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From: Josip Almasi <joe@vrspace.org>
Newsgroups: comp.lang.java.programmer
Subject: Re: java unix domain sockets ... or substitute
Date: Fri, 05 Sep 2014 10:20:58 +0200
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On 09/04/2014 11:14 AM, Andreas Leitgeb wrote:
> Josip Almasi <joe@vrspace.org> wrote:
>> IMHO domain sockets are not in java for good reason - they add little
>> value over pipes when used locally, but add complexity, as it's easier
>> to work with files/pipes than sockets.
>
> Exactly that added complexity is what I now have to mimic with pipes and
> where it ends up even more complicated than what I'd think domain sockets
> would have been.
> As a bonus, I'd be able to detect stale sockets, in case the server crashed,
> but I cannot reliably detect a stale named pipe. Accessing it will merely
> block until someone else restarts the server.

I think you can detect stale pipes, with fuser and/or lsof - they will 
not be opened by any processes.
Something like
for FILE in `find /tmp -type p`
do
   PROCCNT=`fuser $FILE | wc -w`
   if (( $PROCCNT == 1 ))
     fuser -k $FILE
   elif (( $PROCCNT == 0 ))
   then
     rm -f $FILE
   fi
done
every (couple of) minute(s).

>> With domain sockets you'd also get filesystem nodes, just not two for
>> each client, with less bookkeeping of stale nodes.
>> Then again, you also can create pipes in /tmp, and leave cleanup to system.
>
> The mean-time between reboots is rather long (think of years), so I couldn't
> just idly fill /tmp. The rate of client-connects is expected to be high
> enough that this would cause problems.

Cleaning /tmp is usually night-time cron job.
Think you only need one or two cron jobs to keep your pipes under control.
I haven't seen AIX, Solaris nor ksh in years though.

Regards...