Our web server has been migrated to a new machine. While Apache 1.3 on the old box had little or no trouble dealing with a series of rewriterules, Apache 2.0 on the new box generates huge loads performing the same task.

Removing the rewriterules brings our load back to acceptable levels.

Expected result:

An URL of the format [myserver.com...]

returns the image /cam_5.jpg or /notallowed.jpg - depending on the requesting IP address and time of the request.

Failing approach:

Our httpd.conf looks like this:

 RewriteLock /usr/local/etc/apache2/rewrite.lock
<VirtualHost aaa.bbb.ccc.ddd:80>
 RewriteEngine On
 RewriteMap parse-token prg:/usr/local/etc/apache2/parsetoken.pl
 RewriteRule ^/([A-F0-9]{24})+/(cam_+[1-6]+\.jpg)$ /$2/$1%{REMOTE_HOST}
 RewriteCond ${parse-token:$2} <240
 RewriteRule ^/(cam_+[1-6]+\.jpg)+/(.*)$ /$1 [L,S=1]
 RewriteRule ^/(.*)+\.jpg http://my_other_server.com/notallowed.jpg [L,R]
 RewriteRule ^/([A-F0-9]{24})+/(cam_+[1-6]+\.jpg)$ /$2
</VirtualHost>

And the script is:

#!/usr/bin/perl
#
# Apache mod_rewrite script
# Parse time / ip token - determine whether
# to grant access to webcam images
$¦ = 1; # Turn off buffering
while (<STDIN>) {
 $tokenIp='';
 $tokenTime = substr($_,0,8);
 for ($n=8;$n<=20;$n+=4){
 $temp = hex(substr($_,$n,2));
 $tokenIp .= sprintf('%d', $temp) . '.';
 }
 $tokenIp = substr($tokenIp,0,-1);
 $reqIp = substr($_,24,-1);
 $index = rindex($tokenIp,'.') -1;
 $tokenIp = substr($tokenIp,0,$index);
 $reqIp = substr($reqIp,0,$index);
 $myTime = time();
 $tokenTime = hex($tokenTime);
 $tokenTime = sprintf('%d', $tokenTime);
 $timeDiff = int(abs($myTime - $tokenTime) / 60); # no seconds needed
 if ($timeDiff > 999) {
 $timeDiff = 999;
 }
 $outString = $timeDiff;
 while (length $outString <3){
 $outString = '0' . $outString;
 }
 if ($tokenIp ne $reqIp){
 $outString = '999';
 }
 print $outString;
 print "\n"
}

My perl-fu is way rusty, optimizations are greatly appreciated, but the old box handled everything "just fine"...

Now I see the following within mere seconds:

me@host ~ : w
5:54PM up 18 days, 23:35, 3 users, load averages: 0.36, 0.27, 0.25

me@host ~ : w
5:54PM up 18 days, 23:35, 3 users, load averages: 1.05, 0.41, 0.31

me@host ~ : w
5:55PM up 18 days, 23:36, 3 users, load averages: 2.78, 0.97, 0.51

Can anyone nudge me in the right direction?

Norbert