> -----Original Message-----
> From: Lukas Straub [mailto:lukasstra...@web.de]
> Sent: Friday, August 16, 2019 3:48 AM
> To: Dr. David Alan Gilbert <dgilb...@redhat.com>
> Cc: qemu-devel <qemu-devel@nongnu.org>; Zhang, Chen
> <chen.zh...@intel.com>; Jason Wang <jasow...@redhat.com>; Xie
> Changlong <xiechanglon...@gmail.com>; Wen Congyang
> <wencongya...@huawei.com>
> Subject: Re: [Qemu-devel] [PATCH v2 0/3] colo: Add support for continious
> replication
>
> On Thu, 15 Aug 2019 19:57:37 +0100
> "Dr. David Alan Gilbert" <dgilb...@redhat.com> wrote:
>
> > * Lukas Straub (lukasstra...@web.de) wrote:
> > > Hello Everyone,
> > > These Patches add support for continious replication to colo.
> > > Please review.
> >
> >
> > OK, for those who haven't followed COLO for so long; 'continuous
> > replication' is when after the first primary fails, you can promote
> > the original secondary to a new primary and start replicating again;
> >
> > i.e. current COLO gives you
> >
> > p<->s
> > <primary fails>
> > s
> >
> > with your patches you can do
> >
> > s becomes p2
> > p2<->s2
> >
> > and you're back to being resilient again.
> >
> > Which is great; because that was always an important missing piece.
> >
> > Do you have some test scripts/setup for this - it would be great to
> > automate some testing.
>
> My Plan is to write a Pacemaker Resource Agent[1] for qemu-colo and then do
> some long-term testing in my small cluster here. Writing standalone tests
> using
> that Resource Agent should be easy, it just needs to be provided with the
> right
> arguments and environment Variables.
Thanks Dave's explanation.
It looks good for me and I will test this series in my side.
Another question: Is "Pacemaker Resource Agent[1] " like a heartbeat module?
I have wrote an internal heartbeat module running on Qemu, it make COLO can
detect fail and trigger failover automatically, no need external APP to call
the QMP command "x-colo-lost-heartbeat". If you need it, I can send a RFC
version recently.
Thanks
Zhang Chen
>
> Regards,
> Lukas Straub
>
> [1] https://github.com/ClusterLabs/resource-agents/blob/master/doc/dev-
> guides/ra-dev-guide.asc#what-is-a-resource-agent
