Send full instance to compute live_migration.

Remove the instance_id parameter and send a full instance to
live_migration in the compute manager.  This cuts down on database
access required by the compute manager.

Part of blueprint no-db-messaging.

Change-Id: Ic21f061702704ddeaa6925aac4ecad69b0e8de18

6 files changed, 42 insertions, 29 deletions

diff --git a/nova/compute/manager.py b/nova/compute/manager.py
index e57881e88..0da0e7319 100644
--- a/nova/compute/manager.py
+++ b/nova/compute/manager.py
@@ -273,7 +273,7 @@ def _get_image_meta(context, image_ref):
 class ComputeManager(manager.SchedulerDependentManager):
     """Manages the running instances from creation to destruction."""
 
-    RPC_API_VERSION = '1.39'
+    RPC_API_VERSION = '1.40'
 
     def __init__(self, compute_driver=None, *args, **kwargs):
         """Load configuration options and connect to the hypervisor."""
@@ -2201,48 +2201,50 @@ class ComputeManager(manager.SchedulerDependentManager):
         if block_migration:
             self.driver.pre_block_migration(context, instance, disk)
 
-    def live_migration(self, context, instance_id,
-                       dest, block_migration=False):
+    def live_migration(self, context, dest, block_migration=False,
+                       instance=None, instance_id=None):
         """Executing live migration.
 
         :param context: security context
-        :param instance_id: nova.db.sqlalchemy.models.Instance.Id
+        :param instance_id: (deprecated) nova.db.sqlalchemy.models.Instance.Id
+        :param instance: instance dict
         :param dest: destination host
         :param block_migration: if true, prepare for block migration
 
         """
         # Get instance for error handling.
-        instance_ref = self.db.instance_get(context, instance_id)
+        if not instance:
+            instance = self.db.instance_get(context, instance_id)
 
         try:
             # Checking volume node is working correctly when any volumes
             # are attached to instances.
-            if self._get_instance_volume_bdms(context, instance_ref['uuid']):
+            if self._get_instance_volume_bdms(context, instance['uuid']):
                 rpc.call(context,
                           FLAGS.volume_topic,
                           {'method': 'check_for_export',
-                           'args': {'instance_id': instance_id}})
+                           'args': {'instance_id': instance['id']}})
 
             if block_migration:
-                disk = self.driver.get_instance_disk_info(instance_ref.name)
+                disk = self.driver.get_instance_disk_info(instance['name'])
             else:
                 disk = None
 
-            self.compute_rpcapi.pre_live_migration(context, instance_ref,
+            self.compute_rpcapi.pre_live_migration(context, instance,
                     block_migration, disk, dest)
 
         except Exception:
             with excutils.save_and_reraise_exception():
-                instance_uuid = instance_ref['uuid']
+                instance_uuid = instance['uuid']
                 LOG.exception(_('Pre live migration failed at  %(dest)s'),
-                              locals(), instance=instance_ref)
-                self.rollback_live_migration(context, instance_ref, dest,
+                              locals(), instance=instance)
+                self.rollback_live_migration(context, instance, dest,
                                              block_migration)
 
         # Executing live migration
         # live_migration might raises exceptions, but
         # nothing must be recovered in this version.
-        self.driver.live_migration(context, instance_ref, dest,
+        self.driver.live_migration(context, instance, dest,
                                    self._post_live_migration,
                                    self.rollback_live_migration,
                                    block_migration)
diff --git a/nova/compute/rpcapi.py b/nova/compute/rpcapi.py
index 72babd380..9b98f2ef5 100644
--- a/nova/compute/rpcapi.py
+++ b/nova/compute/rpcapi.py
@@ -118,6 +118,7 @@ class ComputeAPI(nova.openstack.common.rpc.proxy.RpcProxy):
                 - remove instance_type_id, add instance_type
                 - remove topic, it was unused
         1.39 - Remove instance_uuid, add instance argument to run_instance()
+        1.40 - Remove instance_id, add instance argument to live_migration()
     '''
 
     BASE_RPC_API_VERSION = '1.0'
@@ -275,6 +276,13 @@ class ComputeAPI(nova.openstack.common.rpc.proxy.RpcProxy):
                 topic=_compute_topic(self.topic, ctxt, None, instance),
                 version='1.19')
 
+    def live_migration(self, ctxt, instance, dest, block_migration, host):
+        instance_p = jsonutils.to_primitive(instance)
+        self.cast(ctxt, self.make_msg('live_migration', instance=instance_p,
+                dest=dest, block_migration=block_migration),
+                topic=_compute_topic(self.topic, ctxt, host, None),
+                version='1.40')
+
     def pause_instance(self, ctxt, instance):
         instance_p = jsonutils.to_primitive(instance)
         self.cast(ctxt, self.make_msg('pause_instance',
diff --git a/nova/scheduler/driver.py b/nova/scheduler/driver.py
index 6494957e2..3461ea508 100644
--- a/nova/scheduler/driver.py
+++ b/nova/scheduler/driver.py
@@ -238,11 +238,9 @@ class Scheduler(object):
 
