PuTTY Network Timeout Error

Question

I'm using PuTTY on my Windows machine to use SSH on my university server. I run analyses that take up to 3 days to complete. I can connect and start the analyses but eventually get an error message 'PuTTY Network Error: Software caused connection abort'. I have problem solved this - the issue lies with the period of inactivity on PuTTY where it is running the analyses. The network connections ect are all fine. At the moment the only way I can get the analyses to complete is to press enter every couple of hours. This really is annoying as I have to get up during the night!

I'm not a computer whizz whatsoever and would really apprentice if anyone could suggest a solution.

Thanks :)

Answer 1

Either of the following methods (I prefer the second but YMMV)

1. Prevent timeout
   • Fiddle with Putty's settings such as Enable TCP Keepalives and seconds between keepalives.
   • Tell the shell not to get bored (unset TMOUT)
2. Change what you are doing so you don't hold a session open while inactive for several days
   • output redirection (>)
   • disconnecting STDIN from tty (&)
   • prevent disconnection signalling the process (nohup)

e.g.

nohup ./my_analysis > analysis.out 2> analysis.err &; exit;

You can check progress by e.g. logging in again and using

tail -f analysis.out

More complicated needs can often be accomodated using named pipes.

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Other references

• how to make putty ssh connection never to timeout when user is idle?
• How to make putty to not break my session after some time?
• PuTTY and how to keep alive telnet session

Answer 2

You could also use screen if it's available.

It would allow you do run whatever command within a screen session (which wouldn't timeout) and you'd be able to reconnect it later. A basic use could look like the following:

1. Run screen
2. Start analysis
3. Detach (Ctrl+A D) the screen (or wait for the timeout)
4. Reconnect later using screen -r