Clear out RPC connection pool before exit.

Fixes bug 767984.

This patch ensures that pooled connections to a messaging system get
cleaned up before a process that has used the RPC API exits.

Change-Id: I56eca54334075378534a7a5d3434c420319672b4

bin/nova-dhcpbridge

@@ -125,5 +125,8 @@ def main():
 
         print init_leases(network_id)
 
+    rpc.cleanup()
+
+
 if __name__ == "__main__":
     main()

bin/nova-manage

@@ -2354,6 +2354,7 @@ def main():
     # call the action with the remaining arguments
     try:
         fn(*fn_args, **fn_kwargs)
+        rpc.cleanup()
         sys.exit(0)
     except TypeError:
         print _("Possible wrong number of arguments supplied")

nova/rpc/__init__.py

@@ -139,6 +139,19 @@ def notify(context, topic, msg):
     return _get_impl().notify(context, topic, msg)
 
 
+def cleanup():
+    """Clean up resoruces in use by implementation.
+
+    Clean up any resources that have been allocated by the RPC implementation.
+    This is typically open connections to a messaging service.  This function
+    would get called before an application using this API exits to allow
+    connections to get torn down cleanly.
+
+    :returns: None
+    """
+    return _get_impl().cleanup()
+
+
 _RPCIMPL = None
 
 

nova/rpc/amqp.py

@@ -127,6 +127,11 @@ def __getattr__(self, key):
         else:
             raise exception.InvalidRPCConnectionReuse()
 
+    @classmethod
+    def empty_pool(cls):
+        while cls._connection_pool.free_items:
+            cls._connection_pool.get().close()
+
 
 def msg_reply(msg_id, reply=None, failure=None, ending=False):
     """Sends a reply or an error on the channel signified by msg_id.
@@ -353,3 +358,7 @@ def notify(context, topic, msg):
     pack_context(msg, context)
     with ConnectionContext() as conn:
         conn.notify_send(topic, msg)
+
+
+def cleanup():
+    ConnectionContext.empty_pool()

nova/rpc/impl_carrot.py

@@ -635,6 +635,10 @@ def notify(context, topic, msg):
         publisher.close()
 
 
+def cleanup():
+    pass
+
+
 def generic_response(message_data, message):
     """Logs a result and exits."""
     LOG.debug(_('response %s'), message_data)

nova/rpc/impl_fake.py

@@ -136,6 +136,10 @@ def notify(context, topic, msg):
     pass
 
 
+def cleanup():
+    pass
+
+
 def fanout_cast(context, topic, msg):
     """Cast to all consumers of a topic"""
     method = msg.get('method')

nova/rpc/impl_kombu.py

@@ -618,3 +618,7 @@ def fanout_cast(context, topic, msg):
 def notify(context, topic, msg):
     """Sends a notification event on a topic."""
     return rpc_amqp.notify(context, topic, msg)
+
+
+def cleanup():
+    return rpc_amqp.cleanup()

nova/rpc/impl_qpid.py

@@ -506,3 +506,7 @@ def fanout_cast(context, topic, msg):
 def notify(context, topic, msg):
     """Sends a notification event on a topic."""
     return rpc_amqp.notify(context, topic, msg)
+
+
+def cleanup():
+    return rpc_amqp.cleanup()

nova/service.py

@@ -414,3 +414,4 @@ def wait():
         _launcher.wait()
     except KeyboardInterrupt:
         _launcher.stop()
+    rpc.cleanup()