Once you have made it through the application process for Spring Cloud and been called in to proceed to the interview stage, one of your top priorities will likely be your interview preparation. This article provides sample interview questions and answers that should be of immense help and guidance to you as you get ready for your interview. The content in the article comprises a set of Spring Cloud Interview Questions and sample answers you can use to impress your interviewer.
We hope this serves as a helpful guide and aid for you to be as prepared as possible for this stage of the hiring process.
Spring Cloud Interview Questions and Answers
The following are a set of interview questions that are each followed by their respective answers:
What is Spring Cloud?
Spring Cloud is a framework and an open-source library that allows integration with external systems and allows applications to connect to services and explore information in multiple clouds easily. In addition, it provides tools and libraries to develop common design patterns of distributed systems speedily.
Please list the advantages of using Spring Cloud.
- It creates ease in the development and registration of JVM services for the cloud.
- It is cloud-agnostic.
- Its service splitting optimizes development efficiency and enables resource reuse.
- It provides load balancing, which improves the distribution of workloads across several computing resources.
- It follows the Spring Boot model.
- It can more precisely configure an improved service plan and elevate the maintainability of the system.
- It provides a circuit breaker that prevents service failure from escalating by allowing an eased degradation of functionality if a service failure occurs.
- It provides inter-service communication.
- It enables decentralized thinking through its microservice architecture.
- It provides log tracing, which enables in-depth troubleshooting.
- It provides microservice-based architecture.
- It provides cloud-native-based development.
- It is fitting for the internet era and shortens the product iteration cycle.
- It has eased in implementing authorization and authentication.
Can you define Service registration and discovery and explain how Spring Cloud is implemented?
Service registration and discovery allow microservices to utilize and consume other services while leaving their locations known or unexposed. Thus, it eliminates the complications that are bound to arise when dealing with the configuration of multiple services for a project. Spring Cloud is implemented using its Eureka service registration and discovery, which has all services registered on its server. This allows service registration and discovery to easily find services through the Eureka server without needing to process service locations without needing to conduct changes.
What does load balancing mean?
Load balancing is the efficient distribution of network and application workloads across multiple servers to improve resource usage, avoid overloading single resources, reduce response time and increase throughput. In addition, it elevates reliability and helps unload computer clusters, network links, Central Processing Units (CPUs), and disk drives.
Please explain what Hystrix is and how it achieves fault tolerance.
Hystrix is a latency and fault-tolerant library typically designed for systems that utilize or are developed using numerous microservices. It isolates points of access to remote systems, services, and third parties. It achieves fault by preventing service failure from cascading and improving resilience in highly vulnerable systems to failures.
What is Spring Cloud Bus, and do we need it?
Spring Cloud Bus links microservices together for swift and distributed messaging. It can refresh the configuration of multiple services by connecting microservices to a sole message broker who can connect to all necessary modules for widespread configuration. Spring Cloud Bus is especially effective when a microservice is running. So, yes, we do need Spring Cloud Bus because it helps execute changes throughout a cluster efficiently and directly.
What is a microservice?
A microservice, also known as microservice architecture, is a unique architectural style, process, or method used to develop software systems. Microservices focuses on prioritizing the construction of components with distinctly distinguished interfaces and operations. It propagates the division of an application into a set of smaller services that go on to coordinate with one another.
Please state the differences, if there are any, between Eureka and Zookeeper?
The main similarity between Eureka and Zookeeper is that both tools provide service registration and discovery uses. However, Eureka ensures high availability, usability, a self-protection mechanism and will not paralyze the whole registration service. On the other hand, Zookeeper ensures consistency and partition fault tolerance but will, however, paralyze the whole registration service – unlike Eureka.
Please state what distinguishes Spring Boot from Spring Cloud.
