[ovs-dev] requirements for xapi hooks to replace ovs-xenserverd polling

[Ian Campbell]

On Thu, 2010-05-06 at 21:17 +0100, Ben Pfaff wrote: 
> On Wed, May 05, 2010 at 06:56:25PM +0100, Ian Campbell wrote:
> > I am looking at adding some hooks (implemented as scripts
> > in /etc/xapi.d/$EVENT) to remove the need for polling from
> > ovs-xenserverd to detect pool join and eject events and am wondering
> > what your actual needs are. You can see my first cut and some further
> > comments at
> > http://lists.xensource.com/archives/html/xen-api/2010-05/msg00007.html
> 
> In general, what OVS needs is to know when network UUIDs change, because
> it announces those UUIDs through its configuration database.  I think
> that means that it needs to hook post-join and post-eject.  *But* your
> email implies that pool ejection always requires a reboot[*].  If that's
> the case, then OVS does not need to use a post-eject hook, because it
> always re-queries the network UUIDs at boot time anyhow (in
> interface-reconfigure).
> 
> [*] Please forgive my ignorance on that matter; I don't know actually
>     know whether that is correct.

Thanks Ben.

Yes, pool eject always implies a reboot, AFAIK.

Does that mean you only actually need a join hook?

Ian.