Testing on havana.
prep_resize() calls resource tracker's resize_claim() which creates a migration record. This record is cleared during the rt.drop_resize_claim() from confirm_resize() or revert_resize(), however if an exception is thrown before one of these is called or after, but before they clean up the migration record, then the migration record will hang around in the database indefinitely.
This results in an WARNING being logged every 60 seconds for every resize operation that ended with the instance in ERROR state as part of the update_available_resource period task, like the following:
2013-12-04 17:49:15.247 25592 WARNING nova.compute.resource_tracker [req-75e94365-1cca-4bca-92a7-19b2c62b9551 e4857f249aec4160bfa19c12eb805a96 a42cfb9766bf41869efab25703f5ce7b] [instance: 12d2551a-6403-4100-ba57-0995594c9c93] Instance not resizing, skipping migration.
This message is because the resource tracker's _update_usage_from_migrations() logs this warning if a migration record for an instance is found, but the instance's current state is not in a resize state.
These messages will be permanent in the logs even after the instance in question's state is reset, and even after a successful resize has occurred on that instance. There is no way to clean up the old migration record at this point.
It seems like there should be some handling when an exception occurs during resize, finish_resize, confirm_resize, revert_resize, etc. that will drop the resize claim, so the claim and migration record do not persist indefinitely.
There is a patch here: https:/