If the application you're working with requires that you close the socket, then
it seems like you should be creating, connecting, sending on, and closing a new
socket every ten seconds in response to your flow stats coming in.
It looks like you may be not creating and connecting a new socket after the
first run, and are trying to reuse a socket that you'd closed (made possible by
the fact that you're saving a reference to an old one as self.sock, which you
can never actually reuse since you close it).
I put the following code in an app (and then kick it off by calling it in my
Component's install()), and it seems to work just fine:
def handle_timer (self):
import socket
self.post_callback(5, self.handle_timer)
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect(("",5000))
sock.send("Hello world!\n")
sock.close()
Can you test if this seems to work for you? (I just run "nc -lk 5000" to give
it something to connect to.)
As a sidenote: These calls are blocking, and it's not nice to block the thread.
Using Twisted is the preferred solution. But since this is only periodic and
is connecting to localhost, etc., I am not sure that's worth worrying about.
As I said, it has been a long time since I have looked at NOX's threading
stuff, but nothing immediately comes to mind about why this wouldn't work.
-- Murphy
On Aug 15, 2011, at 2:15 PM, chris oleke wrote:
> Murphy, the thing is I'd pretty much want to maintain the sockets that I'm
> using at the moment since the third party application is tailored to work
> with them. When I send the data from NOX, I have to close the sockets because
> the data won't be received on the other end if the sockets remain open. My
> flow stats are generated every 10 seconds so my aim is to have them sent
> continously. I had previously tried using sock.setblocking(0) but encountered
> an error "operation already in progress" so abandoned using it.
>
> On Sat, Aug 13, 2011 at 2:34 AM, Murphy McCauley <jam...@nau.edu> wrote:
> It has been long enough since I've looked at the co-op threading in NOX that
> I don't immediately know what the problem you're having with the file
> descriptors going away is. You're sure you're not calling close() on them?
> You could try setting the socket to non-blocking mode with
> sock.setblocking(0).
>
> It might be possible to get asynccore to work, but I think it'd probably be
> some trouble. Twisted, on the other hand, should more or less just work. I
> think you can probably look at the NOX webservice stuff for a bit of an
> example, but it shouldn't be much different than any other Twisted code.
>
> Or if you would be okay with communicating with the other process via JSON
> strings, you could use jsonmessenger. Look in monitoring.py from the
> monitoring component for an example.
>
> Hope that helps.
>
> -- Murphy
>
> On Aug 12, 2011, at 2:03 PM, chris oleke wrote:
>
>> Hi
>>
>>
>>
>> Hopefully this is still within the Nox domain. I have a python application
>> that is using sockets to send out flows that I have obtained from a
>> flow_stats_in_event to an application external of Nox. This is how I’m doing
>> it
>>
>> self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
>> self.sock.connect(("",5000))
>> self.sock.send(repr(flows))
>> self.sock.close()
>>
>> Unfortunately I can only send the flows once before the sockets close after
>> which I get the errors below
>>
>> self.sock.send(repr(flows))
>> File "/usr/lib/python2.6/socket.py", line 167, in _dummy
>> raise error(EBADF, 'Bad file descriptor')
>> error: [Errno 9] Bad file descriptor
>>
>> It’s obviously as a result of trying to send information out on a socket
>> that’s been closed. I have tried to look at asyncore and see if I can have
>> an asynchronous socket but haven’t had any luck and my application’s seems
>> to lock/freeze the few times I have tried. Is there a way I can have the
>> socket remain connected so I can have flows sent constantly and also be able
>> to receive data when sent from the external application. I would like a
>> demonstration as well if it’s possible.
>>
>>
>>
>> Thanks
>>
>> Chris
>>
>> _______________________________________________
>> nox-dev mailing list
>> nox-dev@noxrepo.org
>> http://noxrepo.org/mailman/listinfo/nox-dev
>
>
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