Nginx to apache reverse proxy, instruct use of unix sockets

Question

My Nginx reverse proxy works on the same machine as the webserver(apache) as follows

server {  server_name site.net;
    location / {
        proxy_pass http://localhost:82;
        proxy_set_header   Host             $host;
        proxy_set_header   X-Real-IP        $remote_addr;

    }
}

Now instead of using TCP connections to the backend apache, how can I tune it to use unix sockets?

Edit:
Can someone help with the full flow, instructing apache to listen on unix sockets too

AFAIK Apache doesn't support listening on a socket ... its a web server. If performance is your reason for doing this, the difference between sockets/tcp is negligible for most web servers - as the bottleneck is whatever app is running anyway (PHP/Perl etc.) — Ben Lessani, Oct 02 '12 at 21:04
I assume you have too many connections which stack up so you want to move proxy from tcp stack to socket. I would suggest you to try disable keepalive; also it might help to enable TCP_TW_REUSE (net.ipv4.tcp_tw_reuse) — Hrvoje Špoljar, Oct 08 '12 at 11:16

score 11 · Answer 1 · answered Oct 02 '12 at 21:56

11

While you most likely could set Nginx to proxy redirect to a socket using unix:/path/to/socket syntax, Apache Listen directive only accepts IPv4 or IPv6, so as far as I know you can't get Apache to listen on an unix socket.

answered Oct 02 '12 at 21:56

c2h5oh

1,489
10
13

It would be trivial to script a proxy to map the unix socket to a network socket - but you lose any performance benefit. OTOH the lo interface doesn't have nearly the same performance constraints as a physical interface, even if it does slow start, as long as you've got big congestion windows then it should run at nearly the same speed as a unix socket. – symcbean Oct 05 '12 at 11:49
Socket will still have edge on small requests where latency is essential. – c2h5oh Oct 08 '12 at 16:38
1

The why route them via a proxy? – symcbean Oct 22 '12 at 10:05

score 6 · Answer 2 · answered Sep 28 '12 at 18:38

6

You need to define an upstream like this:

upstream upstream_name {
        server unix:/path/to/socket fail_timeout=0;
}

And then set proxy_pass to reference that upstream by name, i.e.,

proxy_pass http://upstream_name

answered Sep 28 '12 at 18:38

Clint Miller

1,141
1
11
19

What about the webserver? Apache in this case. – Quintin Par Sep 28 '12 at 19:10
Possible to give an answer with a full flow? – Quintin Par Sep 28 '12 at 19:10
1

In a brief search, I couldn't find anything in the documentation that indicated that Apache is capable of listening on a unix domain socket. – Clint Miller Sep 28 '12 at 19:58
5

There is no need to define upstream to proxy requests to a unix socket, `proxy_pass http://unix:/path/to/socket:;` would do the trick as well, see http://nginx.org/r/proxy_pass. – Maxim Dounin Oct 03 '12 at 15:50

Nginx to apache reverse proxy, instruct use of unix sockets

2 Answers2

Linked