Example dns_mass_resolve.py¶
1#!/usr/bin/python
2# gevent-test-requires-resource: network
3"""Resolve hostnames concurrently, exit after 2 seconds.
4
5Under the hood, this might use an asynchronous resolver based on
6c-ares (the default) or thread-pool-based resolver.
7
8You can choose between resolvers using GEVENT_RESOLVER environment
9variable. To enable threading resolver:
10
11 GEVENT_RESOLVER=thread python dns_mass_resolve.py
12"""
13from __future__ import print_function
14import gevent
15from gevent import socket
16from gevent.pool import Pool
17
18N = 1000
19# limit ourselves to max 10 simultaneous outstanding requests
20pool = Pool(10)
21finished = 0
22
23
24def job(url):
25 global finished
26 try:
27 try:
28 ip = socket.gethostbyname(url)
29 print('%s = %s' % (url, ip))
30 except socket.gaierror as ex:
31 print('%s failed with %s' % (url, ex))
32 finally:
33 finished += 1
34
35with gevent.Timeout(2, False):
36 for x in range(10, 10 + N):
37 pool.spawn(job, '%s.com' % x)
38 pool.join()
39
40print('finished within 2 seconds: %s/%s' % (finished, N))