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

Understanding directives

As mentioned before, Routing DSL is basically a set of directives that you can compose to route and handle your incoming HTTP requests. Directives are small code blocks that can do things such as transform, filter, extract, or complete an incoming request.

In this recipe, we will see how to create a custom directive to measure the number of times a particular path of a route is called and also how long it took to process it. We will make use of basic directives to compose more complex ones. For this task, we will make use of Dropwizard metrics. Dropwizard metrics is a popular, stable, and simple metrics library that has an easy API to gather and report information about an application.

Getting ready

To step through this recipe, we need to import the Hello-Akka project and the required Akka HTTP dependency we added in the previous recipe. Also, we will add the Dropwizard metrics dependency to complete this recipe.

How to do it...

For this recipe, perform the following...