Public bug reported: ***This is purely based on code inspection right now.***
With a forced host live migration, we bypass the scheduler and copy the instance's resource allocations from the source node to the dest node: https://github.com/openstack/nova/blob/6be7f7248fb1c2bbb890a0a48a424e205e173c9c/nova/conductor/tasks/live_migrate.py#L109 https://github.com/openstack/nova/blob/6be7f7248fb1c2bbb890a0a48a424e205e173c9c/nova/scheduler/utils.py#L473 On successful post live migration, we remove the doubled up allocations (after logging a warning that we couldn't find allocations on the migration record): https://github.com/openstack/nova/blob/6be7f7248fb1c2bbb890a0a48a424e205e173c9c/nova/compute/manager.py#L6638L6669 However, for a failed live migration, we don't do anything like that in _rollback_live_migration. We'll call this _revert_allocation method: https://github.com/openstack/nova/blob/6be7f7248fb1c2bbb890a0a48a424e205e173c9c/nova/compute/manager.py#L6803 But it won't find allocations on the migration record and just return False: https://github.com/openstack/nova/blob/6be7f7248fb1c2bbb890a0a48a424e205e173c9c/nova/compute/manager.py#L4130 Which means the instance will have doubled up allocations on both the source and dest nodes. ** Affects: nova Importance: High Status: Triaged ** Affects: nova/queens Importance: High Status: Triaged ** Tags: live-migration placement -- 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/1784022 Title: Failed forced live migration does not rollback doubled up allocations in placement Status in OpenStack Compute (nova): Triaged Status in OpenStack Compute (nova) queens series: Triaged Bug description: ***This is purely based on code inspection right now.*** With a forced host live migration, we bypass the scheduler and copy the instance's resource allocations from the source node to the dest node: https://github.com/openstack/nova/blob/6be7f7248fb1c2bbb890a0a48a424e205e173c9c/nova/conductor/tasks/live_migrate.py#L109 https://github.com/openstack/nova/blob/6be7f7248fb1c2bbb890a0a48a424e205e173c9c/nova/scheduler/utils.py#L473 On successful post live migration, we remove the doubled up allocations (after logging a warning that we couldn't find allocations on the migration record): https://github.com/openstack/nova/blob/6be7f7248fb1c2bbb890a0a48a424e205e173c9c/nova/compute/manager.py#L6638L6669 However, for a failed live migration, we don't do anything like that in _rollback_live_migration. We'll call this _revert_allocation method: https://github.com/openstack/nova/blob/6be7f7248fb1c2bbb890a0a48a424e205e173c9c/nova/compute/manager.py#L6803 But it won't find allocations on the migration record and just return False: https://github.com/openstack/nova/blob/6be7f7248fb1c2bbb890a0a48a424e205e173c9c/nova/compute/manager.py#L4130 Which means the instance will have doubled up allocations on both the source and dest nodes. To manage notifications about this bug go to: https://bugs.launchpad.net/nova/+bug/1784022/+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
