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

Implementing eventual consistency and the compensation pattern

In this section, we examine the code required to implement eventual consistency and compensations. Before jumping into our code, we will briefly discuss Spring Integration, which gives us a standardized way of handling enterprise integration patterns in our code, much as Spring Data gives us a standardized way of handling object-relational mapping and transactional databases. We do not need to get down to the low-level detail of the Google Pub/Sub application programming interface (API) as that is abstracted for us by Spring Integration. The major components of Spring Integration we will need to understand are listed here:

  • ChannelAdapter: A channel adapter is an interface provided by Spring that handles the low-level details of communicating with a provider. In our case, Spring Integration provides a PubSubInboundChannelAdapter component, which implements this interface to handle Google Cloud Pub/Sub and receives...