Apache Web Server not communicating with the backend tomcat 6 serer in Eclipse

I am trying to do a project setup and we have 2 servers for it 1) frontend server: Apache Web server (runs on port 80 [Apache/2.4.18 (Win32) OpenSSL/1.0.2e PHP/7.0.5 mod_jk/1.2.40 Server at localtest.lotus.com Port 80]) 2) backend server: Tomcat 6 in Eclipse (runs on port 8080)

both the servers are up and running on the same machine. however the communication between these servers don't work and i get this error: Service Unavailable: 503

How to get the Apache Web server to communicate with the tomcat 6 server in eclipse?

Please help!