Public bug reported: We have a performance regression since Stein [1] when listing servers with details concerning the host_status field. The code used to rely on this method [2] to cache the host status information per host when iterating over a list of instances but now it fetches it per host per instance in the view builder [3]. Granted by default policy this would only affect performance for an admin, but if I'm an admin listing 1000 servers across all tenants using "nova list --all-tenants" (which is going to use a microversion high enough to hit this) it could be a noticeable slow down compared to before Stein.
[1] https://review.opendev.org/#/c/584590/ [2] https://github.com/openstack/nova/blob/c7e9e667426a6d88d396a59cb40d30763a3265f9/nova/compute/api.py#L4926 [3] https://github.com/openstack/nova/blob/c7e9e667426a6d88d396a59cb40d30763a3265f9/nova/api/openstack/compute/views/servers.py#L325 ** Affects: nova Importance: Medium Status: Triaged ** Affects: nova/stein Importance: Medium Status: Triaged ** Tags: performance ** Changed in: nova Status: New => Triaged ** Also affects: nova/stein Importance: Undecided Status: New ** Changed in: nova/stein Status: New => Triaged ** Changed in: nova/stein Importance: Undecided => High ** Summary changed: - Inefficient host_status lookup when listing servers with details + Inefficient host_status lookup when listing servers with details (regression) ** Changed in: nova/stein Importance: High => Medium -- 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/1830260 Title: Inefficient host_status lookup when listing servers with details (regression) Status in OpenStack Compute (nova): Triaged Status in OpenStack Compute (nova) stein series: Triaged Bug description: We have a performance regression since Stein [1] when listing servers with details concerning the host_status field. The code used to rely on this method [2] to cache the host status information per host when iterating over a list of instances but now it fetches it per host per instance in the view builder [3]. Granted by default policy this would only affect performance for an admin, but if I'm an admin listing 1000 servers across all tenants using "nova list --all-tenants" (which is going to use a microversion high enough to hit this) it could be a noticeable slow down compared to before Stein. [1] https://review.opendev.org/#/c/584590/ [2] https://github.com/openstack/nova/blob/c7e9e667426a6d88d396a59cb40d30763a3265f9/nova/compute/api.py#L4926 [3] https://github.com/openstack/nova/blob/c7e9e667426a6d88d396a59cb40d30763a3265f9/nova/api/openstack/compute/views/servers.py#L325 To manage notifications about this bug go to: https://bugs.launchpad.net/nova/+bug/1830260/+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
