We run it concurrently each RF nodes (If RF = 3, we run it on 3 waves). If the node is busy cleaning up, then the client will time out and ask to an other node having a copy of the data and that is not being cleaned up.
"Will node tool cleanup consume lot of IO and CPU even though there is nothing to clean" Yes, I think so, since you have to check that you have nothing to clean... I think there is no case that need a regular cleanup anyway. 2013/6/12 Michal Michalski <mich...@opera.com> > What will happen if I add nodetool cleanup to run periodically (similar >> to nodetool repair) ? Will node tool cleanup consume lot of IO and CPU even >> though there is nothing to clean ? >> > > Why would you need doing so? > > M. > > > >> Thank you >> Emalayan >> >> >> ______________________________**__ >> From: Robert Coli <rc...@eventbrite.com> >> To: user@cassandra.apache.org; Emalayan Vairavanathan < >> svemala...@yahoo.com> >> Sent: Monday, 10 June 2013 5:15 PM >> Subject: Re: [Cassandra] Expanding a Cassandra cluster >> >> >> On Mon, Jun 10, 2013 at 3:13 PM, Emalayan Vairavanathan >> <svemala...@yahoo.com> wrote: >> >>> I suspect that nodetool cleanup is IO intensive. So running nodetool >>> cleanup >>> concurrently on the entire cluster may have a significantly impact the IO >>> performance of applications. >>> >> >> cleanup is a specific kind of compaction, and as such respects the >> compaction throughput throttle. >> >> The compaction throughput throttle is designed to prevent compaction >> from negatively impacting the performance of things-not-compaction. If >> you notice that cleanup compaction on all or most nodes consumes too >> much i/o, reduce the throttle value. >> >> =Rob >> >> >
