用zmq的pub/sub+flask实现异步通信的研究

zmq_client监听端代码：

#coding=utf8
## client.py
import zmq
import sys
import time
import logging
import os

HOST = '10.1.240.229'#服务器运行的监听地址，需要与服务器运行脚本中设定的监听地址一致，若同一台服务器
PORT = '4444'#服务器运行的监听端口，不可以与对外业务接口相同

logging.basicConfig(filename='subscriber.log', level=logging.INFO)


class ZClient(object):

    def __init__(self, host=HOST, port=PORT):
        """Initialize Worker"""
        self.host = host
        self.port = port
        self._context = zmq.Context()
        self._subscriber = self._context.socket(zmq.SUB)
        print "Client Initiated"
    
    def receive_message(self):
        """Start receiving messages"""
        self._subscriber.connect('tcp://{}:{}'.format(self.host, self.port))
        self._subscriber.setsockopt(zmq.SUBSCRIBE, b"")
    
        while True:
            print 'listening on tcp://{}:{}'.format(self.host, self.port)
            message = self._subscriber.recv()
            time.sleep(1)
            print "sub",message
            time.sleep(100)#可以放置延时非常大的任务
            print "sub",message
            logging.info(
                '{}   - {}'.format(message, time.strftime("%Y-%m-%d %H:%M")))

if __name__ == '__main__':
    zs = ZClient()
    zs.receive_message() 

服务端代码，这里采用flask：

#coding=utf8
# server.py 
import time 
import zmq 
import json
import flask

HOST = '10.1.240.229' #若写成127.0.0.1，则为默认本机ip
PORT = '4444' #监听端口

_context = zmq.Context() 
_publisher = _context.socket(zmq.PUB) 
url = 'tcp://{}:{}'.format(HOST, PORT) 

def publish_message(message):
    try: 
        _publisher.bind(url) 
        time.sleep(1) 
        _publisher.send(message) 
    
    except Exception as e: 
        print "error {}".format(e) 
    finally:
        _publisher.unbind(url) 

from flask import Flask 
from flask import request 
app = Flask(__name__) 

@app.route("/index/", methods=['POST']) 
def lowerString(): 

    received_dict = json.loads(flask.request.data)
    #_strn = request.args.get('param') 
    #response = 'lower case of {} is {}'.format(_strn, _strn.lower()) #将请求转换成小写
    #print received_dict
    response=received_dict
    ret=json.dumps(response)
    publish_message(ret )
    return ret

if __name__ == '__main__': 
    host="10.1.240.202"#对外服务地址
    port = 7001#对外服务端口
    debug = True
    app.run(host, port, debug)

用户访问服务器的对外服务端口时，服务器会进行处理，将部分消息send到一直监听的监听端，然后不需要关心监听端如何处理就给用户端一个消息结果。监听端收到服务端发来的消息后进行处理，处理完毕后进行相应操作。

这种框架一个好处是大大提高服务器的运行效率，不需要等待全部处理完毕后再返回，还有个好处是服务器和监听端可以部署在不同的机器上，可以根据业务需求合理调配硬件资源

要深入的人可以参看http://blog.csdn.net/kwsy2008/article/details/49449781这篇博客以及博主的其他文章

以下附上从http://www.cnblogs.com/rainbowzc/p/3357594.html搬来的原理图