Build fault-tolerant, robust, and distributed applications in Scala Key Features - Understand and use the concepts of reactive programming to build distributed systems running on multiple nodes. - Learn how reactive architecture reduces complexity throughout the development process. - Get to grips with functional reactive programming and Reactive Microservices. Book Description Reactive programming is a scalable, fast way to build applications, and one that helps us write code that is concise, clear, and readable. It can be used for many purposes such as GUIs, robotics, music, and others, and is central to many concurrent systems. This book will be your guide to getting started with Reactive programming in Scala. You will begin with the fundamental concepts of Reactive programming and gradually move on to working with asynchronous data streams. You will then start building an application using Akka Actors and extend it using the Play framework. You will also learn about reactive stream specifications, event sourcing techniques, and different methods to integrate Akka Streams into the Play Framework. This book will also take you one step forward by showing you the advantages of the Lagom framework while working with reactive microservices. You will also learn to scale applications using multi-node clusters and test, secure, and deploy your microservices to the cloud. By the end of the book, you will have gained the knowledge to build robust and distributed systems with Scala and Akka. What you will learn Understand the fundamental principles of Reactive and Functional programming Develop applications utilizing features of the Akka framework Explore techniques to integrate Scala, Akka, and Play together Learn about Reactive Streams with real-time use cases Develop Reactive Web Applications with Play, Scala, Akka, and Akka Streams Develop and deploy Reactive microservices using the Lagom framework and ConductR Who this book is for This book is for Scala developers who would like to build fault-tolerant, scalable distributed systems. No knowledge of Reactive programming is required.

USE THE ACTOR MODEL TO BUILD SIMPLER SYSTEMS WITH BETTER PERFORMANCE AND SCALABILITY Enterprise software development has been much more difficult and failure-prone than it needs to be. Now, veteran software engineer and author Vaughn Vernon offers an easier and more rewarding method to succeeding with Actor model. Reactive Messaging Patterns with the Actor Model shows how the reactive enterprise approach, Actor model, Scala, and Akka can help you overcome previous limits of performance and scalability, and skillfully address even the most challenging non-functional requirements. Reflecting his own cutting-edge work, Vernon shows architects and developers how to translate the longtime promises of Actor model into practical reality. First, he introduces the tenets of reactive software, and shows how the message-driven Actor model addresses all of them–making it possible to build systems that are more responsive, resilient, and elastic. Next, he presents a practical Scala bootstrap tutorial, a thorough introduction to Akka and Akka Cluster, and a full chapter on maximizing performance and scalability with Scala and Akka. Building on this foundation, you’ll learn to apply enterprise application and integration patterns to establish message channels and endpoints; efficiently construct, route, and transform messages; and build robust systems that are simpler and far more successful. Coverage Includes How reactive architecture replaces complexity with simplicity throughout the core, middle, and edges The characteristics of actors and actor systems, and how Akka makes them more powerful Building systems that perform at scale on one or many computing nodes Establishing channel mechanisms, and choosing appropriate channels for each application and integration challenge Constructing messages to clearly convey a sender’s intent in communicating with a receiver Implementing a Process Manager for your Domain-Driven Designs Decoupling a message’s source and destination, and integrating appropriate business logic into its router Understanding the transformations a message may experience in applications and integrations Implementing persistent actors using Event Sourcing and reactive views using CQRS Find unique online training on Domain-Driven Design, Scala, Akka, and other software craftsmanship topics using the for{comprehension} website at forcomprehension.com.

Harness reactive programming to build scalable and fault-tolerant distributed systems using Scala and AkkaAbout This Book- Use the concepts of reactive programming to build distributed systems running on multiple nodes- Get to grips with the full range of Akka features including the upcoming and cutting edge experimental modules- A comprehensive coverage of the principles of FRP with real-world use cases to solve scalability issues Who This Book Is ForIf you are a developer who is passionate about building fault-tolerant, scalable distributed applications using Scala and Akka, then this book will give you a jump start. You should be familiar with Scala, but no prior knowledge of Akka and reactive programming is required.What You Will Learn- Explore functional programming using Scala- Design an asynchronous, non-blocking shopping cart application using Futures- Understand the Akka actor model and the relationship between actors and threads- Use the Actor Supervision feature to build a fault tolerant and resilient application- Create your own distributed system framework using an Akka cluster- Take a look under the hood to gain perspective on the Akka engine- See a comprehensive case study of a key value store with concurrent reads and writes- Model a finite state machine using state-driven actorsIn DetailToday's web-based applications need to scale quickly to tackle the demands of modern users. Reactive programming is the solution developed to ensure the fault tolerant and robust scaling that is essential for professional applications. Reactive programming in Scala and Akka provides a great platform to develop low latency resilient, concurrent Internet scale applications on the Java Virtual Machine.This comprehensive guide will help you get to grips with the concepts of reactive programming in order to build a robust distributed system in Scala and Akka. Written in two parts, you will first take a walkthrough of the reactive, asynchronous, and functional concepts in Scala before focusing on Akka and getting to grips with the details of real-world use cases.Begin with an introduction into functional reactive programming, before moving on to writing asynchronous application with non-blocking constructs in Scala. Get familiar with the concept of actor-based concurrency using Akka, and features such as Akka remoting, routing, and persistence capabilities to build distributed applications. Learn to scale applications using a multi-node Akka cluster and unit test Akka actors and get to grips with state machines and how to implement state-driven actors using Akka. Finally, put your skills to the test with a case study where you will concurrently and asynchronously store and retrieve data from a key value store. By progressively working through the Akka concepts, you will not only be able to write your own distributed system, but also appreciate the hidden complexity within the Akka ecosystem.Style and approachThis comprehensive guide walks you through the basics of reactive programming in Scala and Akka, explaining some of the most frequently used constructs to the most advanced features, and taking you through building a full-blown distributed system with the help of real-world examples.

