[Cluster-devel] cman init rework

[David Teigland]

On Tue, Mar 31, 2009 at 07:23:15AM +0200, Fabio M. Di Nitto wrote:
> On Mon, 2009-03-30 at 16:42 -0500, David Teigland wrote:
> > On Thu, Mar 26, 2009 at 02:50:31PM +0100, Fabio M. Di Nitto wrote:
> > > In our current startup sequence, we do start a daemon, we make sure it
> > > starts, but we never check if it's actually working properly.
> > 
> > If there's no groupd_compat setting in cluster.conf, or if it's set to 2, then
> > groupd does compat "detection" when it starts up, looking for old cluster2
> > nodes that require compat mode.  This detection phase can sometimes take a
> > while.  Other daemons have to ask groupd about the mode it chose after the
> > detection phase, and retry for a while if it's still pending.  It might be
> > nice for the init script to wait for this detection phase to complete after
> > starting groupd.  To do this we can run 'group_tool compat' and loop until
> > "pending" doesn't show up in a grep.  We should probably loop for somewhere
> > around 10 seconds, there's no good predictable number.  If groupd is still
> > pending after that time, the init script should just continue since it's most
> > likely taking longer than expected.  Other daemons are already prepared to
> > wait for groupd to pick a mode during their startup.
> 
> So far we specifically check for groupd_compat=0 to avoid starting
> groupd at all.
> 
> Is this still correct?
> 
> For other values of groupd_compat or none specified in the config, we
> start groupd.
> 
> Should we wait no matter what or only when none or 2 are specified?

Only when none or 2 are specified, there's no detection when set to 0 or 1.