[Twisted-Python] Re: How to detect dead client connections in twisted

[Alvin Delagon]

Problem solved! I digged through the twisted.internet source codes and found
this facility:

 def setTcpKeepAlive(self, enabled):
        self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_KEEPALIVE,
enabled)

I modifying the simple twisted server:

#!/usr/bin/python
from twisted.internet import protocol
from twisted.internet import reactor

class EchoProtocol(protocol.Protocol):
    def __init__(self):
        pass

    def connectionMade(self):
        print "Client Connected Detected!"
        ### enable keepalive
        self.transport.setTcpKeepAlive(1)

    def connectionLost(self, reason):
        print "Client Connection Lost!"

    def dataReceived(self, data):
        self.transport.write(data)


factory = protocol.Factory()
factory.protocol = EchoProtocol
reactor.listenTCP(8000, factory)
reactor.run()

Now the server is aware of keepalive timeouts now. Might as well use it in
my xmpp server. :)


---
Alvin Delagon


On Tue, Jun 3, 2008 at 3:21 PM, Alvin Delagon <adelagon at gmail.com> wrote:

> Yes it supposed to be handled by the tcp_keepalive itself (as I assumed).
> The weird thing was that we had this configuration:
>
> Ubuntu Linux Server 2.6.15-26
> tcp_keepalive_time 7200
> tcp_keepalive_probes 9
> tcp_keepalive_intvl 75
>
> I have an XMPP client last sent a packet to the server at May 29 15:57:25
> telling that it will enter an idle state. On May 30 approx 08:00:00 I shut
> down my PC which hosts my XMPP client thus causing a half-opened state. The
> next day (17:41:11) while checking the logs, its still in half-opened state
> and my server still thinks that I'm online. It seems that tcp_keepalive
> kernel feature that's supposed to run every 2 hours didn't kick in.
>
> ---
> Alvin Delagon
>
>
> On Tue, Jun 3, 2008 at 2:42 PM, Gabriel Rossetti <mailing_lists at evotex.ch>
> wrote:
>
>>
>> Alvin Delagon wrote:
>>
>>>
>>> I just recently discovered that it's a TCP half-open socket scenario that
>>> can be remedied by monitoring client heartbeats. This is not twisted related
>>> issue. Thanks anyway. :)
>>>
>>> Alvin Delagon
>>>
>>>
>> Just a question, could setting the tcp keepalive feature on the server
>> side (not sure if that is possible), would that make the server detect that
>> the connection is dead/half-open?
>>
>> Gabriel
>>
>> _______________________________________________
>> Twisted-Python mailing list
>> Twisted-Python at twistedmatrix.com
>> http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python
>>
>
>
>
> --
> http://www.alvinatorsplayground.blogspot.com/
>



-- 
http://www.alvinatorsplayground.blogspot.com/
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