cleanup / move

[David McNelis <dm...@agentisenergy.com>]

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.*

Re: cleanup / move

[aaron morton <aa...@thelastpickle.com>]

>  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.
> 
>