Forum OpenACS Development: AOLserver 4.1 for WU-Wien

Posted by Andrew Piskorski on
Indeed, that is quite impressive!

Gustaf, your slides mention that your using AOLserver 4.1. 4.1 is still in alpha, so I'm curious why you're using it rather than 4.0.x - could you tell us more about that? You said your rate limitor is serving dynamic content in AOLserver, so is it because of performance improvements there in 4.1?

Posted by Gustaf Neumann on
We simply got 4.1 (from cvs?) and it happens to work nicely.
I have no idea whether there is a performance difference
compared to the 4.0.* versions.  Here is the version we are using:

from ns.h:
*      $Header: /cvsroot/aolserver/aolserver/include/ns.h,v 1.58 2004/03/10 04:45:04 dossy Exp $
#define NS_PATCH_LEVEL          "4.1.0"

The throttle module can throttle all kinds of requests. We
did not want to catch cases, where a user requests
an HTML page including a couple of images, but cases,
where multiple HTML pages are requested frequently within
a time period form a user. In "throttle check", we do simply
  if {[string match image/* [ns_guesstype $url]]} {
    return 0
On our site, practically all HTML page requests
are quite costly dynamic requests. Without the
throttling code, we had users who tried to copy
the whole site content with IE or other tools.
Our uses did that in particular, when the server was
quite busy. This eager copying however had an effect
of a DOS attack bringing the server to its knees.
The blocking code simply returns a short error
message to the requestor telling him to slow down...

Does this answer your question?