Take a look at this quick demo to see some of Payara Micro's  dynamic clustering capabilities. I'm running the demo without any extra tools, just Payara Micro itself. To show how Payara Micro dynamically rebalances the cluster, I used JCache and Payara Micro's --autoBindHttp feature.

If you want to try it youself, you can use a very simple application, the same I've used for this demo, which is available to download in the Payara examples repository on GitHub