Possibly a supervisor process should monitor your primary process to see if it's still making progress. You might touch somefile from within the memorymonster, and have the supervisor check that file not becoming too old.

I've found

if (my $chld = fork) {
   # supervise $chld from here 
} 
else { 
   # unreliable process here
}
[download]

useful. hth

Edit: Maybe you can make do with just confirming a successful run with a print "successfully done\n";