Re: [libvirt] [PATCH] Introduce yet another migration version in API.
On Tue, Nov 02, 2010 at 01:08:53PM +0000, Daniel P. Berrange wrote:
This patch attempts to introduce a version 3 that uses the
improved 5 step sequence
* Src: Begin
- Generate XML to pass to dst
- Generate optional cookie to pass to dst
* Dst: Prepare
- Get ready to accept incoming VM
- Generate optional cookie to pass to src
* Src: Perform
- Start migration and wait for send completion
- Generate optional cookie to pass to dst
* Dst: Finish
- Wait for recv completion and check status
- Kill off VM if failed, resume if success
- Generate optional cookie to pass to src
* Src: Confirm
- Kill off VM if success, resume if failed
What happens if no confirmation is recieved (destination silently died)?
Will there be a timeout (bad idea), or at least a means by which higher
level management can cancel migration?
Either way, I did not get the suggestion to contact divinity.
+ /*
+ * If Perform3 indicated an error, or if NULL was returned
+ * from Finish3, then the status code tells the source
+ * to resume CPUs on the original VM.
+ */
+ ret = domain->conn->driver->domainMigrateConfirm3
+ (domain->conn, dname, cookiesrc, cookiesrclen, cookiedst, cookiedstlen,
+ uri, flags, ret >= 0 && domain ? 0 : -1);
+ /* XXX is there anything we can do if Confirm3 returns -1.
+ * Probably nothing beyond praying
+ */