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

Working with graphs

Streams are ultimately graphs. Stages can be seen as graph nodes with a certain number of input and output ports, and streams define how these nodes are connected. Akka Streams brings a GraphDSL to design your streams in a more intuitive way. This GraphDSL can be used for multiple purposes:

  • Design and compose complicated stages that would act as unique stages. These stages will also be reusable.
  • Design runnable graphs.

A runnable graph is a type of stream where there is at least one Source and one Sink and all the ports of all the stages are connected. There are built-in stages available to combine different streams. The most common junction stages are as follows:

  • Merge: This is a stage with n input ports and one output port. It merges all the incoming elements from the input with the output.
  • Balance: This is a stage with one input port and n output port. It distributes incoming elements to output ports based on demand.
  • Broadcast: This is a stage with one input port and n output...