Book Image

The Definitive Guide to Modernizing Applications on Google Cloud

By : Steve (Satish) Sangapu, Dheeraj Panyam, Jason Marston
Book Image

The Definitive Guide to Modernizing Applications on Google Cloud

By: Steve (Satish) Sangapu, Dheeraj Panyam, Jason Marston

Overview of this book

Legacy applications, which comprise 75–80% of all enterprise applications, often end up being stuck in data centers. Modernizing these applications to make them cloud-native enables them to scale in a cloud environment without taking months or years to start seeing the benefits. This book will help software developers and solutions architects to modernize their applications on Google Cloud and transform them into cloud-native applications. This book helps you to build on your existing knowledge of enterprise application development and takes you on a journey through the six Rs: rehosting, replatforming, rearchitecting, repurchasing, retiring, and retaining. You'll learn how to modernize a legacy enterprise application on Google Cloud and build on existing assets and skills effectively. Taking an iterative and incremental approach to modernization, the book introduces the main services in Google Cloud in an easy-to-understand way that can be applied immediately to an application. By the end of this Google Cloud book, you'll have learned how to modernize a legacy enterprise application by exploring various interim architectures and tooling to develop a cloud-native microservices-based application.
Table of Contents (26 chapters)
1
Section 1: Cloud-Native Application Development and App Modernization in Google Cloud
5
Section 2: Selecting the Right Google Cloud Services
10
Section 3: Rehosting and Replatforming the Application
17
Section 4: Refactoring the Application on Cloud-Native/PaaS and Serverless in Google Cloud

The Strangler Pattern revisited

We looked at the Strangler Pattern in Chapter 12, Designing the Interim Architecture. In that chapter, we looked at the different stages in the refactoring journey of using the Strangler Pattern. The following diagram shows the start of our journey:

Figure 13.7 – Monolithic application

In the preceding diagram, we have the initial state with no Strangler Facade in play. The entire application is in our banking-mvc project, which is deployed as a JAR or WAR file.

The following diagram shows the first steps of refactoring toward microservices by breaking out the frontend from the backend:

Figure 13.8 – Initial Strangler stage

In the preceding diagram, we have our frontend, which is our front-end project that holds all the static content for our web application. These are the stylesheets, JavaScript, HTML, and images needed for the user interface. We also have our backend, which is our banking...