nodetool drain disables writes?

[Anthony Molinaro <an...@alumni.caltech.edu>]

Hi,

  I thought that 'nodetool drain' was supposed to flush the commit logs
through the system, which it appears to do (verified by running ls in
the commit log directory and seeing no files).

However, it also appears to disable writes completely (ie, scripts attempting
to write data were frozen, ls of commit log directory showed no files), is
that expected behavior?

Is that command documented anywhere on the wiki?

Thanks,

-Anthony

-- 
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Anthony Molinaro                           <an...@alumni.caltech.edu>

Re: nodetool drain disables writes?

[Jonathan Ellis <jb...@gmail.com>]

On Tue, May 11, 2010 at 4:18 PM, Anthony Molinaro
<an...@alumni.caltech.edu> wrote:
> Hi,
>
>  I thought that 'nodetool drain' was supposed to flush the commit logs
> through the system, which it appears to do (verified by running ls in
> the commit log directory and seeing no files).
>
> However, it also appears to disable writes completely (ie, scripts attempting
> to write data were frozen, ls of commit log directory showed no files), is
> that expected behavior?

Yes.  The intent is that after the drain your commitlog is empty (e.g.
for upgrading to 0.7).  If it were to continue to accept writes that
would not be the case.

If you just want a flush, run `nodetool flush`.

-- 
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of Riptano, the source for professional Cassandra support
http://riptano.com