a cleanup, so that a move can
 be run and then cleanup run after?
> 
> We have a node that is almost full and need to move it so that we can shift its  load....but
it already has a cleanup process running which, instead of causing less data usage as expected,
is  actually growing the amount of space taken at a pretty fast rate.
> 
> -- 
> David McNelis
> Lead Software Engineer
> Agentis Energy
> www.agentisenergy.com
> o: 630.359.6395
> c: 219.384.5143
> 
> A Smart Grid technology company focused on helping consumers of energy control an often
under-managed resource.
> 
> 


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