Multi Level Nodebalancer
Is it possible to set Nodebalancer at multiple network levels?
1) First Nodebalancer accepts external traffic and routes traffic to the nearest web server.
2) At second level, nodebalancer accept traffic from the web server in 1) and routes traffic between two app servers (redundancy).
A NodeBalancer can only route traffic to a private IP, and when you create a NodeBalancer, Linode will only tell you what its public IP is. As a result, you can't route traffic from one NodeBalancer to another.
Instead, you can set up load balancing software (like HAProxy or NGINX) on your own Linodes. Linode has a guide for setting up HAProxy here: