Fixes bug #709057

* Mark security_group_instance_associations as deleted when instance deleted
* Mark security_group_instance_associations as deleted when security_group deleted
* Make SecurityGroup.instances mapping properly ignore deleted security_group_instance_associations
* Add tests

IMO, this is important to merge.  Nebula has monitoring projects that continually launch and destroy instances, and I imagine other real-world deployments may have similar health checkers.  After a few weeks such health checkers choke due to the inefficient queries related to #709057.

3 files changed, 66 insertions, 11 deletions

diff --git a/nova/db/sqlalchemy/api.py b/nova/db/sqlalchemy/api.py
index 895e7eabe..85250d56e 100644
--- a/nova/db/sqlalchemy/api.py
+++ b/nova/db/sqlalchemy/api.py
@@ -19,6 +19,7 @@
 Implementation of SQLAlchemy backend.
 """
 
+import datetime
 import warnings
 
 from nova import db
@@ -670,8 +671,14 @@ def instance_data_get_for_project(context, project_id):
 def instance_destroy(context, instance_id):
     session = get_session()
     with session.begin():
-        instance_ref = instance_get(context, instance_id, session=session)
-        instance_ref.delete(session=session)
+        session.execute('update instances set deleted=1,'
+                        'deleted_at=:at where id=:id',
+                        {'id': instance_id,
+                         'at': datetime.datetime.utcnow()})
+        session.execute('update security_group_instance_association '
+                        'set deleted=1,deleted_at=:at where instance_id=:id',
+                        {'id': instance_id,
+                         'at': datetime.datetime.utcnow()})
 
 
 @require_context
@@ -1583,6 +1590,11 @@ def security_group_destroy(context, security_group_id):
         # TODO(vish): do we have to use sql here?
         session.execute('update security_groups set deleted=1 where id=:id',
                         {'id': security_group_id})
+        session.execute('update security_group_instance_association '
+                        'set deleted=1,deleted_at=:at '
+                        'where security_group_id=:id',
+                        {'id': security_group_id,
+                         'at': datetime.datetime.utcnow()})
         session.execute('update security_group_rules set deleted=1 '
                         'where group_id=:id',
                         {'id': security_group_id})
diff --git a/nova/db/sqlalchemy/models.py b/nova/db/sqlalchemy/models.py
index c54ebe3ba..7efb36c0e 100644
--- a/nova/db/sqlalchemy/models.py
+++ b/nova/db/sqlalchemy/models.py
@@ -311,10 +311,14 @@ class SecurityGroup(BASE, NovaBase):
                              secondary="security_group_instance_association",
                              primaryjoin='and_('
         'SecurityGroup.id == '
-            'SecurityGroupInstanceAssociation.security_group_id,'
+        'SecurityGroupInstanceAssociation.security_group_id,'
+        'SecurityGroupInstanceAssociation.deleted == False,'
         'SecurityGroup.deleted == False)',
                              secondaryjoin='and_('
         'SecurityGroupInstanceAssociation.instance_id == Instance.id,'
+        # (anthony) the condition below shouldn't be necessary now that the
+        # association is being marked as deleted.  However, removing this
+        # may cause existing deployments to choke, so I'm leaving it
         'Instance.deleted == False)',
                              backref='security_groups')
 
diff --git a/nova/tests/test_compute.py b/nova/tests/test_compute.py
index 09f6ee94a..2aa0690e7 100644
--- a/nova/tests/test_compute.py
+++ b/nova/tests/test_compute.py
@@ -49,7 +49,7 @@ class ComputeTestCase(test.TestCase):
         self.manager = manager.AuthManager()
         self.user = self.manager.create_user('fake', 'fake', 'fake')
         self.project = self.manager.create_project('fake', 'fake', 'fake')
-        self.context = context.get_admin_context()
+        self.context = context.RequestContext('fake', 'fake', False)
 
     def tearDown(self):
         self.manager.delete_user(self.user)
@@ -69,6 +69,13 @@ class ComputeTestCase(test.TestCase):
         inst['ami_launch_index'] = 0
         return db.instance_create(self.context, inst)['id']
 
+    def _create_group(self):
+        values = {'name': 'testgroup',
+                  'description': 'testgroup',
+                  'user_id': self.user.id,
+                  'project_id': self.project.id}
+        return db.security_group_create(self.context, values)
+
     def test_create_instance_defaults_display_name(self):
         """Verify that an instance cannot be created without a display_name."""
         cases = [dict(), dict(display_name=None)]
@@ -82,21 +89,53 @@ class ComputeTestCase(test.TestCase):
 
     def test_create_instance_associates_security_groups(self):
         """Make sure create associates security groups"""
-        values = {'name': 'default',
-                  'description': 'default',
-                  'user_id': self.user.id,
-                  'project_id': self.project.id}
-        group = db.security_group_create(self.context, values)
+        group = self._create_group()
         ref = self.compute_api.create(
                 self.context,
                 instance_type=FLAGS.default_instance_type,
                 image_id=None,
-                security_group=['default'])
+                security_group=['testgroup'])
         try:
             self.assertEqual(len(db.security_group_get_by_instance(
-                self.context, ref[0]['id'])), 1)
+                             self.context, ref[0]['id'])), 1)
+            group = db.security_group_get(self.context, group['id'])
+            self.assert_(len(group.instances) == 1)
+        finally:
+            db.security_group_destroy(self.context, group['id'])
+            db.instance_destroy(self.context, ref[0]['id'])
+
+    def test_destroy_instance_disassociates_security_groups(self):
+        """Make sure destroying disassociates security groups"""
+        group = self._create_group()
+
+        ref = self.compute_api.create(
+                self.context,
+                instance_type=FLAGS.default_instance_type,
+                image_id=None,
+                security_group=['testgroup'])
+        try:
+            db.instance_destroy(self.context, ref[0]['id'])
+            group = db.security_group_get(self.context, group['id'])
+            self.assert_(len(group.instances) == 0)
         finally:
             db.security_group_destroy(self.context, group['id'])
+
+    def test_destroy_security_group_disassociates_instances(self):
+        """Make sure destroying security groups disassociates instances"""
+        group = self._create_group()
+
+        ref = self.compute_api.create(
+                self.context,
+                instance_type=FLAGS.default_instance_type,
+                image_id=None,
+                security_group=['testgroup'])
+
+        try:
+            db.security_group_destroy(self.context, group['id'])
+            group = db.security_group_get(context.get_admin_context(
+                                          read_deleted=True), group['id'])
+            self.assert_(len(group.instances) == 0)
+        finally:
             db.instance_destroy(self.context, ref[0]['id'])
 
     def test_run_terminate(self):