1 output_buffers

because static file used sendfile in nginx, and if you need modify file
content, you need read file content to memory(example gzip filter), this
memory size is output_buffers.

first arg is buf number, second is buf size. if allocated memory greater
than number*size, nginx will send buf and then continue read;

2 aio

yes.

3 sendfile

first, sendfile have limit(2g - 1) in nginx, if file size is greater than
limit, nginx will send partially everytime. second, because fd is NONBLOCK,
so server is not block.

On Tue, Sep 27, 2011 at 7:36 PM, Hagai Avrahami <hagaia@qwilt.com> wrote:

> Hi
>
> I am intend to use NGINX (LINUX) for serving static files with high
> concurrency and bandwidth.
> Some of the files is served from the disk and some from cache.
> I am trying to find the configuration for best performance.
>
> I have some questions regarding NGINX configuration.
>
> 1. *output_buffers 1 32k*
> ----------------------------------------
> This directive excepts 2 inputs
> can someone explain me the meaning of each input
> I can see that 32K is size of data (per fetch) when reading from a DIsk -
> what else it influences?
> When serving big files, best Disk utilization is in blocks of 1MB, is it OK
> to change this directive to 1024k?
>
> 2. *aio*
> ----------------------------------------
> **I read in Wiki the following
> *" This directive is usable as of Linux kernel 2.6.22. For Linux it is
> required to use directio, this automatically disables sendfile support."*
> when using AIO I must use *directio on*? (when testing I could see the
> file is served from the cache - which means it is not using O_DIRECT)
>
>
> 3. *sendfile
> *----------------------------------------
> Is NGINX try to send a file using 1 sendfile call (count = file size)?
> If so when trying to send file residing only on the Disk, the server is
> blocked till end of transmition?
> In this model serving multiple files some on the disk and some cached is
> inefficient?
>
> Will be happy to get any answer or opinion
>
> Thanks
> Hagai
>
>
>
>
>
> --
>
> *Hagai Avrahami*
> Qwilt | Work: +972-72-2221644| Mobile: +972-54-4895656 | hagaia@qwilt.com<yoav@qwilt.com>
>
>
> _______________________________________________
> nginx mailing list
> nginx@nginx.org
> http://mailman.nginx.org/mailman/listinfo/nginx
>



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