From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=43291 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OGwcK-00004q-8l for qemu-devel@nongnu.org; Tue, 25 May 2010 12:04:35 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OGwc9-0008VC-Bv for qemu-devel@nongnu.org; Tue, 25 May 2010 12:04:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55474) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OGwc9-0008Ur-3f for qemu-devel@nongnu.org; Tue, 25 May 2010 12:04:21 -0400 Date: Tue, 25 May 2010 17:04:16 +0100 From: "Daniel P. Berrange" Subject: Re: [Qemu-devel] Re: [PATCH 3/5] QMP: Introduce MIGRATION events Message-ID: <20100525160416.GP31759@redhat.com> References: <9b6575587d22a5c85ec536172810520ee3b945d5.1274796992.git.quintela@redhat.com> <4BFBE843.5070202@codemonkey.ws> <4BFBF36D.8070208@codemonkey.ws> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4BFBF36D.8070208@codemonkey.ws> Reply-To: "Daniel P. Berrange" List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori Cc: qemu-devel@nongnu.org, Juan Quintela On Tue, May 25, 2010 at 10:57:33AM -0500, Anthony Liguori wrote: > On 05/25/2010 10:35 AM, Juan Quintela wrote: > >Anthony Liguori wrote: > > > > > >> > >>>+Data: None > >>>+ > >>>+Example: > >>>+ > >>>+{ "event": "MIGRATION_CANCELED", > >>>+ "timestamp": {"seconds": 1274687575, "microseconds": 592483} } > >>>+ > >>>+MIGRATION_ENDED > >>>+--------------- > >>>+ > >>>+Emitted when migration ends (both in source and target) > >>> > >>> > >>A start event is going to be generated already, no? > >> > >problem here is that libvirt start target with -S, and waits to do the > >"cont" as soon as possible. As of know, only way to do it is to poll > >info migrate on source faster. > > > > Why does it do that?? > > That sound like a terrible idea. Historically QEMU gave no alternative. Adding these STARTED/ENDED events is to allow libvirt to detect start + end of migration reliably, avoiding the previous hacks QEMU forced us todo on the dest, and avoid the high rate polling we had no choice but todo on the source. > >>I think this makes more sense as a MIGRATION_CONNECTED event. It > >>probably should carry peer information too. > >> > >What kind of peer information? > > > >We have tcp/fd/exec/unix migrations. calling it CONNECTED vs STARTED, I > >don't care. But adding information? Notice that the management > >application knows what it did, I can put the: > > > > "exec: gzip -d< /tmp/foo" > > > >string, but not much more that I can put here. > > Basically, do we have any useful information in info migrate that we can > include? info migrate just includes the progress info + state (running, finished, cancelled, failed). The event itself replicates state. I don't see a hugely compelling need to include the progress info in the FINISHED/CANCELLED events. If really needed, the app can still call 'info migrate' to get it. Regards, Daniel -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://deltacloud.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|