Book Image

Akka Cookbook

By : Vivek Mishra, Héctor Veiga Ortiz
Book Image

Akka Cookbook

By: Vivek Mishra, Héctor Veiga Ortiz

Overview of this book

Akka is an open source toolkit that simplifies the construction of distributed and concurrent applications on the JVM. This book will teach you how to develop reactive applications in Scala using the Akka framework. This book will show you how to build concurrent, scalable, and reactive applications in Akka. You will see how to create high performance applications, extend applications, build microservices with Lagom, and more. We will explore Akka's actor model and show you how to incorporate concurrency into your applications. The book puts a special emphasis on performance improvement and how to make an application available for users. We also make a special mention of message routing and construction. By the end of this book, you will be able to create a high-performing Scala application using the Akka framework.
Table of Contents (18 chapters)
Title Page
About the Authors
About the Reviewer
Customer Feedback

Using Distributed Publish-Subscribe in the cluster

Akka clustering provides a fault-tolerant decentralized service to deploy actors. However, you need to know in advance in which node your actors are living to be able to interact with them. One module that can help us achieve this is Distributed Publish-Subscribe. This module brings the concept of a standard pub-sub pattern within our cluster.

This pattern provides a mediator actor that keeps an eventually consistent registry of actors across the cluster. This allows any actor on any node to send a message to a registered actor on any other node. Moreover, you can subscribe an actor to a topic. Once an actor publishes to that topic, all the subscribers get a copy of the message:

Getting ready

For this recipe, we will set up a cluster of nodes running on the same machine. For this, we will use two different ports specified in two different application.conf files. We will run an application that will have a notification publisher and notification...