Possibility of JAS clustering later after deployment

According to the limitations mentioned in the below link, it is not possible clustering after deployment.

https://jazz.net/wiki/bin/view/Deployment/PerformanceClusteredJAS

The restrictions described in the https://jazz.net/wiki/bin/view/Deployment/PerformanceClusteredJAS article are due to the fact that we do not support moving the JAS data from a Derby backend to a shared database server.

If you initially set up up your Jazz Authorization Server using a DB2 or Oracle backend and fronted by an IBM HTTP Server as shown in the diagram from that article, then you should be able to start with a single Jazz Authorization Server and add additional servers later.

I would consider to go through the install/upgrade guides and see how JAS clustering is done. Usually you should be able to change the topology e.g. by introducing a reverse proxy.

Worst case I would assume you throw away JAS and set it up clustered from scratch.