Re: [Qemu-devel] [PATCH COLO-Frame (Base) v21 12/17] COLO: Add 'x-colo-lost-heartbeat' command to trigger failover

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Amit Shah (amit.shah@redhat.com) wrote:
> On (Tue) 18 Oct 2016 [20:10:08], zhanghailiang wrote:
> > We leave users to choose whatever heartbeat solution they want,
> > if the heartbeat is lost, or other errors they detect, they can use
> > experimental command 'x_colo_lost_heartbeat' to tell COLO to do failover,
> > COLO will do operations accordingly.
> > 
> > For example, if the command is sent to the PVM, the Primary side will
> > exit COLO mode and take over operation.
> 
> Primary should already be in control, so there's nothing special
> needed to 'take over operation'?  At max, it should not do periodic
> syncs anymore till it hears from a (new) secondary.

But it has to stop waiting for an ack from the secondary, and stop sending
copies of block data to it etc.

Dave

> > If sent to the Secondary, the
> > secondary will run failover work, then take over server operation to
> > become the new Primary.
> > 
> > Cc: Luiz Capitulino <lcapitulino@redhat.com>
> > Cc: Eric Blake <eblake@redhat.com>
> > Cc: Markus Armbruster <armbru@redhat.com>
> > Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
> > Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
> > Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> 
> Reviewed-by: Amit Shah <amit.shah@redhat.com>
> 
> 
> 		Amit
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK