在尤里卡注册我的配置服务器有什么用吗？

Question

I'm specifying the config server URI spring.cloud.config.uri in the bootstrap.properties file of all my config server clients.

So is there any use of adding an @EnableDiscoveryClient annotation to it, and registering the configuration service in Eureka?

Answer 1

There are various use cases why registering your config server on Eureka could be useful:

Discovery-first bootstrapping

When using the Spring cloud config service, you have two choices when bootstrapping your application, as mentioned by the documentation :

1. Using a config-first setup (default)
2. Using a discovery-first setup

When you use a discovery-first setup, all applications can retrieve their configuration by looking up the URL of the configuration service on Eureka:

spring.cloud.config.discovery.enabled=true
spring.cloud.config.uri=http://config-service

In this case, the application will look for a service named config-service on Eureka, and will use the given hostname and port to connect.

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Discoverability

Some tools, like Zuul, Spring boot admin, ... will automatically discover all applications and use them, for example:

• Spring boot admin can be setup to automatically discover all applications to manage them.
• Zuul will automatically forward all routes matching /{application-name}/** to the given application.

Answer 2

@EnableDiscoveryClient activates the Netflix Eureka DiscoveryClient implementation and tells it to register itself with a service registry.

So, without this annotation, your application will not able to register itself to any Registry. And hence will not be discovered from any service as well.

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Edit : Registering your application to DiscoveryServer provides many benefits, some of them are below :

• Application independence : When you register your application to DiscoveryServer it decouples it from another application. Doing so you don't need to hardcode the name and URL of your application in using application.
• Load Balancing : Register your application to DiscoveryServer provides an effective and efficient way to provide load balancing.
• Multiple instances of same application : In order to provide load balancing you can add multiple instances of a single application.
• Resilience : When an instance is not working then Server can use the circuit breaker to handle requests effectively and helps in making system responsive and resilient.