init_host offload to default to true

The backup_service_inithost_offload (introduced in
If9d9e454cdd48669db6e4b8d96f340bbb6f99fad) configuration option
is false by default. Lots of deleting backups will block the
startup of the service for longer than acceptable. We should
also default this option to True to avoid delaying startup.

UpgradeImpact

Change-Id: Ia280dba770f4509cdf80563a89738cdc058015ee

cinder/backup/manager.py

@@ -61,9 +61,11 @@ backup_manager_opts = [
                default='cinder.backup.drivers.swift',
                help='Driver to use for backups.',),
     cfg.BoolOpt('backup_service_inithost_offload',
-                default=False,
+                default=True,
                 help='Offload pending backup delete during '
-                     'backup service startup.',),
+                     'backup service startup. If false, the backup service '
+                     'will remain down until all pending backups are '
+                     'deleted.',),
 ]
 
 # This map doesn't need to be extended in the future since it's only
@@ -192,7 +194,7 @@ class BackupManager(manager.SchedulerDependentManager):
                 # from being blocked.
                 self._add_to_threadpool(self.delete_backup, ctxt, backup)
             else:
-                # By default, delete backups sequentially
+                # Delete backups sequentially
                 self.delete_backup(ctxt, backup)
 
     def _detach_all_attachments(self, ctxt, volume):

cinder/tests/unit/test_backup.py

@@ -211,6 +211,8 @@ class BackupTestCase(BaseBackupTest):
         def get_admin_context():
             return self.ctxt
 
+        self.override_config('backup_service_inithost_offload', False)
+
         vol1_id = self._create_volume_db_entry()
         self._create_volume_attach(vol1_id)
         db.volume_update(self.ctxt, vol1_id, {'status': 'backing-up'})
@@ -276,7 +278,6 @@ class BackupTestCase(BaseBackupTest):
     def test_init_host_with_service_inithost_offload(self,
                                                      mock_add_threadpool,
                                                      mock_get_all_by_host):
-        self.override_config('backup_service_inithost_offload', True)
         vol1_id = self._create_volume_db_entry()
         db.volume_update(self.ctxt, vol1_id, {'status': 'available'})
         backup1 = self._create_backup_db_entry(
@@ -410,6 +411,8 @@ class BackupTestCase(BaseBackupTest):
     def test_cleanup_one_deleting_backup(self):
         """Test cleanup_one_backup for volume status 'deleting'."""
 
+        self.override_config('backup_service_inithost_offload', False)
+
         backup = self._create_backup_db_entry(
             status=fields.BackupStatus.DELETING)
 

releasenotes/notes/bug-1570845-efdb0206718f4ca4.yaml

@@ -0,0 +1,4 @@
+---
+upgrade:
+  - The 'backup_service_inithost_offload' configuration
+    option now defaults to 'True' instead of 'False'.