nginx can be used as both: as a HTTP server and as a load balancer. In this screencast I used nginx to balance the load between two TomEE instances.
The Docker images in this screencast were borrowed from: https://github.com/AdamBien/docklands
Also checkout load balancing with HAProxy: • Load Balancing Java EE Microservices
See you at http://airhacks.com, http://airhacks.io or at least at http://airhacks.tv :-)