Merge "Provide config option to cap events per stack"

etc/heat/heat.conf.sample

@@ -39,6 +39,17 @@
 # one time. (integer value)
 #max_stacks_per_tenant=100
 
+# Controls how many events will be pruned whenever a  stack's
+# events exceed max_events_per_stack. Set this lower to keep
+# more events at the expense of more frequent purges. (integer
+# value)
+#event_purge_batch_size=10
+
+# Maximum events that will be available per stack. Older
+# events will be deleted when this is reached. Set to 0 for
+# unlimited events per stack. (integer value)
+#max_events_per_stack=1000
+
 # Name of the engine node. This can be an opaque identifier.It
 # is not necessarily a hostname, FQDN, or IP address. (string
 # value)

heat/common/config.py

@@ -104,9 +104,18 @@ engine_opts = [
     cfg.IntOpt('max_stacks_per_tenant',
                default=100,
                help=_('Maximum number of stacks any one tenant may have'
-                      ' active at one time.'))]
+                      ' active at one time.')),
-
+    cfg.IntOpt('event_purge_batch_size',
-
+               default=10,
+               help=_('Controls how many events will be pruned whenever a '
+                      ' stack\'s events exceed max_events_per_stack. Set this'
+                      ' lower to keep more events at the expense of more'
+                      ' frequent purges.')),
+    cfg.IntOpt('max_events_per_stack',
+               default=1000,
+               help=_('Maximum events that will be available per stack. Older'
+                      ' events will be deleted when this is reached. Set to 0'
+                      ' for unlimited events per stack.'))]
 rpc_opts = [
     cfg.StrOpt('host',
                default=socket.gethostname(),

heat/db/sqlalchemy/api.py

@@ -17,9 +17,12 @@
 from datetime import datetime
 from datetime import timedelta
 
+from oslo.config import cfg
 import sqlalchemy
 from sqlalchemy.orm.session import Session
 
+cfg.CONF.import_opt('max_events_per_stack', 'heat.common.config')
+
 from heat.openstack.common.gettextutils import _
 
 from heat.common import crypt
@@ -341,7 +344,35 @@ def event_count_all_by_stack(context, stack_id):
     return _query_all_by_stack(context, stack_id).count()
 
 
+def _delete_event_rows(context, stack_id, limit):
+    # MySQL does not support LIMIT in subqueries,
+    # sqlite does not support JOIN in DELETE.
+    # So we must manually supply the IN() values.
+    # pgsql SHOULD work with the pure DELETE/JOIN below but that must be
+    # confirmed via integration tests.
+    query = _query_all_by_stack(context, stack_id)
+    session = _session(context)
+    if 'postgres' not in session.connection().dialect.name:
+        ids = [r.id for r in query.order_by(
+            models.Event.id).limit(limit).all()]
+        q = session.query(models.Event).filter(
+            models.Event.id.in_(ids))
+    else:
+        stmt = session.query(
+            models.Event.id).filter_by(
+                stack_id=stack_id).order_by(
+                    models.Event.id).limit(limit).subquery()
+        q = query.join(stmt, models.Event.id == stmt.c.id)
+    return q.delete(synchronize_session='fetch')
+
+
 def event_create(context, values):
+    if 'stack_id' in values and cfg.CONF.max_events_per_stack:
+        if ((event_count_all_by_stack(context, values['stack_id']) >=
+             cfg.CONF.max_events_per_stack)):
+            # prune
+            _delete_event_rows(
+                context, values['stack_id'], cfg.CONF.event_purge_batch_size)
     event_ref = models.Event()
     event_ref.update(values)
     event_ref.save(_session(context))

heat/tests/test_event.py

@@ -12,6 +12,10 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from oslo.config import cfg
+
+cfg.CONF.import_opt('event_purge_batch_size', 'heat.common.config')
+cfg.CONF.import_opt('max_events_per_stack', 'heat.common.config')
 
 import heat.db.api as db_api
 from heat.engine import parser
@@ -100,6 +104,25 @@ class EventTest(HeatTestCase):
         self.assertNotEqual(None, loaded_e.timestamp)
         self.assertEqual({'Foo': 'goo'}, loaded_e.resource_properties)
 
+    def test_store_caps_events(self):
+        cfg.CONF.set_override('event_purge_batch_size', 1)
+        cfg.CONF.set_override('max_events_per_stack', 1)
+        self.resource.resource_id_set('resource_physical_id')
+
+        e = event.Event(self.ctx, self.stack, 'TEST', 'IN_PROGRESS', 'Testing',
+                        'alabama', self.resource.properties,
+                        self.resource.name, self.resource.type())
+        e.store()
+        self.assertEquals(1, len(db_api.event_get_all_by_stack(self.ctx,
+                                                               self.stack.id)))
+        e = event.Event(self.ctx, self.stack, 'TEST', 'IN_PROGRESS', 'Testing',
+                        'arizona', self.resource.properties,
+                        self.resource.name, self.resource.type())
+        e.store()
+        events = db_api.event_get_all_by_stack(self.ctx, self.stack.id)
+        self.assertEquals(1, len(events))
+        self.assertEqual('arizona', events[0].physical_resource_id)
+
     def test_identifier(self):
         e = event.Event(self.ctx, self.stack, 'TEST', 'IN_PROGRESS', 'Testing',
                         'wibble', self.resource.properties,