[PATCH 4 of 4] Changed default value of sendfile_max_chunk to 2m

[Sergey Kandaurov]

> On 11 Oct 2021, at 21:58, Maxim Dounin <mdounin at mdounin.ru> wrote:
> 
> # HG changeset patch
> # User Maxim Dounin <mdounin at mdounin.ru>
> # Date 1633978667 -10800
> #      Mon Oct 11 21:57:47 2021 +0300
> # Node ID a6426f166fa41d23040e5b3aefb2d6340c10a53c
> # Parent  c7ef6ce9455b01ee1fdcfd7288c4ac5b3ef0de41
> Changed default value of sendfile_max_chunk to 2m.
> 
> The "sendfile_max_chunk" directive is important to prevent worker
> monopolization by fast connections.  The 2m value implies maximum 200ms
> delay with 100 Mbps links, 20ms delay with 1 Gbps links, and 2ms on
> 10 Gbps links.  It is also seems to be a good value for disks.
> 
> diff --git a/src/http/ngx_http_core_module.c b/src/http/ngx_http_core_module.c
> --- a/src/http/ngx_http_core_module.c
> +++ b/src/http/ngx_http_core_module.c
> @@ -3720,7 +3720,7 @@ ngx_http_core_merge_loc_conf(ngx_conf_t 
>     ngx_conf_merge_value(conf->internal, prev->internal, 0);
>     ngx_conf_merge_value(conf->sendfile, prev->sendfile, 0);
>     ngx_conf_merge_size_value(conf->sendfile_max_chunk,
> -                              prev->sendfile_max_chunk, 0);
> +                              prev->sendfile_max_chunk, 2 * 1024 * 1024);
>     ngx_conf_merge_size_value(conf->subrequest_output_buffer_size,
>                               prev->subrequest_output_buffer_size,
>                               (size_t) ngx_pagesize);
> 

Looks good.

-- 
Sergey Kandaurov