Merge "Reduce db access in prep_resize in the compute manager."

7 files changed, 96 insertions, 45 deletions

diff --git a/nova/compute/manager.py b/nova/compute/manager.py
index 22f30d66b..a8d325b4b 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 = '1.37'
+    RPC_API_VERSION = '1.38'
 
     def __init__(self, compute_driver=None, *args, **kwargs):
         """Load configuration options and connect to the hypervisor."""
@@ -1481,7 +1481,8 @@ class ComputeManager(manager.SchedulerDependentManager):
     @exception.wrap_exception(notifier=notifier, publisher_id=publisher_id())
     @checks_instance_lock
     @wrap_instance_fault
-    def prep_resize(self, context, instance_uuid, instance_type_id, image):
+    def prep_resize(self, context, image, instance=None, instance_uuid=None,
+                    instance_type=None, instance_type_id=None):
         """Initiates the process of moving a running instance to another host.
 
         Possibly changes the RAM and disk size in the process.
@@ -1489,44 +1490,49 @@ class ComputeManager(manager.SchedulerDependentManager):
         """
         context = context.elevated()
 
-        instance_ref = self.db.instance_get_by_uuid(context, instance_uuid)
-        with self.error_out_instance_on_exception(context, instance_uuid):
+        if not instance:
+            instance = self.db.instance_get_by_uuid(context, instance_uuid)
+
+        if not instance_type:
+            instance_type = instance_types.get_instance_type(instance_type_id)
+
+        with self.error_out_instance_on_exception(context, instance['uuid']):
             compute_utils.notify_usage_exists(
-                    context, instance_ref, current_period=True)
+                    context, instance, current_period=True)
             self._notify_about_instance_usage(
-                    context, instance_ref, "resize.prep.start")
+                    context, instance, "resize.prep.start")
 
-            same_host = instance_ref['host'] == FLAGS.host
+            same_host = instance['host'] == FLAGS.host
             if same_host and not FLAGS.allow_resize_to_same_host:
-                self._set_instance_error_state(context, instance_uuid)
+                self._set_instance_error_state(context, instance['uuid'])
                 msg = _('destination same as source!')
                 raise exception.MigrationError(msg)
 
-            old_instance_type_id = instance_ref['instance_type_id']
+            # TODO(russellb): no-db-compute: Send the old instance type info
+            # that is needed via rpc so db access isn't required here.
+            old_instance_type_id = instance['instance_type_id']
             old_instance_type = instance_types.get_instance_type(
                     old_instance_type_id)
-            new_instance_type = instance_types.get_instance_type(
-                    instance_type_id)
 
             migration_ref = self.db.migration_create(context,
-                    {'instance_uuid': instance_ref['uuid'],
-                     'source_compute': instance_ref['host'],
+                    {'instance_uuid': instance['uuid'],
+                     'source_compute': instance['host'],
                      'dest_compute': FLAGS.host,
                      'dest_host': self.driver.get_host_ip_addr(),
                      'old_instance_type_id': old_instance_type['id'],
-                     'new_instance_type_id': instance_type_id,
+                     'new_instance_type_id': instance_type['id'],
                      'status': 'pre-migrating'})
 
-            LOG.audit(_('Migrating'), context=context, instance=instance_ref)
-            self.compute_rpcapi.resize_instance(context, instance_ref,
+            LOG.audit(_('Migrating'), context=context, instance=instance)
+            self.compute_rpcapi.resize_instance(context, instance,
                     migration_ref['id'], image)
 
             extra_usage_info = dict(
-                    new_instance_type=new_instance_type['name'],
-                    new_instance_type_id=new_instance_type['id'])
+                    new_instance_type=instance_type['name'],
+                    new_instance_type_id=instance_type['id'])
 
             self._notify_about_instance_usage(
-                context, instance_ref, "resize.prep.end",
+                context, instance, "resize.prep.end",
                 extra_usage_info=extra_usage_info)
 
