Nginx 出現 500 Error 修復 (too many open file, connection)

网络浪子

　　Nginx 出現 500 Error, 錯誤訊息只能從 Log 查到, 有遇到下述兩種狀況:

• socket() failed (24: Too many open files) while connecting to upstream
  
• 512 worker_connections are not enough while connecting to upstream
  

　　在此紀錄解決方法.
Nginx "Too many open files" 修復
錯誤訊息

　　2011/05/01 23:00:49 [alert] 7387#0: *6259768 socket() failed (24: Too many open files) while connecting to upstream, client: 123.123.123.123, server: www.example.com, request: "GET [[/]] HTTP/1.1", upstream: "fastcgi://127.0.0.1:1234", host: "www.example.com"

解法

• $ ulimit -n # 看目前系統設定的限制 (ulimit -a # 可查看全部參數)

  　　1024
  

  
  
• vim /etc/security/limits.conf # 由此檔案設定 nofile (nofile - max number of open files) 的大小

  　　# 增加/修改 下述兩行
  　　* soft nofile 655360
  　　* hard nofile 655360
  

  
  
• ulimit -n # 登出後, 在登入, 執行就會出現此值

  　　655360
  

  
  

Nginx "512 worker_connections are not enough" 修復
錯誤訊息

　　2011/05/01 23:21:21 [alert] 19973#0: *6325881 512 worker_connections are not enough while connecting to upstream, client: 123.123.123.123, server: www.example.com, request: "GET / HTTP/1.1", upstream: "fastcgi://127.0.0.1:1234", host: "www.example.com"

解法

• /etc/nginx/nginx.conf

  　　worker_connections  10240;
  

  
  
• 參考 Nginx CoreModule

  　　worker_processes 2;
  　　worker_rlimit_nofile 10240;
  　　events {
  　　# worker_connections 10240;
  　　}
  

  
  

　　Nginx 的 connection 增加後, 整體速度會變慢很多, 主要原因是 php-cgi 不夠用, 所以要作以下調整.

　　php-cgi was started with phpfcgid_children="10" and phpfcgid_requests="500"
　　ab was run on another server, connect via a switch using GBit ethernet

　　參考此篇設定: PHP performance III -- Running nginx

• vim /etc/nginx/nginx.conf

  　　worker_connections 10240;
  　　worker_rlimit_nofile
  

  
  
• vim /etc/init.d/php-fcgi

  　　PHP_FCGI_CHILDREN=15
  　　PHP_FCGI_MAX_REQUESTS=1000
  　　改成
  　　PHP_FCGI_CHILDREN=150
  　　PHP_FCGI_MAX_REQUESTS=10240
  

  
  
• 上述文章的 phpfcgid_stop(), 寫得還不錯, 有需要可以用看看.

  　　phpfcgid_stop() {
  　　echo "Stopping $name."
  　　pids=`pgrep php-cgi`
  　　pkill php-cgi
  　　wait_for_pids $pids
  　　}