apache 反向代理 iis 502 proxy error：报错

最近服务器发生一怪事  之前搭建环境时  用apache反向代理 iis时是处理过这个问题的 

Proxy Error

The proxy server received an invalid response from an upstream server.
The proxy server could not handle the request GET /.

Reason: DNS lookup failure for: hehe.amd2015.com

当时也是按照网上的方法在我的vhosts.conf内直接加入了

ProxyRequests Off
<Proxy *>
Order deny,allow
Allow from all
</Proxy>

SetEnv force-proxy-request-1.0.1

SetEnv proxy-nokeepalive 1

然后服务器正常运行了数月，直到前两天又莫名出现了这个问题，

eg：下面这个二级域名的配置

<VirtualHost *:80>
    ServerAdmin Snooker.amd2015.com
    DocumentRoot "X:\XXXXX\XXXX\wwwroot"
    ServerName Snooker.amd2015.com
ProxyPass / http://Snooker.amd2015.com:81/
    ProxyPassReverse / http://Snooker.amd2015.com:81/
ErrorLog "logs/Snooker.amd2015.com-error.log"
    CustomLog "logs/Snooker.amd2015.com-access.log" common
SetEnv force-proxy-request-1.0.1
SetEnv proxy-nokeepalive 1
</VirtualHost>

但是这次奇怪的就在如果配置的是正式域名的就能正常访问，

eg：

<VirtualHost *:80>
    ServerAdmin www.jyzsjj.com
    DocumentRoot "X:\XXXXX\XXXX\wwwroot"
    ServerName www.jyzsjj.com
ProxyPass / http://www.jyzsjj.com:81/
    ProxyPassReverse / http://www.jyzsjj.com:81/
ErrorLog "logs/jyzs.amd2015.com-error.log"
    CustomLog "logs/jyzs.amd2015.com-access.log" common
SetEnv force-proxy-request-1.0.1
SetEnv proxy-nokeepalive 1
</VirtualHost>

这里是error.log:

[Fri May 22 13:48:48.504381 2015] [proxy:error] [pid 7428:tid 2864] [client xxx.xxx.xxx.xxx:xxx] AH00898: DNS lookup failure for: snooker.amd2015.com returned by /
[Fri May 22 13:48:48.555159 2015] [proxy:error] [pid 7428:tid 2864] [client xxx.xxx.xxx.xxx:xxx] AH00898: DNS lookup failure for: snooker.amd2015.com returned by /favicon.ico, referer: http://snooker.amd2015.com/