The next component that we are going to look at, which is available alongside the cache, is the Registrator (http://gliderlabs.github.io/registrator/latest/). The Registrator is a third-party service registration tool that basically watches for startup and shutdown events of microservices and, based on the output of those events, dynamically updates the centralized service registry. Different services can then directly communicate with the registry to get updated locations of services. The Registrator ensures that registration and deregistration code is not duplicated across systems. We will look at this in more detail in Chapter 6, Service Registry and Discovery, where we integrate the Registrator with the consul.