platform is Linux Red Hat. I am currently testing with 9 servers in the list. When I run the script without Parallel::Forkmanager what is happening is that the script will loop thru and process each server using the system call to scp a file. The script will wait for that system call to finish and then continue to the next server. It seems like that is exactly whats happening with the fork. It's processing 1 server at a time, unless I'm not seeing this correctly. The reason I had the wait for all children is that I want to make sure all the servers have been processed before continuing on. I am adding time stamps to the print statements to show what is happening. Here is the code and the output. 



my $concurrent_fork_limit = 9;
my $fork_manager = Parallel::ForkManager->new($concurrent_fork_limit);

foreach my $server (@servers) {

  my $pid = $fork_manager->start;

  if ($pid) {
    my ($dstamp, $hstamp) = &next_time();
    print "$dstamp $hstamp $$: child process started, with a key of $s
+erver ($pid)\n";
    print "\nWorking On Server ->  $server\n";
    print "Sending File      ->  $file\n";

    my $timeout = 20;
    eval {
       local $SIG{ALRM} = sub { die "alarm\n" };
       alarm $timeout;
       my $rc = system("scp -p $file $user\@$fqdn:$rpath/$fname");
       print "\nReturn Code For Server -> $server  File -> $file  = $r
+c\n\n\n";
       alarm 0;
    };
    if( $@ ) {
      $nogood{$server}++;
    }
  }
  $fork_manager->finish;
}

$fork_manager->wait_all_children();
my ($fstamp, $dstamp, $hstamp) = &next_time();
print "\n\n\n$dstamp $hstamp All Children Finished, Continuing\n\n";

[download]


04/06/2017 08:56:23 127266: child process started, with a key of server01 (127269)
Working On Server -> server01.domain.com
Sending File -> mkdir.pl
Return Code For Server -> server01.domain.com File -> mkdir.pl = 0


04/06/2017 08:56:25 127266: child process started, with a key of server02 (127273)
Working On Server -> server02.domain.com
Sending File -> mkdir.pl
Return Code For Server -> server02.domain.com File -> mkdir.pl = 0


04/06/2017 08:56:26 127266: child process started, with a key of server03 (127278)
Working On Server -> server03.domain.com
Sending File -> mkdir.pl
Return Code For Server -> server03.domain.com File -> mkdir.pl = 0


04/06/2017 08:56:28 127266: child process started, with a key of server04 (127282)
Working On Server -> server04.domain.com
Sending File -> mkdir.pl
Return Code For Server -> server04.domain.com File -> mkdir.pl = 0


04/06/2017 08:56:29 127266: child process started, with a key of server05 (127286)
Working On Server -> server05.domain.com
Sending File -> mkdir.pl
Return Code For Server -> server05.domain.com File -> mkdir.pl = 0


04/06/2017 08:56:31 127266: child process started, with a key of server06 (127290)
Working On Server -> server06.domain.com
Sending File -> mkdir.pl
Return Code For Server -> server06.domain.com File -> mkdir.pl = 0


04/06/2017 08:56:32 127266: child process started, with a key of server07 (127294)
Working On Server -> server07.domain.com
Sending File -> mkdir.pl
Return Code For Server -> server07.domain.com File -> mkdir.pl = 0


04/06/2017 08:56:34 127266: child process started, with a key of server08 (127298)
Working On Server -> server08.domain.com
Sending File -> mkdir.pl
Return Code For Server -> server08.domain.com File -> mkdir.pl = 0


04/06/2017 08:56:35 127266: child process started, with a key of server09 (127303)
Working On Server -> server09.domain.com
Sending File -> mkdir.pl
Return Code For Server -> server09.domain.com File -> mkdir.pl = 0


04/06/2017 08:56:35 All Children Finished, Continuing

In reply to Re^2: Parallel::Forkmanager question by jamesgerard1964
in thread Parallel::Forkmanager question by jamesgerard1964

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