BSN: Set inconsistency record on delete failure

Set a bad value in the consistency DB on a delete
failure so a sync is triggered the next time the backend
servers become available.

This fixes the issue where the backend servers are unavailable
when an object is deleted from ML2 but not deleted from the
backend.

Conflicts:
	neutron/tests/unit/bigswitch/test_servermanager.py

Closes-Bug: #1377350
Change-Id: I24713a03af4d3499645241f900de1f572689c235
(cherry picked from commit e9f001a63a555f067c4567a88613d14853442524)

2 files changed, 20 insertions, 0 deletions

diff --git a/neutron/plugins/bigswitch/servermanager.py b/neutron/plugins/bigswitch/servermanager.py
index c10ce72bb5..7b43ccfbcd 100644
--- a/neutron/plugins/bigswitch/servermanager.py
+++ b/neutron/plugins/bigswitch/servermanager.py
@@ -473,6 +473,13 @@ class ServerPool(object):
                            'data': ret[3]})
                 active_server.failed = True
 
+        # A failure on a delete means the object is gone from Neutron but not
+        # from the controller. Set the consistency hash to a bad value to
+        # trigger a sync on the next check.
+        # NOTE: The hash must have a comma in it otherwise it will be ignored
+        # by the backend.
+        if action == 'DELETE':
+            hash_handler.put_hash('INCONSISTENT,INCONSISTENT')
         # All servers failed, reset server list and try again next time
         LOG.error(_('ServerProxy: %(action)s failure for all servers: '
                     '%(server)r'),
diff --git a/neutron/tests/unit/bigswitch/test_servermanager.py b/neutron/tests/unit/bigswitch/test_servermanager.py
index e8d15efa3b..c3ea3b887a 100644
--- a/neutron/tests/unit/bigswitch/test_servermanager.py
+++ b/neutron/tests/unit/bigswitch/test_servermanager.py
@@ -23,6 +23,7 @@ from neutron import context
 from neutron import manager
 from neutron.openstack.common import importutils
 from neutron.openstack.common import jsonutils
+from neutron.plugins.bigswitch.db import consistency_db as cdb
 from neutron.plugins.bigswitch import servermanager
 from neutron.tests.unit.bigswitch import test_restproxy_plugin as test_rp
 
@@ -411,6 +412,18 @@ class ServerManagerTests(test_rp.BigSwitchProxyPluginV2TestCase):
             sleep_call_count = rest_call_count - 1
             tmock.assert_has_calls(sleep_call * sleep_call_count)
 
+    def test_delete_failure_sets_bad_hash(self):
+        pl = manager.NeutronManager.get_plugin()
+        hash_handler = cdb.HashHandler()
+        with mock.patch(
+            SERVERMANAGER + '.ServerProxy.rest_call',
+            return_value=(httplib.INTERNAL_SERVER_ERROR, 0, 0, 0)
+        ):
+            # a failed delete call should put a bad hash in the DB
+            pl.servers.rest_call('DELETE', '/', '', None, [])
+            self.assertEqual('INCONSISTENT,INCONSISTENT',
+                             hash_handler.read_for_update())
+
     def test_conflict_triggers_sync(self):
         pl = manager.NeutronManager.get_plugin()
         with mock.patch(