         # Perform migration
         src = instance['host']
-        cast_to_compute_host(context, src, 'live_migration',
-                             update_db=False,
-                             instance_id=instance['id'],
-                             dest=dest,
-                             block_migration=block_migration)
+        self.compute_rpcapi.live_migration(context, host=src,
+                instance=new_instance_ref, dest=dest,
+                block_migration=block_migration)
 
     def _live_migration_src_check(self, context, instance_ref):
         """Live migration check routine (for src host).
diff --git a/nova/tests/compute/test_compute.py b/nova/tests/compute/test_compute.py
index 8561d5124..5c6bc00d4 100644
--- a/nova/tests/compute/test_compute.py
+++ b/nova/tests/compute/test_compute.py
@@ -1663,7 +1663,7 @@ class ComputeTestCase(BaseTestCase):
         self.mox.StubOutWithMock(self.compute.compute_rpcapi,
                                  'pre_live_migration')
         self.compute.compute_rpcapi.pre_live_migration(c,
-                mox.IsA(instance_ref), True, None, instance['host']).AndRaise(
+                mox.IsA(instance), True, None, instance['host']).AndRaise(
                                         rpc.common.RemoteError('', '', ''))
 
         # mocks for rollback
@@ -1687,7 +1687,8 @@ class ComputeTestCase(BaseTestCase):
         self.mox.ReplayAll()
         self.assertRaises(rpc_common.RemoteError,
                           self.compute.live_migration,
-                          c, inst_id, instance['host'], True)
+                          c, dest=instance['host'], block_migration=True,
+                          instance=rpcinst)
 
         # cleanup
         for bdms in db.block_device_mapping_get_all_by_instance(
@@ -1719,7 +1720,8 @@ class ComputeTestCase(BaseTestCase):
 
         # start test
         self.mox.ReplayAll()
-        ret = self.compute.live_migration(c, inst_id, instance['host'])
+        ret = self.compute.live_migration(c, dest=instance['host'],
+                instance=instance)
         self.assertEqual(ret, None)
 
         # cleanup
diff --git a/nova/tests/compute/test_rpcapi.py b/nova/tests/compute/test_rpcapi.py
index ef9064a39..cfd00d505 100644
--- a/nova/tests/compute/test_rpcapi.py
+++ b/nova/tests/compute/test_rpcapi.py
@@ -188,6 +188,11 @@ class ComputeRpcAPITestCase(test.TestCase):
         self._test_compute_api('inject_network_info', 'cast',
                 instance=self.fake_instance, version='1.19')
 
+    def test_live_migration(self):
+        self._test_compute_api('live_migration', 'cast',
+                instance=self.fake_instance, dest='dest',
+                block_migration='blockity_block', host='tsoh', version='1.40')
+
     def test_post_live_migration_at_destination(self):
         self._test_compute_api('post_live_migration_at_destination', 'call',
                 instance=self.fake_instance, block_migration='block_migration',
diff --git a/nova/tests/scheduler/test_scheduler.py b/nova/tests/scheduler/test_scheduler.py
index 3950d1ef6..cfb6d862d 100644
--- a/nova/tests/scheduler/test_scheduler.py
+++ b/nova/tests/scheduler/test_scheduler.py
@@ -409,7 +409,7 @@ class SchedulerTestCase(test.TestCase):
         self.mox.StubOutWithMock(self.driver.compute_rpcapi,
                                  'check_can_live_migrate_destination')
         self.mox.StubOutWithMock(db, 'instance_update_and_get_original')
-        self.mox.StubOutWithMock(driver, 'cast_to_compute_host')
+        self.mox.StubOutWithMock(compute_rpcapi.ComputeAPI, 'live_migration')
         self.mox.StubOutWithMock(notifications, 'send_update')
 
         dest = 'fake_host2'
@@ -431,9 +431,8 @@ class SchedulerTestCase(test.TestCase):
         notifications.send_update(self.context, instance, instance,
                                   service="scheduler")
 
-        driver.cast_to_compute_host(self.context, instance['host'],
-                'live_migration', update_db=False,
-                instance_id=instance['id'], dest=dest,
+        compute_rpcapi.ComputeAPI.live_migration(self.context,
+                host=instance['host'], instance=instance, dest=dest,
                 block_migration=block_migration)
 
         self.mox.ReplayAll()
@@ -451,7 +450,7 @@ class SchedulerTestCase(test.TestCase):
         self.mox.StubOutWithMock(rpc, 'call')
         self.mox.StubOutWithMock(rpc, 'cast')
         self.mox.StubOutWithMock(db, 'instance_update_and_get_original')
-        self.mox.StubOutWithMock(driver, 'cast_to_compute_host')
+        self.mox.StubOutWithMock(compute_rpcapi.ComputeAPI, 'live_migration')
 
         dest = 'fake_host2'
         block_migration = True
@@ -498,9 +497,8 @@ class SchedulerTestCase(test.TestCase):
                 {"task_state": task_states.MIGRATING}).AndReturn(
                         (instance, instance))
 
-        driver.cast_to_compute_host(self.context, instance['host'],
-                'live_migration', update_db=False,
-                instance_id=instance_id, dest=dest,
+        compute_rpcapi.ComputeAPI.live_migration(self.context,
+                host=instance['host'], instance=instance, dest=dest,
                 block_migration=block_migration)
 
         self.mox.ReplayAll()