     @exception.wrap_exception(notifier=notifier, publisher_id=publisher_id())
diff --git a/nova/compute/rpcapi.py b/nova/compute/rpcapi.py
index aa3d32e34..517cfca4d 100644
--- a/nova/compute/rpcapi.py
+++ b/nova/compute/rpcapi.py
@@ -113,6 +113,10 @@ class ComputeAPI(nova.openstack.common.rpc.proxy.RpcProxy):
                change_instance_metadata()
         1.37 - Remove instance_uuid, add instance argument to
                terminate_instance()
+        1.38 - Changes to prep_resize():
+                - remove instance_uuid, add instance
+                - remove instance_type_id, add instance_type
+                - remove topic, it was unused
     '''
 
     BASE_RPC_API_VERSION = '1.0'
@@ -308,6 +312,14 @@ class ComputeAPI(nova.openstack.common.rpc.proxy.RpcProxy):
                 disk=disk), _compute_topic(self.topic, ctxt, host, None),
                 version='1.23')
 
+    def prep_resize(self, ctxt, image, instance, instance_type, host):
+        instance_p = jsonutils.to_primitive(instance)
+        instance_type_p = jsonutils.to_primitive(instance_type)
+        self.cast(ctxt, self.make_msg('prep_resize',
+                instance=instance_p, instance_type=instance_type_p,
+                image=image), _compute_topic(self.topic, ctxt, host, None),
+                version='1.38')
+
     def reboot_instance(self, ctxt, instance, reboot_type):
         instance_p = jsonutils.to_primitive(instance)
         self.cast(ctxt, self.make_msg('reboot_instance',
diff --git a/nova/scheduler/chance.py b/nova/scheduler/chance.py
index 1be86dda6..0cdcff09e 100644
--- a/nova/scheduler/chance.py
+++ b/nova/scheduler/chance.py
@@ -86,6 +86,7 @@ class ChanceScheduler(driver.Scheduler):
         """Select a target for resize."""
         host = self._schedule(context, 'compute', request_spec,
                               filter_properties)
-        driver.cast_to_compute_host(context, host, 'prep_resize',
-                instance_uuid=instance['uuid'],
-                instance_type_id=instance_type['id'], image=image)
+        updated_instance = driver.instance_update_db(context, instance['uuid'],
+                                                     host.host_state.host)
+        self.compute_rpcapi.prep_resize(context, image, updated_instance,
+                instance_type, host)
diff --git a/nova/scheduler/driver.py b/nova/scheduler/driver.py
index c701d8051..8f98a3ffc 100644
--- a/nova/scheduler/driver.py
+++ b/nova/scheduler/driver.py
@@ -70,15 +70,24 @@ def cast_to_volume_host(context, host, method, update_db=True, **kwargs):
     LOG.debug(_("Casted '%(method)s' to volume '%(host)s'") % locals())
 
 
+def instance_update_db(context, instance_uuid, host):
+    '''Set the host and scheduled_at fields of an Instance.
+
+    :returns: An Instance with the updated fields set properly.
+    '''
+    now = timeutils.utcnow()
+    values = {'host': host, 'scheduled_at': now}
+    return db.instance_update(context, instance_uuid, values)
+
+
 def cast_to_compute_host(context, host, method, update_db=True, **kwargs):
     """Cast request to a compute host queue"""
 
     if update_db:
         instance_uuid = kwargs.get('instance_uuid', None)
-        if instance_uuid is not None:
-            now = timeutils.utcnow()
-            db.instance_update(context, instance_uuid,
-                    {'host': host, 'scheduled_at': now})
+        if instance_uuid:
+            instance_update_db(context, instance_uuid, host)
+
     rpc.cast(context,
              rpc.queue_get_for(context, 'compute', host),
              {"method": method, "args": kwargs})
diff --git a/nova/scheduler/filter_scheduler.py b/nova/scheduler/filter_scheduler.py
index 63405541b..f77acfd19 100644
--- a/nova/scheduler/filter_scheduler.py
+++ b/nova/scheduler/filter_scheduler.py
@@ -118,9 +118,10 @@ class FilterScheduler(driver.Scheduler):
         host = hosts.pop(0)
 
