ZMQ通信协议小结

ZMQ 通信协议小结

• 前言

  项目中涉及到 zmq通信协议相关内容，所以将学习、使用过程同步分享，
  Talk is cheap, Show me the cod, 通篇以代码分享为主，且本文对底层socket不做过多叙述，以实际应用为准，希望能帮到各位！

• zmq的三种模型

  1、Request_Reply模式(请求——应答): REP、 REQ

  	一发一收 无缓存 断开连接数据丢失。
  	 双向消息，REP端负责send消息，必须recv到REQ的返回，否则通道堵塞
  

  伪代码

  # 1、Request_Reply模式
  # server
  import zmq
  
  context = zmq.Context()
  socket = context.socket(zmq.REP)
  socket.bind('tcp://*:5556')
  
  while True:
      message = socket.recv()
      print(message)
      socket.send('server response')
  ----------------------------------------------------------
  # client 
  import zmq
  import sys
  
  context = zmq.Context()
  socket = context.socket(zmq.REQ)
  socket.connect('tcp://localhost:5556')
  
  while True:
      data = raw_input('input your data:')
      if data == 'q':
          sys.exit()
      socket.send(data)
      response = socket.recv()
      print(response)
  
  

  应用场景

  场景说明： 我们定义一个非阻塞 的消息通道， 用作发送特定的Python结构体数据，包含三个文件如下:

  1.server.py

  import time
  import zmq
  from data import zmqStruct
  
  context = zmq.Context()
  socket = context.socket(zmq.REP)
  socket.bind("tcp://ip:5656")
  
  while True:
      try:
          message = socket.recv_pyobj(zmq.NOBLOCK)
          print(message)
          #time.sleep(1)
          socket.send_pyobj('123123123')
      except zmq.Again as e:
          if e.erron!=zmq.EAGAIN:
              print(repr(e))
  
      time.sleep(1)
  

  2.client.py

  from data import zmqStruct
  
  def zmqREQ():
      import zmq
      context = zmq.Context()
      socket = context.socket(zmq.REQ)
      socket.connect("tcp://{}:5656".format('192.168.24.107'))
      return socket
  
  sendStruct = zmqStruct()
  zmqClient = zmqREQ()
  zmqClient.send_pyobj(sendStruct)
  print zmqClient.recv_pyobj()
  
  

  3.data.py

  class zmqStruct(onject):  # 消息结构体
  	def __init__(self, cmd=0, data=None, desc=''):
          self.cmd = cmd
          self.data = data
          self.desc = desc
  

  2、Publish-Subscribe模式(发布——订阅): PUB、SUB

  	广播所有client,无缓存，断开连接数据丢失。
  	发布端发布主题topic,订阅端只会收到已订阅的主题topic
  

  伪代码

  # 2、Publish-Subscribe模式
  # server
  import zmq
  
  context = zmq.Context()
  socket = context.socket(zmq.PUB)
  socket.bind("tcp://*:5005")
  while True:
      msg = input('input your data:').encode('utf-8')
      socket.send(msg)
  ------------------------------------------------------------------
  # client
  import zmq
  
  context = zmq.Context()
  socket = context.socket(zmq.SUB)
  socket.connect('tcp://127.0.0.1:5005')
  # 使用socket.setsockopt()进行过滤
  socket.setsockopt(zmq.SUBSCRIBE,b'')
  while True:
      print(socket.recv_string())
  

  应用场景

  场景说明

  Code

  Error

  3、Parallel Pipeline模式(push——pull): PUSH、PULL

  	>>可以由三部分组成：push推送数据，work缓存数据，pull竞争数据，断开连接数据不丢失，重连继续发送。work中间件可以去掉
  	>> 单向通道，push的消息，只能有一个pull端进行接收
  

  伪代码

  # 3、Parallel Pipeline模式
  # server
  import zmq
  
  context = zmq.Context()
  socket = context.socket(zmq.PULL)
  socket.bind('tcp://*:5566')
  while True:
      data = socket.recv()
      print(data)
  ---------------------------------------------
  # work   无work  push 会阻塞掉
  import zmq
  
  context = zmq.Context()
  
  recive = context.socket(zmq.PULL)
  recive.connect('tcp://127.0.0.1:5565')
  sender = context.socket(zmq.PUSH)
  sender.connect('tcp://127.0.0.1:5566')
  
  while True:
      data = recive.recv()
      sender.send(data)
  ---------------------------------------------
  # client
  import zmq
  import time
  
  context = zmq.Context()
  socket = context.socket(zmq.PUSH)
  
  socket.bind('tcp://*:5565')
  
  while True:
      data = raw_input('input your data:')
      socket.send(data)
  

  应用场景

  场景说明

  Code

  Error