Reviewed: https://review.opendev.org/698037 Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=e6f742544432d6066f1fba4666580919eb7859bd Submitter: Zuul Branch: master
commit e6f742544432d6066f1fba4666580919eb7859bd Author: Eric Fried <[email protected]> Date: Mon Dec 9 09:58:53 2019 -0600 Nix os-server-external-events 404 condition The POST /os-server-external-events API had the following confusing behavior: With multiple events in the payload, if *some* (but not all) were dropped, the HTTP response was 207, with per-event 4xx error codes in the payload. But if *all* of the events were dropped, the overall HTTP response was 404 with no payload. Thus, especially for consumers sending only one event at a time, it was impossible to distinguish e.g. "you tried to send an event for a nonexistent instance" from "the instance you specified hasn't landed on a host yet". This fix gets rid of that sweeping 404 condition, so if *any* subset of the events are dropped (including *all* of them), the HTTP response will always be 207, and the payload will always contain granular per-event error codes. This effectively means the API can no longer return 404, ever. Closes-Bug: #1855752 Change-Id: Ibad1b51e2cf50d00102295039b6e82bc00bec058 ** Changed in: nova Status: In Progress => Fix Released -- You received this bug notification because you are a member of Yahoo! Engineering Team, which is subscribed to OpenStack Compute (nova). https://bugs.launchpad.net/bugs/1855752 Title: Inappropriate HTTP error status from os-server-external-events Status in OpenStack Compute (nova): Fix Released Bug description: The handling of os-server-external-events API [1] has a bug. It is designed to handle multiple events, with the following expected behavior: * If all events are successfully handled, it should return HTTP 200. * If no event is successfully handled, it should return HTTP 404. * If some are handled successfully but not all, it should return HTTP 207, with per-event status codes. However, when Cyborg sends a single event for a single instance, and that instance is not yet associated with a host [*], the 'else' clause in Line 137 [1] will set HTTP 207 as return code; but, since accepted_events is [] in Line 146, that will throw an exception and return 404. IOW, the expected return is 207 but the actual return is 404. This has been discussed in IRC [2]. A patch has been proposed [3] to address this. [*] This happens because Nova calls into Cyborg from the conductor to initiate binding of accelerator requests (ARQs), lets it proceed asynchronously, and waits for the binding notification event in the compute manager. The notification event could come before the compute manager has called self._rt.instance_claim(), which would associate the instance with a host and a node. That race condition triggers the behavior above. [1] https://github.com/openstack/nova/blob/62f6a0a1bc6c4b24621e1c2e927177f99501bef3/nova/api/openstack/compute/server_external_events.py [2] http://eavesdrop.openstack.org/irclogs/%23openstack-nova /%23openstack-nova.2019-12-09.log.html#t2019-12-09T15:45:18 [3] https://review.opendev.org/#/c/698037/ To manage notifications about this bug go to: https://bugs.launchpad.net/nova/+bug/1855752/+subscriptions -- Mailing list: https://launchpad.net/~yahoo-eng-team Post to : [email protected] Unsubscribe : https://launchpad.net/~yahoo-eng-team More help : https://help.launchpad.net/ListHelp
