Microservices Architectures - Non Functional Requirements - Availability


In this article, we explore an important non functional requirement called Availability.

What you will learn

  • What Is Availability?
  • Why is Availability important?
  • How can you build more available systems?

Free Courses - Learn in 10 Steps

Non Functional Requirements and Microservices

This is the part of a series of articles on Non Functional Requirements:

What Is Availability?

Conceptually, availability is easy to understand. Suppose you wanted to access a website but you found that it is down. That is an indication of low availability of the website.

Availability is a measure of how frequently your system provides the desired functionality, to your users.

Typically, you want a 99.9999% or 100% availability for your system. Actually, this might not be true.

Depending on the category of an application, there might be different needs for its availability. If it is an internal application to be used within an enterprise, then it might not be needed beyond office hours.

For most system that are available over the internet, the availability needs are quite high.

Improving Availability

Consider the following system with a microservices architecture:

image info

How would you go about improving the availability of this system?

Modularity Improves Availability

Microservice architectures have high modularity. We don’t build such a system as a monolith. Instead, we break it down in to smaller components (technical and infrastructure), each of which provides a well defined interface.

Each of them is also independently deployable. Such applications will not be very bulky, nor will they need to access huge databases. That is a good head-start in giving the system high availability, since common bottlenecks are removed.

Redundancy Improves Availability

In the application example above, having multiple instances of each of Microservice1, Microservice2 and Microservice3 helps improve service availability to users.

Not just the microservices, redundancy at other levels is beneficial too. Having multiple instances of the Infrastructure components such as the NamingServer and APIGateway improves availability.

The key to high availability is to eliminate single points of failure. Ensure that all your infrastructure components have enough redundancy built in.

Monitoring Improves Availability

If an API Gateway goes down, you should NOT get to know of it from your users.

If Microservice1 crashes for some reason, you should know of it first through your internal automated mechanisms.

There needs to a facility for monitoring each of the microservices and components in the system.

On any instance of failure, the operations team needs to be alerted by some mechanism, for diagnosis and recovery.

Do check out our video on this:

image info


In this video, we talked about the availability of an application. Availability measures how frequently the system provides the desired service, to all the users. We took the example of a microservice architecture to describe how you can improve availability.

Best Selling Udemy Courses

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



Related Posts

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.

Spring Boot Tutorial For Beginners in 10 Steps

Introduction to Spring Boot in 10 Steps. Learn the basics of Spring Boot setting up a basic project example with Spring Boot.

Spring Framework Tutorial for Beginners - Your First 10 Steps

Learn the basics of Spring Framework setting up a very simple example.

JPA and Hibernate Tutorial using Spring Boot Data JPA

Complete journey starting from JDBC to JPA to Spring Data JPA using an example with Spring Boot Data JPA starter project. We use Hibernate as the JPA Implementation.

Creating a Web Application with Spring Boot with JSP

Setting up a basic web application with Spring Boot is a cake walk. We will create a simple web application using Spring Initializr and add JSP features to it.

What is Spring Boot Auto Configuration?

Auto Configuration is the most important feature in Spring Boot. In this tutorial, we will learn important concepts about Auto Configuration with a couple of examples.

Unit Testing Rest Services with Spring Boot and JUnit

Setting up a Basic REST Service with Spring Boot is a cake walk. We will go one step further and add great unit tests to our RESTful Service.