Re: [libvirt] [openstack-dev] [nova] The risk of hanging when shutdown instance.

On 03/30/2015 06:08 AM, Michal Privoznik wrote: > On 30.03.2015 11:28, zhang bo wrote: >> On 2015/3/28 18:06, Rui Chen wrote: >> >>> <snip/> >> >> The API virDomainShutdown's description is out of date, it's not correct. >> In fact, virDomainShutdown would block or not, depending on its mode. If it's in mode *agent*, then it would be blocked until qemu founds that the guest actually got down. >> Otherwise, if it's in mode *acpi*, then it would return immediately. >> Thus, maybe further more work need to be done in Openstack. >> >> What's your opinions, Michal and Daniel (from libvirt.org), and Chris (from openstack.org) :) >> > > > Yep, the documentation could be better in that respect. I've proposed a > patch on the libvirt upstream list: > > https://www.redhat.com/archives/libvir-list/2015-March/msg01533.html I don't think a doc patch is right. If you don't pass any flags, then it is up to the hypervisor which method it will attempt (agent or ACPI). Yes, explicitly requesting an agent as the only method to attempt might be justifiable as a reason to block, but the overall API contract is to NOT block indefinitely. I think that rather than a doc patch, we need to fix the underlying bug, and guarantee that we return after a finite time even when the agent is involved.