Nova might spawn without waiting for network-vif-plugged event

[Salvatore Orlando]

This applies only when the nova/neutron event reporting mechanism is enabled.

It has been observed that in some cases Nova spawns an instance without waiting for network-vif-plugged event, even if the vif was unplugged and then plugged again.

This happens because the status of the VIF in the network info cache is not updated when such events are received.
Therefore the cache contains an out-of-date value and the VIF might already be in status ACTIVE when the instance is being spawned. However there is no guarantee that this would be the actual status of the VIF.

For instance in this case there are only two instances in which nova starts waiting for 'network-vif-plugged' on f800d4a8-0a01-475f-bd34-8d975ce6f1ab. However this instance is used in tempest.api.compute.servers.test_server_actions, and the tests in this suite should trigger more than 2 events requiring a respawn of an instance after unplugging vifs.

From what can be gathered by logs, this issue, if confirmed, should occur only when actions such as stop, resize, reboot_hard are executed on a instance.

[Tracy Jones (tjones-i)]

Sounds like this is related to https://bugs.launchpad.net/nova/+bug/1338679

[Lee (leethomas944)]

Hi, I'd like to try my hand at this bug. I've checked out:

/nova/compute/manager.py
/nova/network/model.py
/nova/objects/external_event.py

and I'm not seeing where it all ties together. At what point should the "network_info" cache be updated? Can someone point me in the right direction, please? Thank you.

[Markus Zoeller (markus_z) (mzoeller)]

This is an automated cleanup. This bug report has been closed because it
is older than 18 months and there is no open code change to fix this.
After this time it is unlikely that the circumstances which lead to
the observed issue can be reproduced.

If you can reproduce the bug, please:
* reopen the bug report (set to status "New")
* AND add the detailed steps to reproduce the issue (if applicable)
* AND leave a comment "CONFIRMED FOR: <RELEASE_NAME>"
  Only still supported release names are valid (LIBERTY, MITAKA, OCATA, NEWTON).
  Valid example: CONFIRMED FOR: LIBERTY