Questions regarding limits of processes launched by system, exec, passthru ...

[email protected] (Valentin Schmid - ICSurselva AG) Thu, 25 Sep 2008 10:39:03 +0200

Newsgroups	php.install
Message-ID	<[email protected]>

Hello all,

Is there a way to limit the memory consumption and / or the CPU
consumption of processes launched by the php functions system,
exec, passthru, proc_open and shell_exec?

We use mod_php with an apache (mpm-prefork) on Linux.

The following settings don't have any effect at all:
PHP:
   max_execution_time 30
   memory_limit 8M
Apache:
   RLimitCPU 30 30
   RLimitMEM 8388608 8388608

The limits above do have effect on php-scripts (without system calls)
and on CGIs (as well on processes launched by CGIs).

Any Ideas?

Kind Regards
valli


PS: I tested it with the following two scripts:
system_memorytest.php
=====================
<html>
<head>
   <title>php-systemcall-memory test</title>
</head>
<body>
   php-systemcall-memory test<br>
   ... and here's the system call:<br>
   <pre>
<?php
    $cmd = '/usr/bin/perl -e \'
       $| = 1;
       print "start of the systemcall<br>\n";
       $s = "teststr_";
       while (1) {
          print "len=".length($s)."<br>\n";
          sleep(1);
          $s .= $s;
       }
    \'';
    print htmlspecialchars($cmd);
?>
   </pre>
<?php
   ob_flush();
   flush();
   system($cmd);
?>
</body>
</html>


system_timeouttest.php
======================
<html>
<head>
   <title>php-systemcall-timeout test</title>
</head>
<body>
   php-systemcall-timeout test<br>
   ... and here's the system call:<br>
   <pre>
<?php
    $cmd = '/usr/bin/perl -e \'
       $| = 1;
       print "start of the systemcall<br>\n";
       $i = 0;
       while (1) {
          if (($i % 10000000) == 0) {
             print "i=".$i."<br>\n";
          }
          $i += 1;
       }
    \'';
    print htmlspecialchars($cmd);
?>
   </pre>
<?php
   ob_flush();
   flush();
   system($cmd);
?>
</body>
</html>