I've seen a number of questions here that highlight random 502 (Nginx + PHP-FPM = "Random" 502 Bad Gateway) and similar time outs when using Nginx + PHP-FPM.

Even with all the questions, I'm still unable to find a solution.

Using Ubuntu 10.10 + Nginx + PHP5-FPM + APC and every 1 out of 4 requests ends in a timeout and failure. This isn't a load issue or large traffic, it happens even in dev environment with one person.

I am doing this across 3 1GB machines, each with the same configurations and same problems.

fastcgi_params

fastcgi_param  QUERY_STRING       $query_string;
fastcgi_param  REQUEST_METHOD     $request_method;
fastcgi_param  CONTENT_TYPE       $content_type;
fastcgi_param  CONTENT_LENGTH     $content_length;

fastcgi_param  SCRIPT_NAME        $fastcgi_script_name;
fastcgi_param  REQUEST_URI        $request_uri;
fastcgi_param  DOCUMENT_URI       $document_uri;
fastcgi_param  DOCUMENT_ROOT      $document_root;
fastcgi_param  SERVER_PROTOCOL    $server_protocol;

fastcgi_param  GATEWAY_INTERFACE  CGI/1.1;
fastcgi_param  SERVER_SOFTWARE    nginx/$nginx_version;

fastcgi_param  REMOTE_ADDR        $remote_addr;
fastcgi_param  REMOTE_PORT        $remote_port;
fastcgi_param  SERVER_ADDR        $server_addr;
fastcgi_param  SERVER_PORT        $server_port;
fastcgi_param  SERVER_NAME        $server_name;

fastcgi_param  REDIRECT_STATUS    200;

/etc/php5/fpm/main.conf

; FPM Configuration ;

;include=/etc/php5/fpm/*.conf

; Global Options ;

pid = /var/run/php5-fpm.pid

error_log = /var/log/php5-fpm.log

;log_level = notice

;emergency_restart_threshold = 0

;emergency_restart_interval = 0

;process_control_timeout = 0

;daemonize = yes

; Pool Definitions ; 

include=/etc/php5/fpm/pool.d/*.conf

/etc/php5/fpm/pool.d/www.conf

[www]
listen = 127.0.0.1:9000

;listen.backlog = -1
;listen.allowed_clients = 127.0.0.1
;listen.owner = www-data
;listen.group = www-data
;listen.mode = 0666

user = www-data
group = www-data

;pm.max_children = 50
pm.max_children = 15
;pm.start_servers = 20
pm.min_spare_servers = 5
;pm.max_spare_servers = 35
pm.max_spare_servers = 10
;pm.max_requests = 500
;pm.status_path = /status

;ping.path = /ping
;ping.response = pong

request_terminate_timeout = 30
;request_slowlog_timeout = 0

;slowlog = /var/log/php-fpm.log.slow

;rlimit_files = 1024
;rlimit_core = 0

;chroot = 

chdir = /var/www

;catch_workers_output = yes