in reply to Problem Keeping Socket Alive

One problem is that the timeout method "sets the timeout interval that's used when performing I/O or connecting to a port. When a method doesn't complete within the timeout interval then it's an error and the error mode action is performed." If the remote process isn't going to output something for 7 days then you should disconnect from the socket, sleep(604800) and then reconnect. In other words, lower your timeout value and look elsewhere for the problem.

Another problem is that you assume that the process runs all the time and that there will never be a loss of connectivity. How about checking that the connection still exists before (or when) trying to read from the socket?

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Re: Re: Problem Keeping Socket Alive
by skamerman (Initiate) on Dec 23, 2002 at 17:05 UTC
    This program is logging phone calls in real time over ethernet, so I could be waiting from 1 sec to 5 hours for more output on the socket, depending on whether anybody calls or not. I will lower the timeout, though. Maybe I'll try 7200sec (2 hours)

    I explained the problem poorly - the script doesn't actually "die" - it's still running, just not logging the output anymore, and if I try to telnet to my device at the port that my script is supposed to be listening to, I am refused - so I know the socket is still open.
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      What does netstat show the state of the conn being when this error state happens? Also do you have control of the sending side of this? if so, it might make sense to do a heartbeat (a dummy packet that gets discarded in the scope of the log) every few minutes that forces all firewalls etc between the two hosts to think that the connection is active over long periods of inactivity.

      Edited:
      Also, getline is fine. And since you don't need this to timeout at all, you can use undef for the timeout value to turn off timeouts completely.

      -Waswas
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        Unfortunatly, I do not have control over the remote device. The socket is connected to a remote device server called a UDS-10 by Lantronix, this device is like an Ethernet to Serial brige, buffering output from a connected serial device (in this case a phone switch) and allowing me to collect the output over TCP/IP from port 10001 - but if I send it any data, it will disable logging on the phone switch, and I will have to turn it on again in their software. The phone switch itself is supposed to be connected to a serial printer, but I just connect it to this device, parse the data, and drop it into an Informix database.

        Do you think maybe the problem is in the $line = $socket->getline; statement? Should I be using $line = <$socket>; instead?
[reply]

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