response times and network io

[Joe Williams]

I used httperf to give me the network I/O (KB/s) and response times. I 
could probably produce the sar data from each if you would like it. I 
assume the response times are due to Nginx not needing to take time to 
start up another process/thread?

Thanks.
-Joe




Igor Sysoev wrote:
> 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 joetify.com
>>
>>
>>     
>
>   

-- 
Name: Joseph A. Williams
Email: joe at joetify.com