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

Recovering the state of an actor

Persistent actors recover the state based on their persistence ID. This ID needs to unique for a given persistent actor and within the data store. It is required to ensure the consistency of the journal when we persist events and when we recover. Each time a persistent actor is created, Akka persistence checks the journal and the snapshot stores for events and snapshots, respectively. The default behavior is to apply the latest snapshot and replay the missing events afterward. However, this behavior can be modified to our needs, as we will see in this recipe. In this recipe, we will show and explain what the different recovery strategies in Akka persistence are.

Getting ready

To step through this recipe, we need to import the hello-Akka project in the IDE; other prerequisites are the same as earlier as we have downloaded the akka-persistence dependency. For this recipe, we will use the LevelDB plugin.

How to do it…

For this recipe, we need to perform the following...