Mechanism for service discovery

Features provided by the CoreOS services etcd and fleetd can be used to discover services. The following figure explains the typical mechanism used for service discovery:

In the previous chapters, we have seen how etcd and fleetd can be used to discover the member nodes in a cluster. The etcd service is not limited for node discovery. It can be used to discover or publish information related to applications or services. The subsequent sections in this chapter cover how to publish and discover service-related information using etcd.

There are two kinds of member nodes in the cluster: frontend service nodes and backend service nodes.

• The frontend service handles all service requests and routes the request to the backend service for actual processing. This is the simplified but typical architecture for any high-capacity system. In the frontend service nodes, the following services will be running:
  • Discovery service
  • etcd service
  • fleetd service
  • Frontend or route service...