Thank you Robert and others for answering my questions.

I started to play with nodetool  and I have few more questions.

Does nodetool cleanup run synchronously or asynchronously ?

If it is running asynchronously is there any way to monitor the progress ?

Thank you
Emalayan


From: Robert Coli <rcoli@eventbrite.com>
To: user@cassandra.apache.org; Emalayan Vairavanathan <svemalayan@yahoo.com>
Sent: Thursday, 20 June 2013 10:03 AM
Subject: Re: [Cassandra] Running node tool cleanup

On Thu, Jun 20, 2013 at 12:01 AM, Emalayan Vairavanathan
<svemalayan@yahoo.com> wrote:
> 1) What will happen if I run nodetool cleanup immediately after bringing a
> new node up (i.e. before the key migration process is completed) ?
>        Will it cause some race conditions ? Or will it result in some part
> of the space never be reclaimed ?

As I understand it, the new node isn't responsible for the range until
the migration process is complete, so I presume cleanup will do
nothing in this case. This is so the old node can continue to serve
the range during the bootstrap, and in case of bootstrap failure.

> 2) After adding a new machine, how can I make sure that the key migration is
> completed ? Should I run nodetool netstats on all the nodes ? Is there any
> better way ?

nodetool ring/netstats and/or grepping the log for the
completed-bootstrap message.

=Rob