Error 502 in nginx + php5-fpm
fastcgi, nginx, php
Solution
The issue is socket itself, its problems on high-load cases is well-known. Please consider using TCP\IP connection instead of unix socket, for that you need to make these changes:
- in php-fpm pool configuration replace `listen = /var/run/php5-fpm.sock` with `listen = 127.0.0.1:7777`
- in /etc/nginx/php_location replace `fastcgi_pass unix:/var/run/php5-fpm.sock;` with `fastcgi_pass 127.0.0.1:7777;`
Problem
I have some error with subj. Server doesn't high loaded: ~15% CPU, there are several Gb of memory, HDD is not buisy. But error 502 throws approximately in 3% of cases. Programs: Debian 6, nginx/0.7.62, php5-fpm (5.3.3-1). In error.log of nginx is this error: ``` connect() to unix:/var/run/php5-fpm.sock failed ``` State of php5-fpm usually like this: ``` accepted conn: 41680 pool: www process manager: dynamic idle processes: 258 active processes: 1 total processes: 259 ``` I think, this mean loading is not high. I have increased backlog params: in sysctl - net.core.somaxconn = 5000, in php-fpm pool - listen.backlog = 5000. No effect. I quote a configuration: /etc/nginx/nginx.conf ``` user www-data; worker_processes 8; timer_resolution 100ms; worker_rlimit_nofile 20240; worker_priority -5; error_log /var/log/nginx/error.log; pid /var/run/nginx.pid; events { worker_connections 2048; use epoll; # multi_accept on; } http { include /etc/nginx/mime.types; access_log /var/log/nginx/access.log; sendfile on; tcp_nopush on; #keepalive_timeout 0; keepalive_timeout 65; tcp_nodelay on; gzip on; gzip_min_length 1100; gzip_buffers 64 8k; gzip_comp_level 3; gzip_http_version 1.1; gzip_proxied any; gzip_types text/plain application/xml application/x-javascript text/css; gzip_disable "MSIE [1-6]\.(?!.*SV1)"; include /etc/nginx/conf.d/*.conf; include /etc/nginx/sites-enabled/*; client_max_body_size 100M; server_tokens off; } ``` /etc/nginx/php_location ``` fastcgi_pass unix:/var/run/php5-fpm.sock; fastcgi_index index.php; fastcgi_param SCRIPT_FILENAME $document_root/$fastcgi_script_name; fastcgi_buffers 256 128k; #fastcgi_buffer_size 16k; #fastcgi_busy_buffers_size 256k; fastcgi_connect_timeout 300s; fastcgi_send_timeout 300s; fastcgi_read_timeout 300s; include fastcgi_params; ``` php-fpm pool ``` [www] listen = /var/run/php5-fpm.sock listen.backlog = 5000 listen.owner = www-data listen.group = www-data listen.mode = 0666 user = www-data group = www-data pm = dynamic pm.max_children = 1024 pm.start_servers = 64 pm.min_spare_servers = 64 pm.max_spare_servers = 128 pm.max_requests = 32000 pm.status_path = /system/php5-fpm-status slowlog = /var/www/log/php-fpm.log.slow chdir = /var/www ``` What can I do to optimize this system and make this use all server resources? PS. I'm sorry, my english is bad.