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

The CountDownLatch pattern

Another pattern we can easily implement using Akka is CountDownLatch. The basic behavior of a latch is to wait until the count has reached zero in order to allow another action to happen. This is normally referred to as "to open the gate". The idea is to have some processing tasks running in other threads or services and wait until all of them have been completed. This pattern has multiple use cases. For example, it can be used to aggregate some elements into a single unit similarly in order to have what we implemented in the previous recipe, The aggregator pattern.

In this recipe, we will demonstrate how to create a CountDownLatch actor and use it to wait until some other processing tasks are happening in other actors. We will implement two approaches: Future and Await.

Getting ready

To step through this recipe, we need to import the Hello-Akka project; all other prerequisites are the same as earlier.

How to do it…

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