20170701_python之tcp自动重连.rst

python之tcp自动重连

操作系统： CentOS 6.9_x64

python语言版本： 2.7.13

问题描述

现有一个tcp客户端程序，需定期从服务器取数据，但由于种种原因（网络不稳定等）需要自动重连。

测试服务器示例代码：

#! /usr/bin/env python
#-*- coding:utf-8 -*-

import socket
import threading

class ThreadedServer(object):
    def __init__(self, host, port):
        self.host = host
        self.port = port
        self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        self.sock.bind((self.host, self.port))

    def listen(self):
        self.sock.listen(5)
        while True:
            client, address = self.sock.accept()
            client.settimeout(60)
            threading.Thread(target = self.listenToClient,args = (client,address)).start()

    def listenToClient(self, client, address):
        size = 1024
        while True:
            try:
                data = client.recv(size)
                if data:
                    response = data
                    client.send(response)
                    print "secndLen: ",len(data)
                else:
                    raise error('Client disconnected')
            except:
                client.close()
                return False

if __name__ == "__main__":
    while True:
        port_num = 12345
        try:
            port_num = int(port_num)
            break
        except ValueError:
            pass

    ThreadedServer('',port_num).listen()

解决方案

'''
tcp client with reconnect
E-Mail : Mike_Zhang@live.com
'''

#! /usr/bin/env python
#-*- coding:utf-8 -*-

import os,sys,time
import socket

def doConnect(host,port):
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    try :
        sock.connect((host,port))
    except :
        pass
    return sock

def main():
    host,port = "127.0.0.1",12345
    print host,port
    sockLocal = doConnect(host,port)

    while True :
        try :
            msg = str(time.time())
            sockLocal.send(msg)
            print "send msg ok : ",msg
            print "recv data :",sockLocal.recv(1024)
        except socket.error :
            print "\r\nsocket error,do reconnect "
            time.sleep(3)
            sockLocal = doConnect(host,port)
        except :
            print '\r\nother error occur '
            time.sleep(3)
        time.sleep(1)

if __name__ == "__main__" :
    main()

运行效果：

(py27env) [root@local t1]# python tcpClient1_reconnect.py
127.0.0.1 12345
send msg ok :  1498891374.98
recv data : 1498891374.98
send msg ok :  1498891375.98
recv data : 1498891375.98
send msg ok :  1498891376.98
recv data :

socket error,do reconnect
send msg ok :  1498891381.99
recv data : 1498891381.99
send msg ok :  1498891382.99
recv data : 1498891382.99

讨论

这里只是个简单的示例代码，实现了python的tcp自动重连。