Book Image

Akka Cookbook

By : Piyush Mishra, Vivek Mishra, Héctor Veiga Ortiz
Book Image

Akka Cookbook

By: Piyush Mishra, 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
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Creating a dynamically resizable pool of actors


There are situations when we want a variable number of actors under the router to handle the increasing and decreasing number of requests. The following is a recipe for such situations:

Getting ready

To step through this recipe, we need to import the Hello-Akka project. All prerequisites are the same as before.

How to do it...

  1. Create a Scala file, ResizablePool.scala, in the package com.packt.chapter3.

 

  1. Add the following import to the top of the file:
        import akka.actor.{Props, Actor, ActorSystem} 
        import akka.routing.{RoundRobinPool, DefaultResizer} 
  1. Create a case object as the message to be sent to the actor:
        case object Load 
  1. Define a dummy actor as follows:
        class LoadActor extends Actor { 
          def receive = { 
            case Load => println("Handing loads of requests") 
          } 
        } 
  1. Create a test application as follows:
        object ResizablePool extends App {  
          val system = ActorSystem...