[VPM] monitor process, april meeting

[nkuipers]

Hello all,

I have a script that connects to a remote database, extracts one DNA sequence, 
runs it through a BLAST program on a different remote machine, and then 
updates the database with the new information.  Rinse and repeat, for every 
sequence.  I want this to be automated, such that if something goes horribly 
askew, my script can detect this and attempt to pick up where it left off, 
until it succeeds in doing so.  For example, let's say the BLAST server goes 
down and my BLAST system call hangs.  In this case, I want to pound the server 
with a "let me in?", say once every five minutes, until it connects, and then 
restart from the last successful sequence, which is stored in a tempfile.  I 
also want an interruption to be printed to a log file, and I think that both 
of these tasks could include altering the SIG handlers, though I am not sure 
if this is the best way, or what SIG handlers would need attention.  I suppose 
a crontab is an option, but I would like to keep everything as contained in my 
script as possible, rather than having little files flying around here and 
there, to make it more portable.  But if cron is the best way, so be it.  So, 
can anyone enlighten me as to what is involved in having a script "listen" to 
a process, and facilitate its continuity in the event of interruptions?

Oh, and I was thinking that for the April meeting, in the absence of any 
special topic, we could make this a journal club sort of event, where a couple 
of people select a favourite article from The Perl Journal or something, and 
present it.  Comments?

Thanks,

Nathanael