On Thu, 25 Sep 2008, Valentin Schmid - ICSurselva AG wrote:
To: php-install@xxxxxxxxxxxxx
From: Valentin Schmid - ICSurselva AG <php@xxxxxxxxxxxxxxxxxx>
Subject: Questions regarding limits of processes launched by
system, exec, passthru ...
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>
What OS are you running? If it's Unix/Linux then you might
be able to control these settings with ulimit.
Please see the manual page for ulimit for details.
'pinfo' is a lynx-style info page browser that I find
very usefull for browsing info manual pages on Linux.
from the Linux info pages for ulimit:
Here is a list of resources for which you can specify a
limit. Memory and file sizes are measured in bytes.
`RLIMIT_CPU'
The maximum amount of CPU time the process can use. If it
runs for longer than this, it gets a signal: `SIGXCPU'.
The value is measured in seconds. *Note Operation Error
Signals::.
`RLIMIT_FSIZE'
The maximum size of file the process can create. Trying to
write a larger file causes a signal: `SIGXFSZ'. *Note
Operation Error Signals::.
`RLIMIT_DATA'
The maximum size of data memory for the process. If the
process tries to allocate data memory beyond this amount,
the allocation function fails.
`RLIMIT_STACK'
The maximum stack size for the process. If the process
tries to extend its stack past this size, it gets a
`SIGSEGV' signal. *Note Program Error Signals::.
`RLIMIT_CORE'
The maximum size core file that this process can create.
If the process terminates and would dump a core file larger
than this, then no core file is created. So setting this
limit to zero prevents core files from ever being created.
`RLIMIT_RSS'
The maximum amount of physical memory that this process
should get. This parameter is a guide for the system's
scheduler and memory allocator; the system may give the
process more memory when there is a surplus.
`RLIMIT_MEMLOCK'
The maximum amount of memory that can be locked into
physical memory (so it will never be paged out).
`RLIMIT_NPROC'
The maximum number of processes that can be created with the
same user ID. If you have reached the limit for your user
ID, `fork' will fail with `EAGAIN'. *Note Creating a
Process::.
`RLIMIT_NOFILE'
`RLIMIT_OFILE'
The maximum number of files that the process can open. If
it tries to open more files than this, its open attempt
fails with `errno' `EMFILE'. *Note Error Codes::. Not all
systems support this limit; GNU does, and 4.4 BSD does.
`RLIMIT_AS'
The maximum size of total memory that this process should
get. If the process tries to allocate more memory beyond
this amount with, for example, `brk', `malloc', `mmap' or
`sbrk', the allocation function fails.
`RLIM_NLIMITS'
The number of different resource limits. Any valid RESOURCE
operand must be less than `RLIM_NLIMITS'.
-- Constant: int RLIM_INFINITY
This constant stands for a value of "infinity" when
supplied as the limit value in `setrlimit'.
`ulimit' and the command symbols are declared in `ulimit.h'.
HTH
Kind Regards,
Keith Roberts
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