[support] CPU usage

[Daniel Carrera]

Hi all,

I have new information. At the time the school was blocked, this IP was 
taking up 500 HTTP connections and the server is configured to support 
1000. So this one IP was taking up half of the HTTP connections.

500 connections seems absurd, and so I'm convinced that there's 
something wrong at the school. The best hypothesis so far is the 
pre-scanning thing (thanks Jamie).

That said, I would like to better understand what "500 HTTP connections" 
means. If you get a single web page that has one HTML file, two images 
and two CSS files, is that one HTTP connection or five? In other words, 
does "500 HTTP connections" equate to 500 users or 100?

Also, I have no idea if 1000 HTTP connections is a reasonable 
configuration or not.

Thanks.
Daniel.


Jamie Holly wrote:
> I know Websense does pretty much the same thing as Blue Coat in "pre 
> scanning" sites. The best solution is to use css compression/aggregation 
> (in D5+) and javascript compression/aggregation (D6) to reduce requests. 
> Those are some of the files these services latch onto, and when they 
> read the entire site they won't cache the files, but rather reread them 
> on every page request.This will help keep the cpu usage down since 
> Apache won't have to keep spawning connections for the files.
> 
> Also any kind of caching you can get in there. There are some scenarios 
> and modules it won't work with. For example - if your Drupal install is 
> in a subfolder of the web root. One way to fix that is to put Drupal on 
> its own subdomain.  Also trying op-code level caching like APC is a big 
> plus (generally a 20%+ increase). Another option is using something like 
> cacherouter with memcache and then enabling the page caching through 
> that. With apc+cache router+memcache, I can pump out over 200 requests 
> per second on an old dual-core AMD server and my load never goes above 
> 60 using D6.