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

IBM mainframes

To start with, we think it’s important to understand a little about the underlying hardware. The physical hardware instance, which is sometimes called a Central Electronics Complex (CEC), can have one or more compute engines, such as the general-purpose (GP) zIIP or IFL, and each compute engine can run one or more operating systems. Additionally, each CEC can be coupled to another CEC to provide a tightly coupled scale-out environment, as illustrated here:

Figure 2.1 – Typical mainframe configuration

Figure 2.1 – Typical mainframe configuration

This is what a typical mainframe configuration looks like.

z/OS – The most common IBM mainframe operating system

When most people think of mainframes, they are thinking of z/OS running on a GP processor on Z-series hardware. This is the operating system commonly used by banks, insurance companies, large retailers, and government agencies. The first step toward modernizing a z/OS system to Azure is to understand a little...