So we now know a little more of how Hazelcast apportions data into partitions, how these partitions are automatically assigned to a node or a partition group and how we might configure these to our needs. We have also investigated how it deals with issues, be it failure of an individual node or group of nodes within a defined silo, and how we recover it to restore resilience; or an underlying network fabric issue that creates a network split brain, and how we are able to cleanly bring multiple sides of the split back together and return to normal service.

Now that we have seen how things work behind the scenes to manage and distribute our data, we might need our application to know about some of these goings-on. In the next chapter we shall look at how our application can register its interest to be notified as things happen to support the cluster.