Book Image

Practical Microservices with Dapr and .NET

By : Davide Bedin
Book Image

Practical Microservices with Dapr and .NET

By: Davide Bedin

Overview of this book

Over the last decade, there has been a huge shift from heavily coded monolithic applications to finer, self-contained microservices. Dapr is a new, open source project by Microsoft that provides proven techniques and best practices for developing modern applications. It offers platform-agnostic features for running your applications on public cloud, on-premises, and even on edge devices. This book will help you get to grips with microservice architectures and how to manage application complexities with Dapr in no time. You'll understand how Dapr offers ease of implementation while allowing you to work with multiple languages and platforms. You'll also understand how Dapr's runtime, services, building blocks, and software development kits (SDKs) help you to simplify the creation of resilient and portable microservices. Dapr provides an event-driven runtime that supports the essential features you need to build microservices, including service invocation, state management, and publish/subscribe messaging. You'll explore all of those in addition to various other advanced features with this practical guide to learning Dapr. By the end of this book, you'll be able to write microservices easily using your choice of language or framework by implementing industry best practices to solve problems related to distributed systems.
Table of Contents (16 chapters)
1
Section 1: Introduction to Dapr
4
Section 2: Building Microservices with Dapr
10
Section 3: Deploying and Scaling Dapr Solutions

Autoscaling with KEDA

So far, we've learned that the HPA is triggered by the CPU and memory metrics of the Pods in a deployment.

Kubernetes-based Event-Driven Autoscaling (KEDA) is a Cloud-Native Computing Foundation (CNCF) project, with the objective of extending the capabilities of the Kubernetes HPA so that it reacts to the metrics of resources that are external to the Kubernetes cluster.

You can learn more about KEDA (https://keda.sh/) in the context of Dapr at https://docs.dapr.io/developing-applications/integrations/autoscale-keda/.

Considering the vast adoption of the publish/subscribe Dapr building block in our example, it would be smart to increase (and decrease) the number of Pods based on the messages accumulating in the underlying messaging system, which is Azure Service Bus in our case. If the number of enqueued messages grows, we could add more Pods so that Dapr dequeues the messages and our ASP.NET Core code processes the requests.

In more general terms...