502 Bad Gateway ...来自上游服务器的无效响应（apache和jboss）

I'm using apache on one machine to serve requests to jboss on another machine. Everything works fine when I startup jboss and I'm able to access the web app, but after a few hours I eventually start getting "The proxy server received an invalid response from an upstream server" errors. If I restart jboss then everything works fine again, but several hours later I have the same issue...I'm using apache on one machine to serve reques