Spring Cloud Eureka 1 (Eureka introduction)

Spring Cloud Eureka is part of the spring cloud Netflix MicroServices Suite, which has two packages based on Netflix Eureka and is primarily responsible for service governance capabilities in the MicroServices architecture.

Service governance:

Service governance can be said to be the most core and basic module in the micro-service architecture, it mainly realizes the automatic registration and discovery of each micro-service instance.

Why is there a need for service governance, and what happens without it?

In the early stages of system construction, the number of services is low we can do a call to the service through some static configuration.

For example, there are two services A and B where service a needs to invoke service B to complete a business operation, in order to improve the performance or high availability of B we will launch multiple instances for B, so that we need to manually maintain the specific instance list of B.

As our systems become more and more service more and more of this work becomes cumbersome and tedious to maintain.

The automation management of micro-service Application example mainly revolves around the two concepts of service registration and service Discovery .

Service registration:

In the service governance framework, a registry is typically built, each service unit registers its own services with the registry, notifies the registry of hosts and ports, version numbers, and so on, and the registry organizes the list of services by service name.

For example, we have two processes that provide a service running in 10.237.43.1:080 and 10.237.43.2:8080 respectively, when the process starts, the registry maintains a list like this.

Service Name Location

Service a 10.237.43.1:8080, 10.237.43.2:8080

Service discovery:

Because of the presence of the service registry, calls between services initiate requests to the service instance through the service name. Therefore, the service caller does not know the exact location of the service when making the service call.

Therefore, the caller needs to get a specific list of the services being invoked to the service center. If service B wants to invoke service A above, service B will request a specific list of a from the service registry, 10.237.43.1:8080 and 10.237.43.2:8080

When b wants to initiate a call, it takes a location from the manifest with some sort of polling policy to make the service call.

Eureka is divided into server side and client

The service side we also call the service registry, and the client mainly completes the service registration and discovery.

Spring Cloud Eureka 1 (Eureka introduction)