There are some things in the game that really aren’t good to handle with REST APIs. Reacting to events is a much more efficient way of propagating changes through the system. For example, when a player changes their name via the Player service, that change should ripple out to all interested parties so that interactions across devices can be updated with the new username.

We decided to try using Kafka, or, when we run in BlueMix, MessageHub (which has a Kafka interface, so essentially it’s still Kafka to us). As we looked more into Kafka we realised we can only allow our core services to make use of it. While we would really like to make it generally accessible, it wasn’t really built to be internet facing (It only started to add security at version 0.9). Maybe some day…​

We wrapped our handling of receieved events into an RxJava based API, just by the way. That’s worth a look or three.

We’re still in early days with our integration of Events, but the infrastructure is all there waiting for us to use it.