Spring Cloud Spring Cloud Service Discovery & Registration 1 — Questions and Answers
Question 1: Which Spring Cloud component provides service registration and discovery using Netflix Eureka?
- Spring Cloud Config
- Spring Cloud Netflix Eureka (Correct answer)
- Spring Cloud Gateway
- Spring Cloud Sleuth
Correct answer: Spring Cloud Netflix Eureka
Spring Cloud Netflix Eureka provides a service registry where microservices register themselves and discover other services.
Question 2: What annotation is used to enable a Spring Boot application to act as a Eureka Server?
- @EnableEurekaClient
- @EnableDiscoveryClient
- @EnableEurekaServer (Correct answer)
- @EnableServiceRegistry
Correct answer: @EnableEurekaServer
@EnableEurekaServer placed on the main application class activates the Eureka Server auto-configuration.
Question 3: What is the default interval at which Eureka clients send heartbeats to the server?
- 10 seconds
- 30 seconds (Correct answer)
- 60 seconds
- 5 seconds
Correct answer: 30 seconds
By default, Eureka clients send a heartbeat every 30 seconds to renew their lease with the server.
Question 4: Which property disables Eureka registration for a Spring Boot service during local development?
- eureka.client.fetch-registry=false
- eureka.client.register-with-eureka=false (Correct answer)
- eureka.server.enabled=false
- spring.cloud.discovery.enabled=false
Correct answer: eureka.client.register-with-eureka=false
Setting eureka.client.register-with-eureka=false prevents the service from registering itself with the Eureka server.
Question 5: What mechanism does Spring Cloud use to support multiple service discovery backends like Eureka, Consul, and Zookeeper through a single API?
- Service Mesh
- DiscoveryClient abstraction (Correct answer)
- ServiceLocator pattern
- BeanDefinitionRegistry
Correct answer: DiscoveryClient abstraction
Spring Cloud's DiscoveryClient interface provides a vendor-neutral abstraction that works with Eureka, Consul, Zookeeper, and other backends.
Question 6: In Eureka's self-preservation mode, what triggers the server to stop evicting instances?
- CPU usage exceeds 80%
- Received heartbeats fall below the expected threshold (Correct answer)
- More than 10 instances are registered
- Network latency exceeds 500ms
Correct answer: Received heartbeats fall below the expected threshold
Eureka activates self-preservation mode when the percentage of received heartbeats drops below the expected threshold, preventing mass eviction during network partitions.
Spring Cloud Spring Cloud Service Discovery & Registration 1
Which Spring Cloud component provides service registration and discovery using Netflix Eureka?