Spring Cloud Technology & Digital Applications 5 — Questions and Answers
Question 1: Which Spring Cloud Gateway predicate matches requests based on the value of an HTTP header?
- Query predicate
- Header predicate (Correct answer)
- Host predicate
- Cookie predicate
Correct answer: Header predicate
The Header predicate matches routes when a request contains a specified header name and optional regex-matched value.
Question 2: In Spring Cloud, what does the term 'service mesh' integration refer to when using Spring Cloud Kubernetes?
- Replacing Kubernetes DNS with Eureka
- Delegating service-to-service communication and observability to a sidecar proxy like Istio (Correct answer)
- Running Spring Boot inside a Docker Swarm
- Using Spring Cloud Gateway as a Kubernetes Ingress controller
Correct answer: Delegating service-to-service communication and observability to a sidecar proxy like Istio
Service mesh integration offloads cross-cutting concerns (mTLS, retries, tracing) to a sidecar proxy such as Istio or Linkerd running alongside the Spring pod.
Question 3: Which annotation registers a Spring Boot application as a Eureka client and enables service discovery?
- @EnableEurekaServer
- @EnableFeignClients
- @EnableDiscoveryClient (Correct answer)
- @EnableCircuitBreaker
Correct answer: @EnableDiscoveryClient
@EnableDiscoveryClient registers the application with any compatible service registry (Eureka, Consul, Zookeeper) and enables lookup of other services.
Question 4: What Spring Cloud contract testing tool lets a producer define contracts that are automatically turned into consumer-side tests?
- Spring Cloud OpenFeign
- Spring Cloud Contract (Correct answer)
- Spring Cloud Task
- Spring Cloud Sleuth
Correct answer: Spring Cloud Contract
Spring Cloud Contract enables Consumer-Driven Contract testing by generating stubs and verifying producer implementations against shared contracts.
Question 5: How does Spring Cloud LoadBalancer obtain the list of available service instances by default?
- From a static list in application.yml
- From the service discovery registry (e.g., Eureka) (Correct answer)
- From Kubernetes Ingress rules
- From an external Redis cache
Correct answer: From the service discovery registry (e.g., Eureka)
Spring Cloud LoadBalancer queries the service registry to get healthy, currently registered instances before selecting one for a request.
Question 6: Which Spring Cloud Stream feature allows multiple functions to be composed into a processing pipeline?
- Binder chaining
- Function composition using the '|' pipe in spring.cloud.function.definition (Correct answer)
- Stream branching via @Input/@Output chains
- MessageChannel wiring in XML
Correct answer: Function composition using the '|' pipe in spring.cloud.function.definition
Spring Cloud Function's definition property supports function composition with '|' (pipe) notation, e.g., 'uppercase|trim', executed left to right.
Question 7: What is the primary use of the spring.cloud.config.fail-fast=true property on a Config client?
- Causes the client to skip the Config Server if it's slow
- Makes the application fail to start if it cannot connect to Config Server on boot (Correct answer)
- Disables local property fallbacks permanently
- Forces synchronous HTTP calls to the Config Server
Correct answer: Makes the application fail to start if it cannot connect to Config Server on boot
With fail-fast=true, the application throws an exception and refuses to start if Config Server is unreachable, preventing misconfigured deployments.
Spring Cloud Technology & Digital Applications 5
Which Spring Cloud Gateway predicate matches requests based on the value of an HTTP header?