[Openais] Re: confchg_fn, cluster membership, etc.

[Steven Dake]

On Thu, 2004-09-16 at 13:25, Mark Haverkamp wrote:
> On Thu, 2004-09-16 at 11:51, Steven Dake wrote:
> 
> > 
> > Not evs plugin, its really a plug to stop new high/med/low messages for
> > the group messaging (gmi).
> 
> Oh :-)

> > 
> > Here is how it works.  There are three interfaces added to gmi:
> > int gmi_recovery_plug_create (
> >     gmi_recovery_plug_handle *handle_recovery);
> > 
> > int gmi_recvoery_plug_destroy (
> >     gmi_recovery_plug_handle handle_recovery);
> > 
> > int gmi_recovery_plug_unplug (
> >     gmi_recovery_plug_handle handle_recovery);
> > 
> > 
> > In a service's aisexec_init_fn, gmi_recovery_plug_create is called if
> > the service doesn't want low/med/high priority messages to be sent by
> > any service until it has finished recovering its state (not messages).
> > 
> > Then after recovery of the service has completed, the service calls
> > gmi_recovery_plug_unplug.
> > 
> > A bitmap will be added to the token representing positions in the
> > memb_list that have been unplugged.  Once the bitmap has all positions
> > set for all members, high/med/low priority messages may be sent.  If the
> > bitmap is not completely set, then no high/med/low messages may be
> > sent.  After a regular configuration change, the bitmap will be set to
> > zero in the token.
> > 
> > A bitmap position is set by the processor once all handles that have
> > registered with gmi_recovery_plug_create have executed a
> > gmi_recovery_plug_unplug after the configuration change.
> 
> Does that mean that I can send messages GMI_PRIO_RECOVERY during this
> time?
> 

Yup that is the purpose, to only allow GMI_PRIO_RECOVERY messages so
other lower priority messages don't use up bandwidth or corrupt the
distributed states.

> Mark.
> 
> > 
> > Regards,
> > -steve
> > 
> > > Mark.