The 12 Factor App - Best Practices In Cloud Native Applications and Microservices


Image


In order that an application be deployed in the cloud and enjoy features such as auto scaling, it first needs to be cloud native. In this article, we have a close look at the best practices for cloud native applications, popularly known as The 12 Factor App.

Best Practices with Cloud and Microservices

This is the first article in a series of six articles on best practices with cloud and microservices:

Free Courses - Learn in 10 Steps

The 12 Factor App

12 Factor App is a set of best practices that guide you to build a great cloud native application. These were framed by Heroku, based on their experiences with building cloud native applications.

Codebase - One codebase tracked in revision control, many deploys

You have the codebase in a version control system, and you extract and build it, then deploy it many times.

Dependencies - Explicitly declare and isolate dependencies

Whenever you build a software application, say in Java, you need a number of dependencies such as frameworks. You may need to manage the versions of the libraries you need to use. Explicitly declare and isolate such dependencies.

Config - Store config in the environment

There are a variety of environments where an application could execute, such as development, QA, staging and production. Applications have different configuration in each of the environments. It is recommended to seperate the configuration and store it within the environment itself.

Another option is to store the configuration information in a centralized repository.

An good example is Spring Cloud Config Server. The configuration is stored in the config server, which can then be mapped to the environment.

Backing services - Treat backing services as attached resources

Backing services refers to the other systems that an application needs to talk to, and this also includes the databases. All such services need to be considered as attached resources.

All of these need to be configurable, and it should be easy to switch from one backing service to another. This switch should be possible with just a switch in configuration.

Build, release, run - Strictly separate build and run stages

The build, release and run stages need to be strictly separated.

You need to be able to build a deployable component, such as a JAR, WAR or an EAR, that is independent of the environment. There should not be any change in this component as the deployment environment changes.

A release is a phase where we take this reusable component, and combine it with a specific configuration for a target environment.

The next phase is to take the released entity, create a container out of it, and run it in the environment.

Processes - Execute the app as one or more stateless processes

Ideally an application should be stateless.

But, in case you have state - where you store the state of an application determines how flexible it is.

If you store state in a central data store such as redis, it makes the application very flexible.

You no longer need sticky sessions. You can have any instance of an app, answer any request.

Port binding - Export services via port binding

You should be able to deploy applications as services, by tying them with ports.

Concurrency - Scale out via the process model

There are two kinds of scaling that can be applied to an application - horizontal and vertical. Vertical scaling refers to increasing the hardware infrastructure, such as increasing the CPU processing power, or increasing the amount of physical memory available to the application. Clearly, there are limits to such an approach.

Horizontal scaling refers to the possibility of dynamically increasing or decreasing the number of instances of an application, depending on the system needs.

Your applications should be built to be able to dynamically adapt to changing number of instances of various services.

Disposability - Maximize robustness with fast startup and graceful shutdown

If one of the instances of the application is causing errors, or is slow in responding to requests, or is not responding at all, it should be possible to gracefully shut the instance down.

In addition, the other applications in the system should not be affected by this change in the environment.

You should be able to bring in new instances as they are needed, and take down instances when required. This property is known as disposability, and is a measure of the system’s robustness.

Development / Production Parity

There is a strong need to keep the development, QA, staging and production stages of a deployment pipeline, as similar as possible. The similarities should apply to the processes you follow, the technologies you make use of, and the infrastructure you employ.

If you have this parity among these stages, then most of the problems that could arise with the application, would appear in the earlier stages. Not many surprises would be in store for you at production.

Logs - Treat logs as event streams

Visibility is one of the most important requirements of a microservices architecture.

By treating each log message entered into a centralized logging system as an event, you get a sequence of actions that are performed on a request when it enters the system, right up to when it is completed or abandoned.

All one needs to do in order to debug a problem, is to go to the central dashboard and search for it.

Admin processes - Run admin/management tasks as one-off processes

There are a number of one-off process that you need to run - batch programs, database migrations, scripts.

Treat one-off processes the same way as long running processes.

Have the same standards - have code base in version control, follow standard deployment processes and use the same environments

Do check out our video on the same topic:

image info

Summary

In this article, we looked at the best practices for cloud native applications, called the 12 Factor App.

Best Selling Udemy Courses

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

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.


Search