Non-blocking outgoing queue was implemented

The main issue with eventlet.green.zmq is that libzmq as a C-library
is completely monkey-patch unfriendly. So any blocking call inside
the native library makes calling process stuck. We can't avoid this
actually in an absolutely normal situation when a client appears
earlier than listener we have all client process get stuck until listener
raised. If the listener for example is also blocked awaiting for some
other service to appear we have a chain of locks which may occasionally
result in a dead-lock. The other situation with Notifier is quite similar.

For that reason zmq-broker was restored, but now it serves as an outgoing
queue on a client side. Servers remained the same dynamically port-binded.
Now all clients can still use green-zmq, but presence of the broker-queue
on a host guarantees that green threads will never blocked in a client
because all messages will wait their listeners inside the broker queue.
The broker process's modules are not monkey-patched, they make use of native
threading and native zmq.

Possibility to run without broker also remains. The option zmq_use_broker
introduced for that reason.

Closes-Bug: #1497315

Change-Id: I786b100fd6ee1cf4b99139db0ca044d358d36345

1 files changed, 1 insertions, 1 deletions

diff --git a/setup.cfg b/setup.cfg
index f584e21..b50372e 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -22,7 +22,7 @@ packages =
 
 [entry_points]
 console_scripts =
-    oslo-messaging-zmq-receiver = oslo_messaging._cmd.zmq_receiver:main
+    oslo-messaging-zmq-broker = oslo_messaging._cmd.zmq_broker:main
 
 oslo.messaging.drivers =
     rabbit = oslo_messaging._drivers.impl_rabbit:RabbitDriver