Book Image

Java EE 8 Design Patterns and Best Practices

By : Rhuan Rocha, Joao Carlos Purificação
Book Image

Java EE 8 Design Patterns and Best Practices

By: Rhuan Rocha, Joao Carlos Purificação

Overview of this book

Patterns are essential design tools for Java developers. Java EE Design Patterns and Best Practices helps developers attain better code quality and progress to higher levels of architectural creativity by examining the purpose of each available pattern and demonstrating its implementation with various code examples. This book will take you through a number of patterns and their Java EE-specific implementations. In the beginning, you will learn the foundation for, and importance of, design patterns in Java EE, and then will move on to implement various patterns on the presentation tier, business tier, and integration tier. Further, you will explore the patterns involved in Aspect-Oriented Programming (AOP) and take a closer look at reactive patterns. Moving on, you will be introduced to modern architectural patterns involved in composing microservices and cloud-native applications. You will get acquainted with security patterns and operational patterns involved in scaling and monitoring, along with some patterns involved in deployment. By the end of the book, you will be able to efficiently address common problems faced when developing applications and will be comfortable working on scalable and maintainable projects of any size.
Table of Contents (20 chapters)
Title Page
Copyright and Credits
Dedication
Packt Upsell
Contributors
Preface
5
Aspect-Oriented Programming and Design Patterns
Index

Explaining the concept of canary deployment


As previously mentioned, when we write a new version of an application, we need to deliver it without stopping or delaying the service in any way. An important step, therefore, is to deploy and test the new version first. If an error occurs, we will then need to rollback the deployments and maintain the old version of the application until any problems with the new version are solved. The canary deployment was created to so solve deployment-related problems such as this.

The canary deployment is a deployment pattern that allows us to deliver a new version of an application to the subset of a server. Then, the new version of the application can be tested, and, if an error occurs, then the delivery rolls back and keeps the old version, propagating a new version for the remaining servers. In this pattern, we can define some servers as canary servers. The deployment first occurs in the canary server, after which a test is done on the canary server....