[Spice-devel] changing the timing of spice client linking in migration (RHBZ #725009)

[Yonit Halperin]

On 08/25/2011 01:53 PM, Gerd Hoffmann wrote:
> I've played with a approach simliar to (2) long ago.  Actually did it by
> registering a "live" migration handler.  Didn't work that well too.
> spice client will stay connected to both source and target for a long
> time, and the spice code base simply couldn't handle that very well. One
> problem was a timeout somewhere which was *way* to short.  Second was
> that some stuff such as new connects are blocked in that "migration"
> state.  Doesn't hurt much if that lasts a second or two, but for a few
> minutes it isn't acceptable.  Maybe there was more which I don't remember.

If we can't connect to the target during migration, this means the "not 
seamless" solution is problematic as well, and we may need ==> a libvirt 
change <== :
We need to connect to the target before migration starts. We can either 
do it upon client_migrate_info, under the assumption that the target is 
already up and that it is called just before migration.
Or otherwise, we need to introduce a new command from libvirt, just 
before migration, with the same assumptions.

Regarding the timeout: do you remember if it occured on the server 
display_channel? It is a timeout, but it shouldn't be triggered with the 
seamless migration path...

Yonit.