[Ocfs2-devel] ocfs2_controld.cman

[Joel Becker <Joel.Becker@oracle.com>]

On Thu, Apr 09, 2009 at 11:22:28AM -0500, David Teigland wrote:
> On Wed, Apr 08, 2009 at 03:22:37PM -0700, Joel Becker wrote:
> > > This isn't a correct assumption.  It's possible that two or more nodes
> > > joining at once will become initial members together.  (I realize that
> > > it's a very convenient assumption to make after using it in previous
> > > pre-cpg programs, and it may take a fair amount of work to do without.)
> > 
> > Well, this is going to be fun.  I have to figure out which daemon is
> > the "first", and now it's just racy.  I could swear that someone told
> > me cpg would guarantee i see the joins in order, not at the same time.
> 
> It may just work to have both race to create the checkpoint, the loser should
> get an error back from create (I haven't tried it, but I'd expect it to work
> that way.)

	If only OpenAIS wasn't so loose here.  If my daemon dies and
restarts, the checkpoints I previously created might not have gone away
yet.  So I get EEXIST for a short while until CKPT is done disposing of
them.  ocfs2_controld handles this, but it means we can't rely on
EEXIST.

Joel

-- 

"Baby, even the losers
 Get luck sometimes.
 Even the losers
 Keep a little bit of pride."

Joel Becker
Principal Software Developer
Oracle
E-mail: joel.becker at oracle.com
Phone: (650) 506-8127