Fix live-migration in multi_host network

 * call teardown after live migration
 * call update a second time after migration for dhcp
 * moves the instance state update into post_live_migrate
 * completes the fix for bug 939060
 * fixes bug 947326

Change-Id: I042567573b9bb46381c5447aa08e83cd1916b225

2 files changed, 24 insertions, 22 deletions

diff --git a/nova/compute/manager.py b/nova/compute/manager.py
index 6572c5a3a..889e9e5f0 100644
--- a/nova/compute/manager.py
+++ b/nova/compute/manager.py
@@ -2000,10 +2000,6 @@ class ComputeManager(manager.SchedulerDependentManager):
         # Releasing vlan.
         # (not necessary in current implementation?)
 
-        # NOTE(tr3buchet): tear down networks on source host
-        self.network_api.setup_networks_on_host(ctxt, instance_ref,
-                                                self.host, teardown=True)
-
         network_info = self._get_instance_nw_info(ctxt, instance_ref)
         # Releasing security group ingress rule.
         self.driver.unfilter_instance(instance_ref,
@@ -2041,15 +2037,6 @@ class ComputeManager(manager.SchedulerDependentManager):
                       "args": {'instance_id': instance_ref['id'],
                                'block_migration': block_migration}})
 
-        # Restore instance state
-        current_power_state = self._get_power_state(ctxt, instance_ref)
-        self._instance_update(ctxt,
-                              instance_ref["id"],
-                              host=dest,
-                              power_state=current_power_state,
-                              vm_state=vm_states.ACTIVE,
-                              task_state=None)
-
         # Restore volume state
         for volume_ref in instance_ref['volumes']:
             self.volume_api.update(ctxt, volume_ref, {'status': 'in-use'})
@@ -2067,6 +2054,10 @@ class ComputeManager(manager.SchedulerDependentManager):
             self.driver.unplug_vifs(instance_ref,
                                     self._legacy_nw_info(network_info))
 
+        # NOTE(tr3buchet): tear down networks on source host
+        self.network_api.setup_networks_on_host(ctxt, instance_ref,
+                                                self.host, teardown=True)
+
         LOG.info(_('Migrating instance to %(dest)s finished successfully.'),
                  locals(), instance=instance_ref)
         LOG.info(_("You may see the error \"libvirt: QEMU error: "
@@ -2098,6 +2089,19 @@ class ComputeManager(manager.SchedulerDependentManager):
         self.driver.post_live_migration_at_destination(context, instance_ref,
                                             self._legacy_nw_info(network_info),
                                             block_migration)
+        # Restore instance state
+        current_power_state = self._get_power_state(context, instance_ref)
+        self._instance_update(context,
+                              instance_ref['id'],
+                              host=self.host,
+                              power_state=current_power_state,
+                              vm_state=vm_states.ACTIVE,
+                              task_state=None)
+
+        # NOTE(vish): this is necessary to update dhcp
+        self.network_api.setup_networks_on_host(context,
+                                                instance_ref,
+                                                self.host)
 
     def rollback_live_migration(self, context, instance_ref,
                                 dest, block_migration):
diff --git a/nova/tests/test_compute.py b/nova/tests/test_compute.py
index bcfe90e0e..f30fefeba 100644
--- a/nova/tests/test_compute.py
+++ b/nova/tests/test_compute.py
@@ -1387,26 +1387,24 @@ class ComputeTestCase(BaseTestCase):
         self.mox.StubOutWithMock(self.compute.driver, 'unfilter_instance')
         self.compute.driver.unfilter_instance(i_ref, [])
         self.mox.StubOutWithMock(rpc, 'call')
-        rpc.call(c, 'network', {'method': 'setup_networks_on_host',
-                                'args': {'instance_id': instance_id,
-                                         'host': self.compute.host,
-                                         'teardown': True}})
         rpc.call(c, db.queue_get_for(c, FLAGS.compute_topic, dest),
             {"method": "post_live_migration_at_destination",
              "args": {'instance_id': i_ref['id'], 'block_migration': False}})
         self.mox.StubOutWithMock(self.compute.driver, 'unplug_vifs')
         self.compute.driver.unplug_vifs(i_ref, [])
+        rpc.call(c, 'network', {'method': 'setup_networks_on_host',
+                                'args': {'instance_id': instance_id,
+                                         'host': self.compute.host,
+                                         'teardown': True}})
 
         # start test
         self.mox.ReplayAll()
         self.compute.post_live_migration(c, i_ref, dest)
 
-        # make sure every data is rewritten to destinatioin hostname.
-        i_ref = db.instance_get(c, i_ref['id'])
-        c1 = (i_ref['host'] == dest)
+        # make sure floating ips are rewritten to destinatioin hostname.
         flo_refs = db.floating_ip_get_all_by_host(c, dest)
-        c2 = (len(flo_refs) != 0 and flo_refs[0]['address'] == flo_addr)
-        self.assertTrue(c1 and c2)
+        self.assertTrue(flo_refs)
+        self.assertEqual(flo_refs[0]['address'], flo_addr)
 
         # cleanup
         db.instance_destroy(c, instance_id)