Apache proxypass solution with 503 service temporarily unavailable Error

-- Apache configuration
<Virtualhost *: 80>
Servername www.mydomain.com
Proxyrequests off
<Proxy *>
Order deny, allow
Allow from all
</Proxy>
Proxypass/http: // 192.168.168.132: 8089/
Proxypassreverse/http: // 192.168.168.132: 8089/
</Virtualhost>

-- Access http://www.mydomain.com/error message
Service temporarily unavailable

The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later.

-- View error logs
# Tail/var/log/httpd/error_log
[Fri Mar 08 16:38:14 2013] [Error] (13) Permission denied: proxy: http: attempt to connect to 192.168.168.132: 8089 (192.168.168.132) failed
[Fri Mar 08 16:38:14 2013] [Error] ap_proxy_connect_backend disabling worker for (192.168.168.132)

-- Guess the influence of SELinux
#/Usr/sbin/getsebool-A | grep httpd_can_network_connect
Httpd_can_network_connect -->Off
Httpd_can_network_connect_cobbler --> off
Httpd_can_network_connect_db --> off

-- Set httpd_can_network_connect to on
#/Usr/sbin/setsebool-P httpd_can_network_connect = 1
#/Usr/sbin/getsebool-A | grep httpd_can_network_connect
Httpd_can_network_connect -->On
Httpd_can_network_connect_cobbler --> off
Httpd_can_network_connect_db --> off

Access http://www.mydomain.com/again, everything is OK.

Disable SELinux.
1) Modify/etc/SELinux/config and restart
SELinux = disabled
2) #/usr/sbin/setenforce 0 takes effect in real time