         # Forward off to the host
-        driver.cast_to_compute_host(context, host.host_state.host,
-                'prep_resize', instance_uuid=instance['uuid'],
-                instance_type_id=instance_type['id'], image=image)
+        updated_instance = driver.instance_update_db(context, instance['uuid'],
+                                                     host.host_state.host)
+        self.compute_rpcapi.prep_resize(context, image, updated_instance,
+                instance_type, host.host_state.host)
 
     def _provision_resource(self, context, weighted_host, request_spec,
             reservations, filter_properties, kwargs):
diff --git a/nova/tests/compute/test_compute.py b/nova/tests/compute/test_compute.py
index efb241b75..5d41cd7c6 100644
--- a/nova/tests/compute/test_compute.py
+++ b/nova/tests/compute/test_compute.py
@@ -1146,7 +1146,8 @@ class ComputeTestCase(BaseTestCase):
 
         context = self.context.elevated()
         instance = jsonutils.to_primitive(self._create_fake_instance())
-        self.compute.prep_resize(context, instance['uuid'], 1, {})
+        self.compute.prep_resize(context, instance=instance, instance_type={},
+                                 image={})
         migration_ref = db.migration_get_by_instance_and_status(context,
                 instance['uuid'], 'pre-migrating')
         self.compute.finish_resize(context,
@@ -1167,7 +1168,8 @@ class ComputeTestCase(BaseTestCase):
 
         context = self.context.elevated()
         instance = jsonutils.to_primitive(self._create_fake_instance())
-        self.compute.prep_resize(context, instance['uuid'], 1, {})
+        self.compute.prep_resize(context, instance=instance, instance_type={},
+                                 image={})
         migration_ref = db.migration_get_by_instance_and_status(context,
                 instance['uuid'], 'pre-migrating')
 
@@ -1250,12 +1252,14 @@ class ComputeTestCase(BaseTestCase):
         context = self.context.elevated()
         old_type_id = instance_types.get_instance_type_by_name(
                                                 'm1.tiny')['id']
-        new_type_id = instance_types.get_instance_type_by_name(
-                                                'm1.small')['id']
+        new_type = instance_types.get_instance_type_by_name('m1.small')
+        new_type = jsonutils.to_primitive(new_type)
+        new_type_id = new_type['id']
         self.compute.run_instance(self.context, instance['uuid'])
 
         db.instance_update(self.context, instance['uuid'], {'host': 'foo'})
-        self.compute.prep_resize(context, instance['uuid'], new_type_id, {})
+        self.compute.prep_resize(context, instance=instance,
+                instance_type=new_type, image={})
         migration_ref = db.migration_get_by_instance_and_status(context,
                                                 instance['uuid'],
                                                 'pre-migrating')
@@ -1304,7 +1308,9 @@ class ComputeTestCase(BaseTestCase):
         test_notifier.NOTIFICATIONS = []
 
         db.instance_update(self.context, instance['uuid'], {'host': 'foo'})
-        self.compute.prep_resize(context, instance['uuid'], 1, {})
+        self.compute.prep_resize(context,
+                instance=jsonutils.to_primitive(instance),
+                instance_type={}, image={})
         db.migration_get_by_instance_and_status(context,
                                                 instance['uuid'],
                                                 'pre-migrating')
@@ -1343,12 +1349,15 @@ class ComputeTestCase(BaseTestCase):
         context = self.context.elevated()
 
         self.compute.run_instance(self.context, instance['uuid'])
-        db.instance_update(self.context, instance['uuid'], {'host': 'foo'})
+        new_instance = db.instance_update(self.context, instance['uuid'],
+                                          {'host': 'foo'})
 
         self.assertRaises(exception.MigrationError, self.compute.prep_resize,
-                          context, instance['uuid'], 1, {})
+                          context,
+                          instance=jsonutils.to_primitive(new_instance),
+                          instance_type={}, image={})
         self.compute.terminate_instance(context,
-            instance=jsonutils.to_primitive(instance))
+            instance=jsonutils.to_primitive(new_instance))
 
     def test_resize_instance_driver_error(self):
         """Ensure instance status set to Error on resize error"""
@@ -1364,7 +1373,8 @@ class ComputeTestCase(BaseTestCase):
 
         self.compute.run_instance(self.context, instance['uuid'])
         db.instance_update(self.context, instance['uuid'], {'host': 'foo'})
-        self.compute.prep_resize(context, instance['uuid'], 1, {})
+        self.compute.prep_resize(context, instance=instance,
+                                 instance_type={}, image={})
         migration_ref = db.migration_get_by_instance_and_status(context,
                 instance['uuid'], 'pre-migrating')
 
