How to keep process running after apache restart.

Applications Web Development
1

Hi, I have a PHP application that starts a couple of processes on the server...the problem is that if I restart apache those running apps will die.

How can I start them in a way that they are not killed when I restart/stop apache ?

      $cmdstr = "nohup ".$config['hsp_path']."/".$config['sc_trans']." ".$config['hsp_path']."/autodjs/".$port."/".$srvname.".conf";
      $cmdstr .= " > /dev/null & echo $!";
      $pid = shell_exec($cmdstr);

This is how I start that app.

2

You should do this:

service httpd reload

'reload' option does not close alive connections.

3

Thank you for your reply but that is not the solution I am looking for, still waiting for suggestions.

4

I'm guessing that the parent process is sending a term signal to each child process. The nohup command will not be effective in this case as it only ignores the hangup signal; it may also not be effective if the invoking shell is not associated with a tty, but that's neither here nor there.

What might help would be to wrap your command in a shell subcommand that causes interrupt, term, hup and quit signals to be ignored. I've no experience with PHP, but from your example it might look something like this:

 $cmdstr = "ksh -c '(  trap \"\" 1 2 3 4 15;  "
$cmdstr .= ".$config['hsp_path']."/".$config['sc_trans']." ".$config['hsp_path']."/autodjs/".$port."/".$srvname.".conf";
      $cmdstr .= " > /dev/null  )' &;  echo $!";
      $pid = shell_exec($cmdstr);

The idea behind this is that the PHP causes kshell (probably works in bash too) to be invoked to execute the command. The command given to the shell begins with a trap command that causes signals 1,2,3,4 and 15 to be ignored (the "") before executing the intended command.

I've assumed that the .= PHP operator is a += like operator and appends the string to the current value.

For a simple example, if my assumptions about PHP are wrong, consider the following that invokes the command t24 using this technique.

ksh -c '( trap "" 1 2 3 4 15; t24 )' &

I specifically invoke ksh as some systems invoke sh with a 'shell-exec' command and I don't know if plain Bourn shell supports this or not. If ksh is not in your path you will need to use the fully qualified pathname.

Hope this helps.

5

Thank you for the reply, I have implemented your method but when apache is restarted the process still dies,

  $cmdstr  = "ksh -c '(  trap \"\" 1 2 3 4 15;  ";
  $cmdstr .= $config['hsp_path']."/".$config['sc_trans']." ".$config['hsp_path']."/autodjs/".$port."/".$srvname.".conf";
  $cmdstr .= " > /dev/null  )' & echo $!"." ;";
  $pid = shell_exec($cmdstr);
6

One more slight tweek to try, then Im out of ideas:

$cmdstr  = "ksh -c '(  trap \"\" 1 2 3 4 15;  ";
  $cmdstr .= $config['hsp_path']."/".$config['sc_trans']." ".$config['hsp_path']."/autodjs/".$port."/".$srvname.".conf";
  $cmdstr .= " > /dev/null & )' & echo $!"." ;";
  $pid = shell_exec($cmdstr);

Adding an amper (&) before the closing paren should cause the process to become 'detached' from its process group and parent process (ppid should be 1) and unavailable to be signaled as a part of the process group (assuming that this is how/why the process is terminating as apache is bounced). The side effect of this is that the pid assigned to $pid will be incorrect; it will be that of the subcommand that invoked the process rather than the process itself.

Good luck.

7

Thank you for your efforts, it's getting killed , is there no way of keeping a process alive that was started from php ? The process dies on reload/stop/etc...