xenapi sync_power_states peridodic task can traceback when instance not found

[Andrew Laski]

When an instance is not found on the hypervisor during the sync_power_states periodic task, possibly because it's being resized/migrated, there's a traceback in the compute logs.

2013-09-10 17:46:27.736 32525 ERROR nova.openstack.common.periodic_task [-] Error during ComputeManager._sync_power_states: Could not find VM with name instance-00ab07fd-b5b0-44cb-8b62-9df838c7f468
2013-09-10 17:46:27.736 32525 TRACE nova.openstack.common.periodic_task Traceback (most recent call last):
2013-09-10 17:46:27.736 32525 TRACE nova.openstack.common.periodic_task File "/opt/rackstack/410.23/nova/lib/python2.6/site-packages/nova/openstack/common/periodic_task.py", line 180, in run_periodic_tasks
2013-09-10 17:46:27.736 32525 TRACE nova.openstack.common.periodic_task task(self, context)
2013-09-10 17:46:27.736 32525 TRACE nova.openstack.common.periodic_task File "/opt/rackstack/410.23/nova/lib/python2.6/site-packages/nova/compute/manager.py", line 4623, in _sync_power_states
2013-09-10 17:46:27.736 32525 TRACE nova.openstack.common.periodic_task vm_instance = self.driver.get_info(db_instance)
2013-09-10 17:46:27.736 32525 TRACE nova.openstack.common.periodic_task File "/opt/rackstack/410.23/nova/lib/python2.6/site-packages/nova/virt/xenapi/driver.py", line 318, in get_info
2013-09-10 17:46:27.736 32525 TRACE nova.openstack.common.periodic_task return self._vmops.get_info(instance)
2013-09-10 17:46:27.736 32525 TRACE nova.openstack.common.periodic_task File "/opt/rackstack/410.23/nova/lib/python2.6/site-packages/nova/virt/xenapi/vmops.py", line 1488, in get_info
2013-09-10 17:46:27.736 32525 TRACE nova.openstack.common.periodic_task vm_ref = vm_ref or self._get_vm_opaque_ref(instance)
2013-09-10 17:46:27.736 32525 TRACE nova.openstack.common.periodic_task File "/opt/rackstack/410.23/nova/lib/python2.6/site-packages/nova/virt/xenapi/vmops.py", line 800, in _get_vm_opaque_ref
2013-09-10 17:46:27.736 32525 TRACE nova.openstack.common.periodic_task instance['name'])
2013-09-10 17:46:27.736 32525 TRACE nova.openstack.common.periodic_task NotFound: Could not find VM with name instance-00ab07fd-b5b0-44cb-8b62-9df838c7f468
2013-09-10 17:46:27.736 32525 TRACE nova.openstack.common.periodic_task

This is happening because the xenapi raises a NotFound exception but the sync_power_states task is expecting an InstanceNotFound exception. NotFound is a general exception and InstanceNotFound is a more specific one so it would be better to raise InstanceNotFound and catch NotFound. But for this case it should be ok to just raise InstanceNotFound.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/47012

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/47012
Committed: http://github.com/openstack/nova/commit/983d815a80039d1f4e0d735c3041882833ecc488
Submitter: Jenkins
Branch: master

commit 983d815a80039d1f4e0d735c3041882833ecc488
Author: Andrew Laski <email address hidden>
Date: Tue Sep 17 15:14:56 2013 -0400

    XenAPI raise InstanceNotFound in _get_vm_opaque_ref

    If _get_vm_opaque_ref doesn't find an instance it should raise a
    specific InstanceNotFound exception rather than the general NotFound
    exception. Callers of this method may try to catch InstanceNotFound or
    NotFound and now both will work.

    This fix will prevent a traceback during the _sync_power_states periodic
    task which is expecting an InstanceNotFound exception.

    Change-Id: Ia28fe33d69520806dab878c843fe435e018a20de
    Closes-Bug: 1226756