Why the info 'A worker can handle no more than 1024 simultaneous connections' has been removed from http://nginx.org/en/docs/windows.html ?

[Maxim Dounin]

Hello!

On Wed, Nov 16, 2022 at 03:31:14PM +0000, Masseau Olivier via nginx wrote:

> Previous we could find this very important information on the 
> "nginx for Windows" page ( http://nginx.org/en/docs/windows.html 
> ) :
> 
> Known issues
> ...
> A worker can handle no more than 1024 simultaneous connections.
> ...
> 
> Why has it been removed ?
> I struggled a lot understanding why increasing 
> worker_connections above 1024 was not working on Windows.

As you can see from the source code repository of the nginx.org 
site, the relevant item was removed along with the documentation 
of the poll event method being supported on Windows (introduced in 
nginx 1.15.9):

http://hg.nginx.org/nginx.org/rev/4795c2ae5066
Added the "poll" method for Windows.

With the poll event method, as long as it is supported by the 
Windows version you are using (Windows Vista or later), nginx will 
use the WSAPoll() function, which, in contrast to select(), does 
not impose a hard-coded limit on the number of connections.  
You'll have to use the "use poll;" in your configuration to 
instruct nginx to use the poll event method, see 
http://nginx.org/r/use for details.

Note though that with poll there might be other issues, such as 
failure to report connect() errors till the timeout expires (see 
https://daniel.haxx.se/blog/2012/10/10/wsapoll-is-broken/ for 
details; shouldn't be a major issue in case of nginx though, since 
errors while connecting to backend servers aren't expected to 
happen).

Also note that Windows isn't really designed as an efficient 
server platform, and nginx is not really designed to work on 
Windows.  Running nginx on Windows in production setups might not 
be a good idea.

Hope this helps.

-- 
Maxim Dounin
http://mdounin.ru/