Spring Cloud Core Concepts and Interview Questions Overview

Spring Cloud is a suite of tools built on Spring Boot for developing distributed microservices, providing features such as service registration and discovery, load balancing, circuit breaking, and configuration management.

Key concepts include the definition of microservices, advantages of Spring Cloud over plain Spring Boot, and common challenges like network latency, service discovery, redundancy, load balancing, performance, and deployment complexity.

Communication between services can be synchronous (REST, RPC) or asynchronous via message queues like RabbitMq , ActiveM , Kafka . Service resilience is achieved with circuit breakers and fallback methods using Hystrix annotations @EnableHystrix , @HystrixCommand , etc.

Eureka and Zookeeper serve as registration centers with different consistency models (Eureka – AP, Zookeeper – CP). Eureka’s self‑protection mode prevents premature deregistration during network issues.

Spring Cloud integrates components such as Eureka, Feign, Ribbon, Hystrix, Zuul, and Config Server, each providing specific functionality like client‑side load balancing, declarative REST clients, fault tolerance, API gateway, and centralized configuration.

Additional topics cover the differences between Spring Boot and Spring Cloud, the role of Spring Cloud Bus for broadcasting configuration changes, and the purpose of Spring Cloud Gateway as a modern API gateway replacing Zuul.