Computer Programming: 504 Gateway Timeout Error

Problem: My load balancer machine is giving me 504 Gateway Timeout Error.

HTTP request flow :

Browser <-> nginx(load balaencer on port 80) <-> Apache ( reverse proxy on port 85) <-> haproxy (load balaencer on 7070) <-> Tomcat ( Servlet Enginge 8080)

When I am accessing resource http://www.mydomain.com/helloworld/hello.jsp I receive 504 Gateway Timeout Error gateway time out. I am clue less which server is sending this error. I verified the logs of ngnix,apache,haproxy,tomcat none of them revel evident root cause.

Approach Taken to solve the Problem:

Let’s access the resource from bottom to top

http://tomcat-ip:8080 /helloworld/hello.jsp (Resource is served in 5min. No time out)

http://haproxy-ip:7070 /helloworld/hello.jsp (Resource time out )

http://Apache-ip:8585 /helloworld/hello.jsp (Received 504 Gateway time out)

http://nginx:80 /helloworld/hello.jsp (Received 504 Gateway time out)

We identified the root cause for this problem is haproxy and we need to increase the load_balancer time out of it.

Solution: