Re: web server optimization question

[Aleksandar L. <al-...@no...>]

Hi,

On Fre 07.09.2007 03:12, jari pietila wrote:
>Robert,
>
>I  did some experimenting and can share the results so far:

Nice to share your experience ;-), thanks.

>- with ligthttpd and minimal server tuning, I got around 3300 CAPS with
>   1000 virtual clients.
>    (load-curl  0.41 re-compiled with optimization) compared to 1200
>    with Apache.
>   
>      Then the good news:
>      My client in this test was is dual-core P4 2.8Ghz, 1GB RAM, Fedora 5 
>     and with -t 2 option there was almost linear scaling leading about 6000 CAPS!
>      Very impressive,  thanks  for  pointing  this  out.
>    
>     - I then switched to nginx, and  was able to reach  8000 CAPS
>       with -t 2 and 1000 virtual clients.
>       (no change in client configuration )

Cool ;-)

>  But there is also a change in server behavior, lighttpd does NOT use
>  persistent connections and closes each TCP connection (TCP FIN server
>  ->client ).
>   This is actually the kind of behavior, I wanted to see:
>    NO persistence, thus  creating load on DUT that needs to track TCP
>    session creation and closing.

I'am not a fan of lighty but to be fair have you looked into:

http://trac.lighttpd.net/trac/wiki/Docs%3APerformance

>   Nginx  with default settings has persistence,
>    (and not sure if there is directive to make it not to do so),
>    so this seems to explain the higher CAPS number.

Afaik there is no option to switch off the keep-alive but you can tune
it:

http://wiki.codemongers.com/NginxHttpCoreModule#keepalive_timeout

>   I also experimented a little with the number of virtual clients, 
>   but I got about the same results with 256 clients,
>    and performance started to degrade around 1500 clients.
>    
>       - Finally, I tried configuration  where client closing the connection, but with this 
>     I got  much lower CAPS with both lighttpd and nginx.

Have you tried to turn on/off tcp_{nodelay,nopush), yust for info?!

http://wiki.codemongers.com/NginxHttpCoreModule#tcp_nodelay

BR

Aleks