Spring Boot is a tool for rapid application development that utilizes multiple Spring framework modules. It develops Restful API and microservices at an efficient and rapid pace and comes with auto-configurator, starter, and cli features. Spring Cloud focuses on the governance of microservices developed by Spring Boot by integrating them into its global microservice coordination and management framework. Spring Boot can operate independently from Spring Cloud, while Spring Cloud is dependent on Spring Boot and cannot operate independently from it.
Can you name the advantages of using microservices?
Advantages are as follows:
- They can be developed, maintained, and deployed independently.
- Microservice-based applications scale better.
- They reduce time to market, and they speed up the CI/CD pipeline, which improves agility.
- They have a better failure tolerance.
- They are easier to maintain and debug compared to complex applications.
- They have platform and language agnostic services.
- They embody cloud-readiness.
- They are cohesive and have easily understandable codes.
- They have high development efficiency.
- They are easy to integrate with third parties.
- They are flexible and can be matched and connected to public libraries and independent libraries.
Please give the disadvantages of microservices.
Disadvantages are as follows:
- They require high collaboration.
- Their complex architecture makes them harder to test and monitor.
- Their performance is poor if there are network delays because they require reliable communication to perform effectively.
- They do not work well with poor or improper corporate culture.
- They have security difficulties and weaknesses.
- They have network difficulties.
What Microservice technology stacks do you know?
- Dimensions (Spring Cloud)
- Service load balancing: Ribbon, Nginx
- Service call: Rest RPC, gRPC
- Service interface call: Feign.
- Message Queue: Kafka, RabbitMQ, and ActiveMQ
- Service registration and discovery: Eureka, Zookeeper
- Service Configuration Center Management: Spring Cloud Config
- Service development: Spring Boot, Spring, Spring MVC
- Service routing (API gateway) Zuul
- Service configuration and management: Archixius of NetFix, Diamond of Ali
- Event message bus: Spring Cloud Bus
- Service fuse: Hystrix
How do microservices communicate independently?
They use remote calls such as feign calls and directly access other services through these remote procedural calls. They also use message middleware.
How does Spring Cloud register services?
Once the service is published, you must specify its corresponding service name and register it to the registration center, Eureka, or Zookeeper. Next, the registration center adds the service registration and discovery type you have chosen. The registration center then utilizes Ribbon or Feign to execute service direct call discovery.
What is Eureka’s self-protection mechanism?
Eureka’s self-protection mechanism protects registration information, aborts the deleting of registration data, and methodically exits when the Eureka Server loses numerous instances of connection in a short period of time.
What is Ribbon?
Ribbon is a client that is used in load balancing. It can govern and direct the way http and tcp behave.
Please state what Feign is.
Feign is a web service module that incorporates Ribbon to execute the ability to load balance. It uses interface-based annotations.
What is the difference between Ribbon and Feign?
The ribbon has a tedious calling method as it has to construct and simulate its HTTP request on its own and sends it to other services through RestTemplate, while Feign defines the calling method as an abstract method. Moreover, they both have different startup class annotations and different locations as specified by the service. Finally, Ribbon can call other services in different ways.
What is Spring Cloud Gateway?
Spring Cloud Gateway is a second-generation gateway. It is an important part of the system that performs current limit control, permission verification, and routing and forwarding. The gateway serves as an official replacement for Zuul Gateway.
What is Ribbon load balancing?
Ribbon load balancing is brought about by load balancing tools that provide a series of configuration items that list the machines behind a Load Balancer in the configuration file. It helps connect the listed machines according to certain selected rules and eases the implementation of custom load algorithms.
What is the function of Ribbon load balancing?
Ribbon balancing can distribute a user’s request to a multitude of servers in equal measure.
Please explain what the Zuul routing gateway is?
Zuul routing gateway carries the responsibility of transmitting external orders to specified microservice conditions. It also carries out filtering and processes negative requests to help implement request verification and service aggregation, among other functions.
That brings an end to the sample interview questions and answers that we think will help you prepare for your interview for Spring Cloud. All the best with your interview!