如何知道服务器是否在python请求模块中关闭连接

Question

I am using python requests module in order to generate the traffic to my web server,

After certain request connection suppose to break and I want to run some callback if connection got closed( maybe server is sending the FIN or RESET flag).

How can I find if server or closing the connection in Requests module, I don't want to use tcpdump or any packet capturing utility to verify that.

 82     def request_per_session(self, request, method='post', page=None,**options):
 83         url=self.url
 84         if page:url+=page
 85         print pprint.pprint(options)
 86         s = requests.Session()
 87         httpmethodToCall = getattr(s, method)
 88         print pprint.pprint(httpmethodToCall)
 89         for n in range(request):
 90             print "running %d" %n
 91             if method == 'get':
 92                 r=httpmethodToCall(url)
 93             else:
 94                 r=httpmethodToCall(url,options)
 95             print r.status_code

Answer 1

This can be more effectively accomplished with a port scanner.

To elaborate, I'm assuming you are sending/receiving data on port 80. With this information, merely create a socket, try to connect to the given host, and if there is an error you can either pass back the exception or print it out. For example:

import socket

def checkServer(server):
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    try:
        socket.connect((socket.gethostbyname(server), 80))
        return None
    except socket.error as e:
        return e

In this code, if there is no error, then nothing is passed back(in the form of None ), but if there is an error, the exception object is passed back. The code is a lot cleaner than using the Requests module because it deals with low-level connections, which are great if you want to check if things are open, passing data, and so on, but are terrible for sending data, scraping webpages, and so on. Something like urllib2 or requests would be better suited for that.

I hope this helps.