日期:2014-05-17  浏览次数:20963 次

apache 的http代理出错 502 Proxy Error

不久刚部署好的网站,忽然访问报错提示错误


Http 502 Proxy Error
The proxy server received an invalid response from an upstream server.
The proxy server could not handle the request GET /.
Reason: Error reading from remote server


看了半天也没看出个所以然来, 刚刚还好好的呢!过了一会网站又能打开了....
查看了一下apache 的access_log。发现

.....Get / HTTP/1.0....

这是ie5.5以下的版本访问过。所以又找来台ie5.5(挺难整,这年头这玩意少了!!)访问了一下,然后出错。在用别的机器访问错误还有。在刷新了一会又好了!
就这个问题Google了一下发现是mod_proxy的事,又G了一下他的文档
http://httpd.apache .org/docs/2.3/mod/mod_proxy.html
找到了这一段话

For circumstances where mod_proxy is sending requests to an origin server that doesn't properly implement keepalives or HTTP/1.1, there are two environment variables that can force the request to use HTTP/1.0 with no keepalive. These are set via the SetEnv directive.
These are the force-proxy -request-1.0 and proxy -nokeepalive notes.

译了一下大概是这意思(不是我译的)

当mod_proxy向一个没有正确实现持久连接(KeepAlive)或HTTP/1.1的原始服务器发送请求的时候,可以通过设置两个环境变量来发送不带持久连接(KeepAlive)的HTTP/1.0请求。这两个变量是通过SetEnv指令设置的。
以下是force-proxy -request-1.0和proxy -nokeepalive的例子:
<Location /buggyappserver/>
  ProxyPass http://buggyappserver:7001/foo/

SetEnv force-proxy-request-1.0 1
SetEnv proxy-nokeepalive 1
</Location> 

最后在我的httpd.conf的VirtualHost里加上了上面的两行设置

<VirtualHost *:80> 
   JkMount /hr/servlet/* worker1 
   JkMount /hr/*.jsp worker1 
   JkMount /hr/*.do worker1 
   ServerAdmin njgnini@163.com 
   ServerName www.iteye.com 
   ServerAlias www.iteye.com.cn 
   RewriteEngine On 
   RewriteRule ^/$ /hr/ [R,P]       
   
SetEnv force-proxy-request-1.0.1 
SetEnv proxy-nokeepalive 1
?</VirtualHost> 


重启apache ,在拿ie5.5访问O了