Request-reply broker in Python

Table of Contents

# Simple request-reply broker
#
# Author: Lev Givon <lev(at)columbia(dot)edu>

import zmq

# Prepare our context and sockets
context = zmq.Context()
frontend = context.socket(zmq.ROUTER)
backend = context.socket(zmq.DEALER)
frontend.bind("tcp://*:5559")
backend.bind("tcp://*:5560")

# Initialize poll set
poller = zmq.Poller()
poller.register(frontend, zmq.POLLIN)
poller.register(backend, zmq.POLLIN)

# Switch messages between sockets
while True:
socks = dict(poller.poll())

if socks.get(frontend) == zmq.POLLIN:
message = frontend.recv()
more = frontend.getsockopt(zmq.RCVMORE)
if more:
backend.send(message, zmq.SNDMORE)
else:
backend.send(message)

if socks.get(backend) == zmq.POLLIN:
message = backend.recv()
more = backend.getsockopt(zmq.RCVMORE)
if more:
frontend.send(message, zmq.SNDMORE)
else:
frontend.send(message)