Comment 4 for bug 1764269

Another situation where the "generated object list" returns empty is when a large number of volume backup deletes are performed. For example (this is an extreme, but possible, example that I tested), when 1,000 commands such as:

openstack volume backup delete <uuid> &

are run in a bash shell, with valid UUIDs of non-deleted backups (those that have objects reported by Swift), many of the backups are marked as deleted in the Cinder database, but the objects are orphaned on the object storage.

One of the volume backups that was deleted and has orphaned objects produced these two cinder-backup.log entries:

/var/lib/docker/volumes/kolla_logs/_data/cinder/cinder-backup.log:2019-09-30 16:20:33.367 6 DEBUG cinder.backup.chunkeddriver [req-9434f1e1-c382-4d86-8f81-55602dc28185 720763d70a094bf3b11ebabd31eee896 8acb2072057b45ab9da245880af92c93 - default default] delete started, backup: 6efd5baf-4914-411c-bc20-d9fb53504c6d, container: volumebackups, prefix: volume_77bd1522-68d6-43d3-8178-04a096c6db95/20190529071528/az_us-central-1a_backup_6efd5baf-4914-411c-bc20-d9fb53504c6d. delete_backup /var/lib/kolla/venv/lib/python2.7/site-packages/cinder/backup/chunkeddriver.py:807

/var/lib/docker/volumes/kolla_logs/_data/cinder/cinder-backup.log:2019-09-30 16:20:33.418 6 DEBUG cinder.backup.chunkeddriver [req-9434f1e1-c382-4d86-8f81-55602dc28185 720763d70a094bf3b11ebabd31eee896 8acb2072057b45ab9da245880af92c93 - default default] generated object list: []. _generate_object_names /var/lib/kolla/venv/lib/python2.7/site-packages/cinder/backup/chunkeddriver.py:232

showing that it wasn't able to retrieve the object list (but did not error in any way) - even though I can list the objects successfully from this user's account using:

swift list volumebackups -p volume_77bd1522-68d6-43d3-8178-04a096c6db95/20190529071528/az_us-central-1a_backup_6efd5baf-4914-411c-bc20-d9fb53504c6d

Eric