quiescent pool state tests

tests for in_flight == 0 after various cluster operations
related to PYTHON-195

also changes pool.get_state to return a dict of properties (instead of a
string) for easier testing

cassandra/pool.py

@@ -366,9 +366,10 @@ class HostConnection(object):
         return [c] if c else []
 
     def get_state(self):
-        have_conn = self._connection is not None
-        in_flight = self._connection.in_flight if have_conn else 0
-        return "shutdown: %s, open: %s, in_flights: %s" % (self.is_shutdown, have_conn, in_flight)
+        connection = self._connection
+        open_count = 1 if connection and not (connection.is_closed or connection.is_defunct) else 0
+        in_flights = [connection.in_flight] if connection else []
+        return {'shutdown': self.is_shutdown, 'open_count': open_count, 'in_flights': in_flights}
 
 
 _MAX_SIMULTANEOUS_CREATION = 1
@@ -703,5 +704,5 @@ class HostConnectionPool(object):
         return self._connections
 
     def get_state(self):
-        in_flights = ", ".join([str(c.in_flight) for c in self._connections])
-        return "shutdown: %s, open_count: %d, in_flights: %s" % (self.is_shutdown, self.open_count, in_flights)
+        in_flights = [c.in_flight for c in self._connections]
+        return {'shutdown': self.is_shutdown, 'open_count': self.open_count, 'in_flights': in_flights}

tests/integration/standard/test_cluster.py

@@ -31,6 +31,7 @@ from cassandra.policies import (RoundRobinPolicy, ExponentialReconnectionPolicy,
 from cassandra.query import SimpleStatement, TraceUnavailable
 
 from tests.integration import use_singledc, PROTOCOL_VERSION, get_server_versions
+from tests.integration.util import assert_quiescent_pool_state
 
 
 def setup_module():
@@ -495,6 +496,10 @@ class ClusterTests(unittest.TestCase):
         self.assertIn(cluster.control_connection, holders)
         self.assertEqual(len(holders), len(cluster.metadata.all_hosts()) + 1)  # hosts pools, 1 for cc
 
+        cluster._idle_heartbeat.stop()
+        cluster._idle_heartbeat.join()
+        assert_quiescent_pool_state(self, cluster)
+
         session.shutdown()
 
     @patch('cassandra.cluster.Cluster.idle_heartbeat_interval', new=0.1)
@@ -515,3 +520,39 @@ class ClusterTests(unittest.TestCase):
         self.assertFalse(any(c.is_idle for c in connections))
 
         session.shutdown()
+
+    def test_pool_management(self):
+        # Ensure that in_flight and request_ids quiesce after cluster operations
+        cluster = Cluster(protocol_version=PROTOCOL_VERSION, idle_heartbeat_interval=0)  # no idle heartbeat here, pool management is tested in test_idle_heartbeat
+        session = cluster.connect()
+        session2 = cluster.connect()
+
+        # prepare
+        p = session.prepare("SELECT * FROM system.local WHERE key=?")
+        self.assertTrue(session.execute(p, ('local',)))
+
+        # simple
+        self.assertTrue(session.execute("SELECT * FROM system.local WHERE key='local'"))
+
+        # set keyspace
+        session.set_keyspace('system')
+        session.set_keyspace('system_traces')
+
+        # use keyspace
+        session.execute('USE system')
+        session.execute('USE system_traces')
+
+        # refresh schema
+        cluster.refresh_schema()
+        cluster.refresh_schema(max_schema_agreement_wait=0)
+
+        # submit schema refresh
+        future = cluster.submit_schema_refresh()
+        future.result()
+
+        assert_quiescent_pool_state(self, cluster)
+
+        session2.shutdown()
+        del session2
+        assert_quiescent_pool_state(self, cluster)
+        session.shutdown()

tests/integration/util.py

@@ -0,0 +1,24 @@
+# Copyright 2013-2014 DataStax, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+def assert_quiescent_pool_state(test_case, cluster):
+
+    for session in cluster.sessions:
+        pool_states = session.get_pool_state().values()
+        test_case.assertTrue(pool_states)
+
+        for state in pool_states:
+            test_case.assertFalse(state['shutdown'])
+            test_case.assertGreater(state['open_count'], 0)
+            test_case.assertTrue(all((i == 0 for i in state['in_flights'])))