Microservice Architectures - Introduction to Spring Cloud


Image


CHECK OUT OUR 8 AMAZING AWS CERTIFICATION COURSES HERE


In this article, we focus on Spring Cloud. We talk about the various components under its umbrella.

You will learn

  • What is Spring Cloud?
  • What are the typical challenges in microservices architectures?
  • What are the challenges that Spring Cloud solves?
  • What are the important projects under Spring Cloud umbrella?
  • How does Spring Cloud help you build your microservices architecture?

Free Courses - Learn in 10 Steps

Introduction to Cloud, Microservice - Challenges and Advantages

This is the second article in a series of five articles on cloud and microservices:

Introducing Spring Cloud

If you go to the homepage of Spring Cloud:

image info

Spring Cloud provides tools for developers to quickly build some of the common patterns in distributed systems (e.g. configuration management, service discovery, circuit breakers, intelligent routing, micro-proxy, control bus, one-time tokens, global locks, leadership election, distributed sessions, cluster state)

Spring Cloud is not a single project, rather a cluster of them.

Shown below is just a small sample of the projects present under this umbrella.

image info

Let’s get a quick introduction to some of the important projects under Spring Cloud umbrella

Spring Cloud Netflix

Netflix was one of the first organizations to play around with microservices architecture. Under this project, a large number of projects have been open sourced for public use. Eureka, Hystrix and Zuul are popular ones among them.

Spring Cloud Config

This project provides a framework for centralized configuration management, making use of a Git or a SVN repository.

Spring Cloud Bus

This enables the microservices and infrastructure components to communicate with each other, in a distributed setup.

Challenges in Microservices Architectures

Let’s now have a look at the challenges we face while developing microservices applications, and the solutions offered by Spring Cloud for them.

Configuration Management

In a system with a microservices architecture, there are a large number of small-sized microservices that communicate with each other:

image info

Each of these microservices needs to execute across multiple environments. In a given environment, there could be multiple instances of that microservice running. This means the operations team needs to manage a lot of configuration information for each microservice.

The Spring Cloud Config Server provides a solution to such configuration management

image info

It provides an approach, where all the configurations across environments for all the microservices, is stored in a Git repository. The Spring Cloud Config Server then exposes this information to all the microservices.

Storing the configurations in such a centralized location makes it easier for the operations team to manage it.

Dynamic Scale Up And Down

Consider the following example:

The CurrencyCalculationService microservice talks to another microservice, the CurrencyExchangeService. Currently, three instances of CurrencyExchangeService are running. it is possible that at any point in time, more instances can be added in, or existing instances can be removed.

image info

We need the CurrencyCalculationService to be able to distribute the load across the instances available at that point in time.

The need is to dynamically find out the number of instances of the CurrencyExchangeService at that time, and distribute the load across them.

Solution involves multiple components.

Service Registration

All microservices register with a naming server. One of the options Spring Boot provides is Eureka.

Service Discovery

When any microservice wants to talk to another microservice, it asks the naming server In the example above, the CurrencyCalculationService can ask the Eureka naming server, about the instances of the CurrencyExchangeService that are running. The naming service would, in turn, provide the URLs of those instances back to the CurrencyConversionService.

This helps establish a dynamic relationship between instances of the communicating microservices.

Load Balancing

When there are multiple instances of same microservice, you want to distribute load between them. One of the options Spring Cloud provides is a client side load balancing framework, Ribbon.

The CurrencyCalculationService uses Ribbon and distributes requests across instances of the CurrencyExchangeService.

The Feign framework helps us to write simpler RESTful clients.

Visibility And Monitoring

In Microservices Architectures, You would need to have complete visibility into what’s happening in your microservices.

In order to trace a request, you need to assign it a unique identifier. Spring Cloud Sleuth helps in assigning an identifier to every request. You can use a distributed tracing solution like Zipkin to trace the request across multiple components.

API Gateway

All micorservices have a few common features - security, logging, analytics, and so on. What is best place to implement these common features?

An API Gateway provides a great solution to this kind of a challenge.

The Netflix Zuul API gateway is a great solution to implement an API Gateway.

Fault Tolerance

What if a microservice is down? How do other microservices respond to it?

Hystrix helps in improving fault tolerance of your microservices.

Do check out our video on this:

image info

Summary

In this article, we had a look at the Spring Cloud project, and saw that it is an umbrella for a wide variety of projects. Each of these solves a particular problem associated with microservices. Important problems include service registration, service discovery, load distribution, event tracing, service monitoring and fault tolerance.

8 AWS Certification Courses

We are releasing courses for 3 Certifications under 3 categories - STEP BY STEP, EXAM REVIEW and PRACTICE TESTS:

  • Step by Step courses are for you if you are getting started with AWS
  • Exam Review courses help you to quickly review for the exam in a few hours
  • Practice Tests help you to test your preparation - How ready are you for the exam?

STEP BY STEP COURSES: ZERO AWS KNOWLEDGE? Start your journey now!

EXAM REVIEW COURSES: You prepare for the exam for 1-6 months. How do you remember everything you studied? Review for the exam in under 6 HOURS using this crash courses!

PRACTICE TESTS: Test yourselves for the certification exam with our practice tests

Best Selling Udemy Courses

Image
Image Image Image Image Image Image Image Image Image Image Image

Join 450,000 Learners and 30+ Amazing Courses

350,000 Learners are learning everyday with our Best Selling Courses : Spring Boot Microservices, Spring, Spring Boot, Web Services, Hibernate, Full Stack React, Full Stack Angular, Python, Spring Interview Guide, Java Interview, Java Functional Programming, AWS, Docker, Kubernetes, PCF, AWS Fargate and Azure


Do not know where to start your learning journey? Check out our amazing learning paths:
Learning Path 01 - Spring and Spring Boot Web Applications and API Developer,
Learning Path 02 - Full Stack Developer with Spring Boot, React & Angular,
Learning Path 03 - Cloud Microservices Developer with Docker and Kubernetes,
Learning Path 04 - Learn Cloud with Spring Boot, AWS, Azure and PCF and
Learning Path 05 - Learn AWS with Microservices, Docker and Kubernetes


Subscribe

FREE COURSES



Related Posts

Understanding jwt token

Let us understand the json web tokens

Single sign-on workflow

Let us understand the single sign-on workflow

Oauth2.0 - Resource Owner Password Credentials grant workflow

Let us understand the Oauth2.0 Resource Owner Password Credentials grant workflow

Oauth2.0 - Implicit grant workflow

Let us understand the Oauth2.0 implicit grant workflow

Oauth2.0 - Client Credentials grant workflow

Let us understand the Oauth2.0 client credentials grant workflow

Oauth2.0 - Authorization grant workflow

Let us understand the Oauth2.0 authorization grant workflow

Writing Integration Tests for Rest Services with Spring Boot

Setting up a basic REST Service with Spring Boot is a cake walk. We will go one step further and add great integration tests!

Integrating Spring Boot and Spring JDBC with H2 and Starter JDBC

Learn using Spring Boot Starter JDBC to connect Spring Boot to H2 (in memory database) using Spring JDBC. You will create a simple project with Spring Boot. You will add code to the project to connect to a database using Spring JDBC. You will learn to implement the basic CRUD methods.

JUnit Tutorial for Beginners in 5 Steps

JUnit Tutorial for Beginners in 5 Steps. Setting up a basic JUnit example and understanding the basics of junit.

JPA and Hibernate Tutorial For Beginners - 10 Steps with Spring Boot and H2

JPA and Hibernate in 10 Steps with H2 - Setting up a basic project example with Spring Boot and in memory database H2. Its a cake walk.


Search