Cloud Application Architecture Patterns

Chapter 9. Application Migration and Modernization

While an application can be designed new for the cloud, a Cloud Application often begins as one that runs in traditional IT and then is moved to the cloud.

So far in this book, we have assumed that when designing and architecting an application for the cloud, you are creating a new greenfield application from scratch. While greenfield development can be ideal, the reality is that many Cloud Applications start their lifecycle as traditional IT applications that are later moved to the cloud. These existing applications were designed for traditional IT and not for the cloud. As explained in Cloud Applications (Chapter 1), legacy applications often embed characteristics that work fine on traditional IT but are poorly suited for cloud computing.

This chapter explores how to move an existing application to the cloud and make it run better on the cloud. For these legacy applications to work well in the cloud, developers need to not only move the application to the cloud but often also modify the application to incorporate more of the best practices in this book.

Introduction to Application Migration and Modernization

The development effort to move an application to the cloud is often described as migration and modernization. Migration moves the application to the cloud, while modernization modifies the existing application to make it work better in the cloud.

Before we dive into patterns for moving applications to the cloud, we’ll review ...