Comment 13 for bug 1889765

>Ubuntu SRU information<

[Impact]
During a server hard failure (power off) Masakari will fail to complete recovery of impacted instances if the server comes back up before Masakari has completed recovery of all instances.

[Test Case]
Deploy OpenStack with Masakari configuration (using the OpenStack Charms)
1) Create a segment and add the node
2) Create enough VMs so Masakari will take some time on the evacuation (e.g. 30 VMs)
3) Reboot the node
4) Masakari starts the migration of the VMs
5) Node eventually comes back and nova-compute is up & running while Masakari is still evacuating VMs

[Regression Potential]
The proposed cherry pick resolves some incorrect assumptions in the exception processing within Masakari which resolves this issue; behaviour is not changed and the fix has been upstream in Masakari for some time.