severity 450581 normal
thank you
It's normal bug in php. Certainly not critical. Linux systems has
several ways how to prevent processes eating all the available memory.
For the record:
Finally I found out what it was AND it was / is (using this script) a
major flaw in the (gz) output handler; a user on the server uses in his
code;
ob_start("ob_gzhandler", 9);
something();
ob_flush();
If something() generates a certain amounts of data, the ob_gzhandler
will get stuck in a loop, eating all memory.
In the user his particular case, because his database was not working,
some pages always have this 'magic size' (probably some factor of 9 in
this case).
I tried this on the latest stable of PHP 5 and the bug is still there;
you can crash any php hosting machine on the net with this :(
As to prevent this kind of thing from happening, I put the following
code on the machines;
#!/usr/bin/perl
$maxmem=10;
while(1) {
@r=`ps auxwhww|awk '{print \$4,\$2,\$11,\$12,\$13,\$15}'|grep
httpd-users|grep -v grep`;
foreach(@r) {
chomp;
/(.*?)\ (.*?)\ (.*)/;
if ($1>$maxmem) {
print "$_ killed\n";
`kill -9 $2`;
}
sleep 1;
}
Update: Only PHP5.x is affected, not lower (tested); didn't try higher.
I have code to reproduce it every run.
tluyben píše v Čt 08. 11. 2007 v 11:42 +0100:
> Package: libapache2-mod-php5
> Version: 5.x
> Severity: critical
> Justification: breaks the whole system
>
> More info;
>
> http://brainfish-eat-fishbrain.blogspot.com/2007/11/checking-what-is-eating-your-memory_08.html
>
> -- System Information:
> Debian Release: 4.0
> APT prefers stable
> APT policy: (500, 'stable')
> Architecture: i386 (i686)
> Shell: /bin/sh linked to /bin/bash
> Kernel: Linux 2.6.18-3-686-bigmem
> Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
>
>
>
> _______________________________________________
> pkg-php-maint mailing list
> [EMAIL PROTECTED]
> http://lists.alioth.debian.org/mailman/listinfo/pkg-php-maint
--
Ondřej Surý <[EMAIL PROTECTED]> *** http://blog.rfc1925.org/
Kulturní občasník *** http://www.obcasnik.cz/
Nehoupat, prosím *** http://nehoupat.blogspot.com/
