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

Designing for scalability and availability

Our starting point will be the initial infrastructure architecture illustrated in the following screenshot:

Figure 10.1 – Initial infrastructure architecture

In order to address scalability and availability, we will need to make use of both a managed instance group and an HTTP(S) load balancer.

A managed instance group is a collection of identical virtual machines that are managed as a single entity, and which enables the following:

  • Autoscaling (horizontal)
  • Auto healing:
    • VM-based
    • Application-based
  • Automatic updating
  • Regional (as opposed to zonal) deployment
  • Load balancing (in conjunction with HTTP(S) load balancers)

A regional managed instance group allows us to spread our virtual machines across more than one zone in a region. This protects us from the failure of a single zone. If we deployed all our virtual machines in a single zone and that zone failed, then our entire application...