This suggests either a bug in the Apache or Tomcat server, or a failure in your network equipment.
1> Fiddler got a request from the client.
2> It sent it to the server over an existing connection.
3> It began to listen for a response.
4> Before the response was received, the server connection was closed or was reset.
5> Fiddler created a new connection to the server
6> Fiddler sent the request and most likely (unless the response shows HTTP/502) got the response shown in Fiddler.
Check out the Telerik Platform - the only platform that combines a rich set of UI tools with powerful cloud services to develop web, hybrid and native mobile apps.