@@ -1385,7 +1395,8 @@ class ComputeTestCase(BaseTestCase):
         self.compute.run_instance(self.context, instance['uuid'])
         db.instance_update(self.context, instance['uuid'],
                            {'host': 'foo'})
-        self.compute.prep_resize(context, instance['uuid'], 1, {})
+        self.compute.prep_resize(context, instance=instance,
+                instance_type={}, image={})
         migration_ref = db.migration_get_by_instance_and_status(context,
                 instance['uuid'], 'pre-migrating')
         self.compute.resize_instance(context, migration_ref['id'], {},
@@ -1413,11 +1424,14 @@ class ComputeTestCase(BaseTestCase):
                 inst_ref['instance_type_id'])
         self.assertEqual(instance_type_ref['flavorid'], '1')
 
-        db.instance_update(self.context, instance['uuid'], {'host': 'foo'})
+        new_inst_ref = db.instance_update(self.context, instance['uuid'],
+                                          {'host': 'foo'})
 
         new_instance_type_ref = db.instance_type_get_by_flavor_id(context, 3)
-        self.compute.prep_resize(context, inst_ref['uuid'],
-                                 new_instance_type_ref['id'], {})
+        self.compute.prep_resize(context,
+                instance=jsonutils.to_primitive(new_inst_ref),
+                instance_type=jsonutils.to_primitive(new_instance_type_ref),
+                image={})
 
         migration_ref = db.migration_get_by_instance_and_status(context,
                 inst_ref['uuid'], 'pre-migrating')
@@ -1465,7 +1479,9 @@ class ComputeTestCase(BaseTestCase):
         self.compute.run_instance(self.context, instance['uuid'])
         instance = db.instance_get_by_uuid(self.context, instance['uuid'])
         self.assertRaises(exception.MigrationError, self.compute.prep_resize,
-                self.context, instance['uuid'], 1, {})
+                self.context,
+                instance=jsonutils.to_primitive(instance),
+                instance_type={}, image={})
         self.compute.terminate_instance(self.context,
                 instance=jsonutils.to_primitive(instance))
 
@@ -1482,7 +1498,8 @@ class ComputeTestCase(BaseTestCase):
 
         self.compute.run_instance(self.context, inst_ref['uuid'])
         db.instance_update(self.context, inst_ref['uuid'], {'host': 'foo'})
-        self.compute.prep_resize(context, inst_ref['uuid'], 1, {})
+        self.compute.prep_resize(context, instance=inst_ref, instance_type={},
+                                 image={})
         migration_ref = db.migration_get_by_instance_and_status(context,
                 inst_ref['uuid'], 'pre-migrating')
         self.assertRaises(test.TestingException, self.compute.resize_instance,
diff --git a/nova/tests/compute/test_rpcapi.py b/nova/tests/compute/test_rpcapi.py
index a1062ea57..94b44b345 100644
--- a/nova/tests/compute/test_rpcapi.py
+++ b/nova/tests/compute/test_rpcapi.py
@@ -210,6 +210,11 @@ class ComputeRpcAPITestCase(test.TestCase):
                 instance=self.fake_instance, block_migration='block_migration',
                 disk='disk', host='host', version='1.23')
 
+    def test_prep_resize(self):
+        self._test_compute_api('prep_resize', 'cast',
+                instance=self.fake_instance, instance_type='fake_type',
+                image='fake_image', host='host', version='1.38')
+
     def test_reboot_instance(self):
         self._test_compute_api('reboot_instance', 'cast',
                 instance=self.fake_instance, reboot_type='type', version='1.4')