nginx 502 Bad Gateway Error


A routine software update on the server running nginx was done. After that the website stopped opening in the browser window and 502 Bad Gateway error along with the nginx version number was displayed. Looking in the log file showed an entry like,

2014/06/26 11:09:53 [crit] 2539#0: *15 connect() to unix:/tmp/php-fpm.sock failed (13: Permission denied) while connecting to upstream, client:, server:, request: "GET /foo HTTP/1.1", upstream: "fastcgi://unix:/tmp/php-fpm.sock:", host: ""


The problem was solved after the following lines were un-commented in the file, /etc/php5/fpm/pool.d/www.conf

listen.owner = www-data = www-data

The same file, /etc/php5/fpm/pool.d/www.conf, had the lines

user = www-data group = www-data

Also, the nginx configuration file /etc/nginx/nginx.conf had the user and group settings,

user www-data www-data;

See also