我們在使用nginx的時候有不少問題出現，首先我們就來解決下nginx 502錯誤的問題

經 過分析將nginx的error log打開，發現”pstream sent too big header while reading response header from upstream”這樣的錯誤提示，查閱了一下資料，大意是nginx緩沖區有一個bug造成的,我們網站的頁面消耗占用緩沖區可能過大

我們是nginx反向代理
proxy是nginx作為client轉發時使用的，如果header過大，超出了默認的1k，就會引發上述的upstream sent too big header （說白了就是nginx把外部請求給后端apache ，apache返回的header  太大nginx處理不過來就導致了。

server {
        listen       80;
        server_name  *.xywy.com ;

       large_client_header_buffers 4 16k;

       #charset koi8-r;

       # access_log off;

       location / {

#添加這3行 ，
                proxy_buffer_size 64k;
                proxy_buffers   32 32k;
                proxy_busy_buffers_size 128k;

          proxy_set_header Host $host;
           proxy_set_header X-Real-IP       $remote_addr;
           proxy_set_header X-Forwarded-For  $proxy_add_x_forwarded_for;

          set $baiduspider '';

          if ( $http_user_agent ~ Baiduspider) {
              set $baiduspider Baidu;
          }

............

如果是 nginx+PHPcgi 就該 

fastcgi_connect_timeout 60;
fastcgi_send_timeout 180;
fastcgi_read_timeout 180;
fastcgi_buffer_size 128k;
fastcgi_buffers 4 256k;
fastcgi_busy_buffers_size 256k;
fastcgi_temp_file_write_size 256k;
fastcgi_intercept_errors on
011/01/07 11:12:57 [error] 10770#0: *38585340 upstream timed out (110: Connection timed out) while reading response header from upstream, client: 116.22.131.154, server: *.xywy.com, request: "GET /ysmp/index.php?did=124994 HTTP/1.0", upstream: "http://127.0.0.1:8080/ysmp/index.php?did=124994", host: "xywy.yn16.com"
 

后來原來那錯誤沒了出了新錯誤了 upstream timed out 超時？

server {
        listen       80;
        server_name  *.xywy.com ;
  large_client_header_buffers 4 16k;
        client_max_body_size 300m;
        client_body_buffer_size 128k;
        proxy_connect_timeout 600;
        proxy_read_timeout 600;
        proxy_send_timeout 600;
                proxy_buffer_size 64k;
                proxy_buffers   4 32k;
                proxy_busy_buffers_size 64k;
            

關鍵詞：nginx