Public bug reported: Hi all. It appears that there is no way, on newer API versions, of "forcing" a destination host while performing a live migration.
We have seen this yesterday while trying to migrate some instances with a scheduler hint for the JsonFilter. The hint was something like "hypervisor_hostname in list of hosts". Obviously, we had some problems with our hosts and needed to evacuate them, but the scheduler hint prevented us from migrating the instances. We had to disable the JsonFilter, perform the migration, and enable the filter again. Checking at the docs for the API (https://docs.openstack.org/api- ref/compute/#live-migrate-server-os-migratelive-action), it appears that specifying a destination host for a migration does not bypass the scheduler, for API microversion >= 2.30. Also, it seems that the force option is available only until API microversion 2.67. So, is there no way of overriding, removing or ignoring scheduler hints during a migration? I understand completely bypassing scheduler filters may be dangerous (specially when things like NUMA topology have to be considered), but I also think it should be a supported use case to "change our minds" about a hint, specially while migrating. ** Affects: nova Importance: Undecided Status: New -- 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/2078932 Title: No way of removing scheduler hints while migrating on newer APIs? Status in OpenStack Compute (nova): New Bug description: Hi all. It appears that there is no way, on newer API versions, of "forcing" a destination host while performing a live migration. We have seen this yesterday while trying to migrate some instances with a scheduler hint for the JsonFilter. The hint was something like "hypervisor_hostname in list of hosts". Obviously, we had some problems with our hosts and needed to evacuate them, but the scheduler hint prevented us from migrating the instances. We had to disable the JsonFilter, perform the migration, and enable the filter again. Checking at the docs for the API (https://docs.openstack.org/api- ref/compute/#live-migrate-server-os-migratelive-action), it appears that specifying a destination host for a migration does not bypass the scheduler, for API microversion >= 2.30. Also, it seems that the force option is available only until API microversion 2.67. So, is there no way of overriding, removing or ignoring scheduler hints during a migration? I understand completely bypassing scheduler filters may be dangerous (specially when things like NUMA topology have to be considered), but I also think it should be a supported use case to "change our minds" about a hint, specially while migrating. To manage notifications about this bug go to: https://bugs.launchpad.net/nova/+bug/2078932/+subscriptions -- Mailing list: https://launchpad.net/~yahoo-eng-team Post to : yahoo-eng-team@lists.launchpad.net Unsubscribe : https://launchpad.net/~yahoo-eng-team More help : https://help.launchpad.net/ListHelp
