CODEWITHSUNDEEP
pythonpython-3.xsockets
fluk3_
fluk3_

Reputation: 1

Python Socket Auto Reconnect

I'm a beginner in Python. So I wanted to make if a server shuts down, disconnects, the client just keeps connecting until the server is opened again. I get this error:
File "C:\Users\Laurynas\Desktop\project\client.py", line 24, in reconnect server1.connect((HOST, PORT)) OSError: [WinError 10056] A connect request was made on an already connected socket
Current client.py code:

import socket
import time
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server1 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)


HOST = socket.gethostbyname(socket.gethostname())
PORT = 8888

# Check at the first try
def connect():
    try:
        server.connect((HOST, PORT))
        messages()
    except ConnectionRefusedError:
        print("reconnecting, please wait...")
        time.sleep(0.1)
        connect()

# Check at the second, third, etc.
def reconnect():
    try:
        server1.connect((HOST, PORT))
        messages()
    except ConnectionRefusedError:
        print("reconnecting, please wait...")
        time.sleep(0.1)
        reconnect()
        

def messages():
    while True:
        try:
            command = server.recv(1024).decode()
            print(command)
        except:
            reconnect()
            pass
connect()

Upvotes: 0

Views: 2116

Answers (1)

tdelaney
tdelaney

Reputation: 77407

With the exception of listening sockets that are used for many accepts, data sockets cannot be reconnected and reused. On the client side a new socket needs to be created for the new connection and on the server side a new accept needs to be made. The old sockets should also be closed to get them out of the kernel.

This poses a difficulty because a server won't automatically know which client is reconnecting and which higher level activity should be restarted. This has to be baked into the protocol you implement on top of the connection. In HTTP for instance, each GET/PUT/POST reidentifies itself so that the web server knows how to do that, perhaps using a cookie based session id.

Bottom line, you can't keep on calling server.connect to start it up again.

Upvotes: 1

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