Hi,

I am having a problem with ending child processes. I am actually trying to a script on different workstations parallely. The way I am trying to do this is to launch a bunch of child processes that will rsh to each workstation and run the local script. With this approach I seem to be running out of open sockets, because I ended up launching too many child processes at a time. So i tried using the waitpid the command which will wait for 20 processes to end and then launch another batch of 20 once these are done. But for som reason I am not able to control these and keep running out of open sockets. Maybe you monks can take a look at it and suggest what I am doing wrong here. 

foreach $host (@hosts) {
 chomp ($host);
 
     my $templocal = "tmpclean.local.prl";
     my $cmd_rsh ="/bin/rshto -to 60";
             
     $pid = fork;
     if ($pid == 0) {
    # child
                
        print "$cmd_rsh $host $templocal 2 \n";
    open(PIPEHANDLE, "$cmd_rsh $host $templocal 2 |");
    my @output = <PIPEHANDLE>;
    close PIPEHANDLE;

    open(OUTFILE, ">> $output_file");
    print OUTFILE @output;
    close OUTFILE;
    
        exit 1;
   } else {
    push(@pids,$pid);
   }
            
   if ($#pids > 10) {
    print "more than 10 processes running \n";
        my $id = waitpid(-1,0);
    while (!(WIFEXITED($?)) ) {} 
    $#pids = -1;
    #sleep 5; 
   }
            
}

[download]


am I doing the right thing here ?? All i want to do is launch around 20-50 processes without running out of open sockets. Please Help.

Waris

In reply to How do you wait for a process to end ? by jalebie

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.