Book Image

Practical Microservices with Dapr and .NET - Second Edition

By : Davide Bedin
Book Image

Practical Microservices with Dapr and .NET - Second Edition

By: Davide Bedin

Overview of this book

This second edition 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 simplifies development while allowing you to work with multiple languages and platforms. Following a C# sample, you'll understand how Dapr's runtime, 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 for building 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. With a focus on deploying the Dapr sample application to an Azure Kubernetes Service cluster and to the Azure Container Apps serverless platform, you’ll see how to expose the Dapr application with NGINX, YARP, and Azure API Management. By the end of this book, you'll be able to write microservices easily by implementing industry best practices to solve problems related to distributed systems.
Table of Contents (20 chapters)
1
Part 1: Introduction to Dapr
5
Part 2: Building Microservices with Dapr
11
Part 3: Deploying and Scaling Dapr Solutions

Actor concurrency, consistency, and lifetime

The Dapr actor model relies on two main components: the Dapr runtime, operating in the sidecar, and the Dapr placement service. We’ll understand each of these in the following sections.

Placement service

The placement service is responsible for keeping a map of the Dapr instances that are capable of serving actors. Considering our example, the reservationactor-service application is an example of such a service.

Once a new instance of our new reservationactor-service Dapr application starts, it informs the placement service that it is ready to serve actors of the ReservationItemActor type.

The placement service broadcasts a map – in the form of a hash table with the host’s information and the served actor types – to all the Dapr sidecars operating in the environment.

Thanks to the host’s map being constantly updated, actors are uniformly distributed over the actor service instances.

In...