In monomer type service, usually by multiple clients to invoke a service, as long as the only service node configuration in the client address, after upgrading to a distributed service node more, like more than a wire service node is a consortium of thousands of ali, so many nodes cannot be manually configured on the client side, here need an intermediate service, Designed to help clients discover service nodes, service discovery is often referred to in many technical books.
A complete registry covers the following features:
L Service registration: providers submit their own services to the registry when they go online.
L Service logout: notifies the registry provider to go offline.
L Service subscription: receive service change messages dynamically and in real time.
Reliable: The registration service itself is clustered and data is stored redundantly. Avoid single point of failure and data loss.
Fault tolerance: The registry can dynamically sense and notify clients of the status of a service provider in the event of downtime, power outages, etc.