> 1) Is there any implication in running nodetool repair immediately after > bringing a new node up (before key migration process is completed) ? > Will it cause some race conditions ? Or will it result in some part > of the space never be reclaimed ? Repair will only be concerned with data that the node is replica for. And cleanup is only concerned with data that the node is no longer a replica for. AFAIK they should be able to run concurrently, but I would avoid it incase there are some edge cases.
> 2) How can I figure out the status of key migration in Cassandra? Not sure what you mean by key migration. If you are talking about a token move or node bootstrap you can get some idea from nodetool compactionstats and nodetool netstats. FWIW I think nodetool cleanup is less aggressive than repair. Repair reads all the data and creates a hash, cleanup just reads it from one file and writes a new file dropping rows that no longer belong. It's probably uses less CPU than compaction as it does not merge row fragments. Cheers ----------------- Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 19/06/2013, at 10:48 AM, Emalayan Vairavanathan <svemala...@yahoo.com> wrote: > Thank you all. > > I have two more question. > > 1) Is there any implication in running nodetool repair immediately after > bringing a new node up (before key migration process is completed) ? > Will it cause some race conditions ? Or will it result in some part > of the space never be reclaimed ? > > 2) How can I figure out the status of key migration in Cassandra? > > Thank you > Emalayan > > From: Richard Low <rich...@wentnet.com> > To: user@cassandra.apache.org; Emalayan Vairavanathan <svemala...@yahoo.com> > Sent: Tuesday, 18 June 2013 12:11 AM > Subject: Re: [Cassandra] Expanding a Cassandra cluster > > On 10 June 2013 22:00, Emalayan Vairavanathan <svemala...@yahoo.com> wrote: > > b) Will Cassandra automatically take care of removing > obsolete keys in future ? > > In a future version Cassandra should automatically clean up for you: > > https://issues.apache.org/jira/browse/CASSANDRA-5051 > > Right now though you have to run cleanup eventually or the space will never > be reclaimed. > > Richard. > >
