PHP-FPM and Nginx Upstream Configuration

Most nginx / php-fpm tutorials you'll find nowadays recommend to create an nginx upstream configuration that listens on localhost port 9000.

upstream php {
    server 127.0.0.1:9000;
}

If you're using a current version of Debian and php5-fpm from dotdeb, this won't work though and you'll see the following error message in your nginx log:

2013/05/25 00:12:04 [error] 17672#0: *76 connect() failed (111: Connection refused) while connecting to
upstream, client: 2a02:1205:5050:8530:c5f6:250c:ffa0:4d49, server: example.com, request: "GET /index.php
HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "example.com"

This is because the dotdeb version seems to have changed the default configuration from the IP based version to a unix domain socket. You can grep for the important line in your configuration:

danilo@server:~$ grep -ri "listen = " /etc/php5/fpm/
/etc/php5/fpm/pool.d/www.conf:listen = /var/run/php5-fpm.sock

To be on the safe side, you can also test whether any process is listening on port 9000:

danilo@server:~$ sudo lsof -i tcp:9000
danilo@server:~$

It's trivial to adjust the nginx configuration accordingly:

upstream php {
    server unix:/var/run/php5-fpm.sock;
}

Simply restart nginx and everything should be working.