"diagnostics" not working for libvirt driver

[Christian Berendt]

Looks like "nova diagnostics ID" is not working when using libvirt as driver (with Xen as hypervisor) on nova-compute. I received the following error.

In the code is also an hint that it's maybe not working:

---snip---
        # memoryStats might launch an exception if the method
        # is not supported by the underlying hypervisor being
        # used by libvirt
---snap---

I think there should be place some exception handling...

2012-11-08 20:21:06 AUDIT nova.compute.manager [req-57acccff-f970-47c0-9c8a-6befb4f3fc9e 5d795ef6a803425e902922bb8f817828 5536f9774f2f42f4a5d4bbc47a484ae8] [instance: f781c989-0b7e-4311-9133-7fdc933b60e5] Retrieving diagnostics
2012-11-08 20:21:06 ERROR nova.openstack.common.rpc.amqp [-] Exception during message handling
2012-11-08 20:21:06 TRACE nova.openstack.common.rpc.amqp Traceback (most recent call last):
2012-11-08 20:21:06 TRACE nova.openstack.common.rpc.amqp File "/usr/lib64/python2.6/site-packages/nova/openstack/common/rpc/amqp.py", line 275, in _process_data
2012-11-08 20:21:06 TRACE nova.openstack.common.rpc.amqp rval = self.proxy.dispatch(ctxt, version, method, **args)
2012-11-08 20:21:06 TRACE nova.openstack.common.rpc.amqp File "/usr/lib64/python2.6/site-packages/nova/openstack/common/rpc/dispatcher.py", line 145, in dispatch
2012-11-08 20:21:06 TRACE nova.openstack.common.rpc.amqp return getattr(proxyobj, method)(ctxt, **kwargs)
2012-11-08 20:21:06 TRACE nova.openstack.common.rpc.amqp File "/usr/lib64/python2.6/site-packages/nova/exception.py", line 117, in wrapped
2012-11-08 20:21:06 TRACE nova.openstack.common.rpc.amqp temp_level, payload)
2012-11-08 20:21:06 TRACE nova.openstack.common.rpc.amqp File "/usr/lib64/python2.6/contextlib.py", line 23, in __exit__
2012-11-08 20:21:06 TRACE nova.openstack.common.rpc.amqp self.gen.next()
2012-11-08 20:21:06 TRACE nova.openstack.common.rpc.amqp File "/usr/lib64/python2.6/site-packages/nova/exception.py", line 92, in wrapped
2012-11-08 20:21:06 TRACE nova.openstack.common.rpc.amqp return f(*args, **kw)
2012-11-08 20:21:06 TRACE nova.openstack.common.rpc.amqp File "/usr/lib64/python2.6/site-packages/nova/compute/manager.py", line 202, in decorated_function
2012-11-08 20:21:06 TRACE nova.openstack.common.rpc.amqp kwargs['instance']['uuid'], e, sys.exc_info())
2012-11-08 20:21:06 TRACE nova.openstack.common.rpc.amqp File "/usr/lib64/python2.6/contextlib.py", line 23, in __exit__
2012-11-08 20:21:06 TRACE nova.openstack.common.rpc.amqp self.gen.next()
2012-11-08 20:21:06 TRACE nova.openstack.common.rpc.amqp File "/usr/lib64/python2.6/site-packages/nova/compute/manager.py", line 196, in decorated_function
2012-11-08 20:21:06 TRACE nova.openstack.common.rpc.amqp return function(self, context, *args, **kwargs)
2012-11-08 20:21:06 TRACE nova.openstack.common.rpc.amqp File "/usr/lib64/python2.6/site-packages/nova/compute/manager.py", line 1786, in get_diagnostics
2012-11-08 20:21:06 TRACE nova.openstack.common.rpc.amqp return self.driver.get_diagnostics(instance)
2012-11-08 20:21:06 TRACE nova.openstack.common.rpc.amqp File "/usr/lib64/python2.6/site-packages/nova/virt/libvirt/driver.py", line 2985, in get_diagnostics
2012-11-08 20:21:06 TRACE nova.openstack.common.rpc.amqp for key in mem.keys():
2012-11-08 20:21:06 TRACE nova.openstack.common.rpc.amqp AttributeError: 'NoneType' object has no attribute 'keys'
2012-11-08 20:21:06 TRACE nova.openstack.common.rpc.amqp
2012-11-08 20:21:06 ERROR nova.openstack.common.rpc.common [-] Returning exception 'NoneType' object has no attribute 'keys' to caller

[Christian Berendt (berendt)]

exception handling has to be more generic to also fetch the AttributeError. I'll commit a bugfix.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/15662

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/15662
Committed: http://github.com/openstack/nova/commit/0406d1f85fa93db4e4d5ab8b37d298951d4c4193
Submitter: Jenkins
Branch: master

commit 0406d1f85fa93db4e4d5ab8b37d298951d4c4193
Author: Christian Berendt <email address hidden>
Date: Thu Nov 8 20:41:07 2012 +0100

    make diagnostics workable for libvirt with Xen

    When using "diagnostics" with libvirt as driver on nova-compute
    and Xen as hypervisor the call to domain.memoryStats() in
    get_diagnostics() doesn't fail with a libvirt.libvirtError,
    but with an AttributeError. This exception should be catched, too.

    The method virDomainMemoryStats is not implemented in libvirt
    for Xen.

    fixes bug 1076527

    Change-Id: I16645654b346e3c40ff3dd63f20600c802cbeb3f