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

Creating topics and subscriptions with Google Cloud Pub/Sub

We will now provision two topic and subscription pairs. The reason we have two pairs is that we will need to use the dead-letter functionality of Google Cloud Pub/Sub. The dead-letter functionality is to place a message (event) that was not acknowledged as delivered into another topic after a certain number of failed delivery attempts. This means that we are storing each event that could not be processed into that topic, which allows us to correct the problem later. The first pair is for dead letters, and the second pair is for our application to publish and subscribe to.

To create the necessary topic and subscription pairs, we will take the following steps in the cloud console:

  1. From the navigation menu, click Pub/Sub, as illustrated in the following screenshot:

    Figure 15.3 – Navigation menu: Pub/Sub

  2. On the Topics page, click CREATE TOPIC, as illustrated in the following screenshot:

    Figure 15.4 –...