Book Image

Modernizing Legacy Applications to Microsoft Azure

By : Steve Read, Larry Mead
Book Image

Modernizing Legacy Applications to Microsoft Azure

By: Steve Read, Larry Mead

Overview of this book

Organizations have varying circumstances, objectives, and prerequisites when contemplating a hyper-scale cloud solution transformation to a platform such as Azure. Modernizing Legacy Applications to Microsoft Azure uncovers potential scenarios and provides choices, methodologies, techniques, and prospective possibilities for transitioning from legacy applications to the Microsoft Azure environment. You’ll start by understanding the legacy systems and the main concerns regarding migration. Then, you’ll investigate why distributed architectures are compelling and the various components of the Azure platform needed during migration. After that, you’ll explore the approaches to modernizing legacy applications and the Rs of modernizing (i.e., rehost, refactor, rearchitect, and retire). You’ll also learn about integration approaches and potential pitfalls. By the end of this book, you’ll be well equipped to modernize your legacy workloads while being aware of pitfalls and best practices.
Table of Contents (18 chapters)
1
Part 1: Legacy Estate Options
3
Chapter 2: Strategies for Modernizing IBM and Unisys Mainframes
6
Part 2: Architecture Options
10
Part 3: Azure Deployment and Future Considerations

Exploring Deployment Options in Azure

When it comes to legacy workload deployment options, they were pretty specific to the platform you were using at the time. This is especially true for mainframes where there was a well-defined and accepted way to deploy applications. There was not a lot of variety in transaction managers, filesystems, queueing architectures, and databases. You used what was on the machine platform, and whichever tool you decided to use, it usually did a very good job at whatever it was supposed to do. A good example of this is Customer Information Control System (CICS) on IBM mainframes. If you were writing online applications on a mainframe, this is what you used to communicate with the database (typically Db2) and the user (typically a 3270 terminal). IBM midrange systems were very similar. Legacy Unix systems did allow more variability but, for the most part, had a specific set of vendor solutions that did a specific job for your application.

In the world...