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

Chapter 15: Handling Eventual Consistency with the Compensation Pattern

We will now turn our attention to how microservices communicate with each other and how we handle transactions when each microservice is invoked in the context of its own transaction. We will learn how to handle that issue using eventual consistency, and as a byproduct, we will also see how we can reduce the coupling between our services. We will then learn how to handle errors and do what under commitment control would have been a rollback, by using the compensation pattern. Then, we will learn how to implement what we have learned and how to set up Google Cloud Pub/Sub to support that implementation. Finally, we will deploy and test our updated application.

In this chapter, we will cover the following topics:

  • The distributed transaction problem
  • The compensation pattern
  • Creating topics and subscriptions with Google Cloud Pub/Sub
  • Implementing eventual consistency and the compensation pattern...