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

The infrastructure architecture

Our application is a traditional Java application that runs on Tomcat. It uses MySQL to store the relational data and Redis to store the user sessions. As this is an enterprise application, security, availability, and scalability are all important factors. For this reason, we have placed the data tier into a separate subnet protected by a firewall; likewise, the presentation and application tiers are placed in another subnet, also protected by a firewall. The firewalls are configured so that only the Tomcat servers can connect to the data servers, and only HTTP(S) traffic from the internet is allowed into the Tomcat servers. Finally, a load balancer has been placed in front of the Tomcat servers to support our scalability and availability needs.

The following diagram captures the overall architecture of the infrastructure that houses the legacy application being introduced:

Figure 8.1 – Legacy infrastructure architecture...