CODEWITHSUNDEEP
pythondnsip-address
Jason S
Jason S

Reputation: 189626

python socket.gethostbyaddr() -- reduce timeout?

socket.gethostbyname() works great when its argument is a real hostname. But when it's a nonexistent host, I get a 3 second timeout followed by 

socket.gaierror: [Errno 11001] getaddrinfo failed

I don't mind the exception (it's appropriate), but is there any way to reduce the timeout?

Upvotes: 6

Views: 3967

Answers (3)

Yehla
Yehla

Reputation: 191

I'm quite new to threading but I tried implementing @Andriy Tylychko's suggestion of using threads.

from threading import Thread
import time

def is_ip_connected(IP, timeout=2):
    ans = {"success": False}

    def _is_ip_connected(IP, ans):
        try:
            socket.gethostbyaddr(IP)
            ans["success"] = True
        except:
            pass

    time_thread = Thread(target=time.sleep, args=(timeout,))
    IP_thread = Thread(target=_is_ip_connected,  kwargs={"IP": IP, "ans": ans})

    time_thread.start()
    IP_thread.start()

    while time_thread.is_alive() and IP_thread.is_alive():
        pass

    return(ans["success"])


print(is_ip_connected(IP="192.168.1.202"))

Upvotes: 0

GuruOfAll007
GuruOfAll007

Reputation: 37

A simple solution after going through this would be:

import socket
socket.setdefaulttimeout(5) #Default this is 30
socket.gethostbyname(your_url)

Upvotes: 3

Andriy Tylychko
Andriy Tylychko

Reputation: 16256

This can be impossible if Python uses system gethostbyname(). I'm not sure you really want this because you can receive false timeouts.

Once I had a similar problem, but from C++: I had to call the function for large number of names, so long timeout was a real pain. A solution was to call it from many threads in parallel, so while some of them was stuck waiting for timeout, all others were proceeding fine.

Upvotes: 1

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