upstream keepalive connections for all servers or each server?

[Maxim Dounin]

Hello!

On Mon, May 08, 2017 at 04:24:59AM -0400, fengx wrote:

> As known, the keepalive directive can activate the connections cache for
> upstream servers. I know the connection pool is in each worker process. But
> I'ms confused that the connection number is for each upstream server or is
> shared for all servers? It's documented at
> http://nginx.org/en/docs/http/ngx_http_upstream_module.html#keepalive 

It is the number of keepalive connections to be cached for the 
whole upstream{} block, that is, all servers.

-- 
Maxim Dounin
http://nginx.org/