Failed to update object doesn't have attribute

[Hiroyuki Eguchi]

I'm evaluating a rolling upgrade of nova from liberty to mitaka in sr-iov environment.

The following error occurred in resource_tracker in case controller node is mitaka and compute node is liberty.

Error updating resources for node compute0: Cannot load 'parent_addr' in the base classTraceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/nova/conductor/manager.py", line 85, in _object_dispatch
    return getattr(target, method)(*args, **kwargs)
  File "/usr/lib/python2.7/site-packages/oslo_versionedobjects/base.py", line 223, in wrapper
    return fn(self, *args, **kwargs)
  File "/usr/lib/python2.7/site-packages/nova/objects/pci_device.py", line 251, in save
    updates = self.obj_get_changes()
  File "/usr/lib/python2.7/site-packages/oslo_versionedobjects/base.py", line 604, in obj_get_changes
    changes[key] = getattr(self, key)
  File "/usr/lib/python2.7/site-packages/oslo_versionedobjects/base.py", line 67, in getter
    self.obj_load_attr(name)
  File "/usr/lib/python2.7/site-packages/oslo_versionedobjects/base.py", line 580, in obj_load_attr
    _("Cannot load '%s' in the base class") % attrname)
NotImplementedError: Cannot load 'parent_addr' in the base class

The cause of error is that a parent_addr parameter which has been added newly since mitaka is not set correctly.

We should consider a old version object doesn't have a new attribute when updating.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/358964

[Hiroyuki Eguchi (h-eguchi)]

Fix proposed to branch: master
Review: https://review.openstack.org/359601

[Hiroyuki Eguchi (h-eguchi)]

Could anyone review this?

[Swe W Aung (sirswa)]

Is there any update? We are hitting this issue now.
controller running mitaka and compute nodes in liberty.

[OpenStack Infra (hudson-openstack)]

Change abandoned by Stephen Finucane (<email address hidden>) on branch: master
Review: https://review.opendev.org/359601
Reason: Fair to say this is dead in the water now