response times and network io

Igor Sysoev is at
Fri Feb 29 19:38:36 MSK 2008

On Thu, Feb 28, 2008 at 08:24:24PM -0600, Joe Williams wrote:

> please excuse my typo. regarding network I/O nginx uses consistently 
> lower I/O than apache.
> regardless i am curious about how it processes requests differently to 
> obtain lower response times and network I/O.

How do you measure network I/O ?

In short, Apache and nginx use different model for processing requests.
Apache processes connection in one process or thread while nginx processes
thousand connections in one process/thread using scaleable methods such
as kqueue/epoll/etc.

> thanks for any help you can provide.
> -Joe
> Joe Williams wrote:
> >i am performing some httperf tests against apache and nginx. something 
> >i noticed that piqued my interest were the consistency of response 
> >times (0.4 ms each run regardless of number of request, much lower 
> >than apache in all cases) and network I/O (consistently higher than 
> >apache regardless of number of request). it also uses less cpu than 
> >apache and doesn't nearly drive up the load.
> >
> >are these normal results? is there a mechanism in nginx that keeps the 
> >response times low and consistent? also, is it normal that it uses 
> >more network I/O? if so, what is the cause? to me it would seem like 
> >that it uses more bandwidth to respond to the same number of requests 
> >which seems inefficient.
> >
> >please correct me if i am wrong. i am just trying to understand the 
> >core differences in how nginx works in comparison to apache and why i 
> >would see these performance differences.
> >
> >thanks for the help.
> >
> >-joe
> >
> -- 
> Name: Joseph A. Williams
> Email: joe at

Igor Sysoev

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