Unable to run a simple tornado server

[harveypham]

In bash shell, install python-pip:
sudo apt-get install python-pip

Install tornado:
sudo pip install tornado

Create a tornado server, server.py with the following content:

import tornado.ioloop
import tornado.web
ioloop = tornado.ioloop.IOLoop.instance()

class MainHandler(tornado.web.RequestHandler):
    def get(self):
        self.write("Hello, world")

application = tornado.web.Application([
    (r"/", MainHandler),
])

if **name** == "**main**":
    application.listen(8888)

print 'starting'

try:
    ioloop.start()
except KeyboardInterrupt:
    print '^C pressed'
finally:
    print 'done'

Run the server:
sudo python server.py

• Expected results
  The server starts and waiting for connection
• Actual results (with terminal output if applicable)

Traceback (most recent call last):
File "server.py", line 15, in
application.listen(8888)
File "/usr/local/lib/python2.7/dist-packages/tornado/web.py", line 1850, in listen
server.listen(port, address)
File "/usr/local/lib/python2.7/dist-packages/tornado/tcpserver.py", line 126, in listen
sockets = bind_sockets(port, address=address)
File "/usr/local/lib/python2.7/dist-packages/tornado/netutil.py", line 194, in bind_sockets
sock.bind(sockaddr)
File "/usr/lib/python2.7/socket.py", line 224, in meth
return getattr(self._sock,name)(*args)
socket.error: [Errno 98] Address already in use

(Note that socket 8888 is not used)

[sunilmut]

This is quite likely related to #996. If you take a strace strace -o <strace_file> -ff <cmd> and share out the <strace_file>, I am happy to take a look and confirm.

And, thanks for trying out WSL!

[harveypham]

strace attached. Thank you for taking time looking into this.

strace.71.txt

[zhwei820]

temperory solution:

change : tornado\netutil.py
line 111: def bind_sockets(port, address=None, family=socket.AF_UNSPEC,

to def bind_sockets(port, address=None, family=socket.AF_INET,

[benhillis]

I am no longer hitting this issue on 1803. Please reopen if you continue to have issues.