Restart of nova-compute service fails

[Marian Horban]

After sending HUP signal to nova-compute process we can observe trace in logs:

2015-11-30 10:35:26.509 INFO oslo_service.service [req-ecb7f866-b041-4abb-9037-164443b8387f None None] Caught SIGHUP, exiting
2015-11-30 10:35:31.894 DEBUG oslo_concurrency.lockutils [req-ecb7f866-b041-4abb-9037-164443b8387f None None] Acquired semaphore "singleton_lock" from (pid=24742) lock /usr/local/lib/python2.7/dist-packages/oslo_concurrency/lockutils.py:212
2015-11-30 10:35:31.900 DEBUG oslo_concurrency.lockutils [req-ecb7f866-b041-4abb-9037-164443b8387f None None] Releasing semaphore "singleton_lock" from (pid=24742) lock /usr/local/lib/python2.7/dist-packages/oslo_concurrency/lockutils.py:225
2015-11-30 10:35:31.903 ERROR nova.service [req-ecb7f866-b041-4abb-9037-164443b8387f None None] Service error occurred during cleanup_host
2015-11-30 10:35:31.903 TRACE nova.service Traceback (most recent call last):
2015-11-30 10:35:31.903 TRACE nova.service File "/opt/stack/nova/nova/service.py", line 312, in stop
2015-11-30 10:35:31.903 TRACE nova.service self.manager.cleanup_host()
2015-11-30 10:35:31.903 TRACE nova.service File "/opt/stack/nova/nova/compute/manager.py", line 1323, in cleanup_host
2015-11-30 10:35:31.903 TRACE nova.service self.instance_events.cancel_all_events()
2015-11-30 10:35:31.903 TRACE nova.service File "/opt/stack/nova/nova/compute/manager.py", line 578, in cancel_all_events
2015-11-30 10:35:31.903 TRACE nova.service for instance_uuid, events in our_events.items():
2015-11-30 10:35:31.903 TRACE nova.service AttributeError: 'NoneType' object has no attribute 'items'
2015-11-30 10:35:31.903 TRACE nova.service

[Marian Horban (mhorban)]

Method service.stop() is called twice during restart of service started with ServiceLauncher.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/258441

[stgleb (gstepanov)]

I've found that nova compute handles SIGHUP properly, but if you send one more - it stops compute service.

[Davanum Srinivas (DIMS) (dims-v)]

So there's nothing more to do. right? :)

[Sean Dague (sdague)]

https://review.openstack.org/#/c/258441/4 is stalled on merge conflict and not having any tests. That's needed for this to be completed.

[OpenStack Infra (hudson-openstack)]

Change abandoned by Michael Still (<email address hidden>) on branch: master
Review: https://review.openstack.org/258441
Reason: This patch is very stale. I am abandoning it to keep the review queue sane.

[Xuanzhou Perry Dong (oss-xzdong)]

Already fixed by: https://review.openstack.org/284287