Summary Reactive Web Applications teaches web developers how to benefit from the reactive application architecture and presents hands-on examples using the Play framework. Purchase of the print book includes a free eBook in PDF, Kindle, and ePub formats from Manning Publications. About the Technology Reactive applications build on top of components that communicate asynchronously as they react to user and system events. As a result, they become scalable, responsive, and fault-tolerant. Java and Scala developers can use the Play Framework and the Akka concurrency toolkit to easily implement reactive applications without building everything from scratch. About the Book Reactive Web Applications teaches web developers how to benefit from the reactive application architecture and presents hands-on examples using Play, Akka, Scala, and Reactive Streams. This book starts by laying out the fundamentals required for writing functional and asynchronous applications and quickly introduces Play as a framework to handle the plumbing of your application. The book alternates between chapters that introduce reactive ideas (asynchronous programming with futures and actors, managing distributed state with CQRS) and practical examples that show you how to build these ideas into your applications. What's Inside Reactive application architecture Basics of Play and Akka Examples in Scala Functional and asynchronous programming About Reader Description For readers comfortable programming with a higher-level language such as Java or C#, and who can read Scala code. No experience with Play or Akka needed. About the Author Manuel Bernhardt is a passionate engineer, author, and speaker. As a consultant, he guides companies through the technological and organizational transformation to distributed computing. Table of Contents PART 1 GETTING STARTED WITH REACTIVE WEB APPLICATIONS Did you say reactive? Your first reactive web application Functional programming primer Quick introduction to Play PART 2 CORE CONCEPTS Futures Actors Dealing with state Responsive user interfaces PART 3 ADVANCED TOPICS Reactive Streams Deploying reactive Play applications Testing reactive web applications

A step-by-step guide in building high-performance scalable applications with the latest features of Scala. Key FeaturesDevelop a strong foundation in functional programming and Scala's Standard Library (STL)Get a detailed coverage of Lightbend Lagom—the latest microservices framework from LightbendUnderstand the Akka framework and learn event-based Programming with Scala Book Description The second version of Scala has undergone multiple changes to support features and library implementations. Scala 2.13, with its main focus on modularizing the standard library and simplifying collections, brings with it a host of updates. Learn Scala Programming addresses both technical and architectural changes to the redesigned standard library and collections, along with covering in-depth type systems and first-level support for functions. You will discover how to leverage implicits as a primary mechanism for building type classes and look at different ways to test Scala code. You will also learn about abstract building blocks used in functional programming, giving you sufficient understanding to pick and use any existing functional programming library out there. In the concluding chapters, you will explore reactive programming by covering the Akka framework and reactive streams. By the end of this book, you will have built microservices and learned to implement them with the Scala and Lagom framework. What you will learnAcquaint yourself with the new standard library of Scala 2.13Get to grips with the Grok functional paradigmsGet familiar with type system to express domain constraintsUnderstand the actor model and different Akka librariesGrasp the concept of building microservices using Lagom frameworkDeep dive into property-based testing and its practical applicationsWho this book is for This book is for beginner to intermediate level Scala developers who would like to advance and gain knowledge of the intricacies of the Scala language, expand their functional programming tools, and explore actor-based concurrency models.

Learn how to use the Akka framework to build effective applications in Scala About This Book Covers a discussion on Lagom—the newest launched Akka framework that is built to create complex microservices easily The recipe approach of the book allows the reader to know important and independent concepts of Scala and Akka in a seamless manner Provides a comprehensive understanding of the Akka actor model and implementing it to create reactive web applications Who This Book Is For If you are a Scala developer who wants to build scalable and concurrent applications, then this book is for you. Basic knowledge of Akka will help you take advantage of this book. What You Will Learn Control an actor using the ContolAware mailbox Test a fault-tolerant application using the Akka test kit Create a parallel application using futures and agents Package and deploy Akka application inside Docker Deploy remote actors programmatically on different nodes Integrate Streams with Akka actors Install Lagom and create a Lagom project In Detail 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. Style and approach This highly practical recipe-based approach will allow you to build scalable, robust, and reactive applications using the Akka framework.

Summary Reactive Design Patterns is a clearly written guide for building message-driven distributed systems that are resilient, responsive, and elastic. In this book you'll find patterns for messaging, flow control, resource management, and concurrency, along with practical issues like test-friendly designs. All patterns include concrete examples using Scala and Akka. Foreword by Jonas Bonér. Purchase of the print book includes a free eBook in PDF, Kindle, and ePub formats from Manning Publications. About the Technology Modern web applications serve potentially vast numbers of users - and they need to keep working as servers fail and new ones come online, users overwhelm limited resources, and information is distributed globally. A Reactive application adjusts to partial failures and varying loads, remaining responsive in an ever-changing distributed environment. The secret is message-driven architecture - and design patterns to organize it. About the Book Reactive Design Patterns presents the principles, patterns, and best practices of Reactive application design. You'll learn how to keep one slow component from bogging down others with the Circuit Breaker pattern, how to shepherd a many-staged transaction to completion with the Saga pattern, how to divide datasets by Sharding, and more. You'll even see how to keep your source code readable and the system testable despite many potential interactions and points of failure. What's Inside The definitive guide to the Reactive Manifesto Patterns for flow control, delimited consistency, fault tolerance, and much more Hard-won lessons about what doesn't work Architectures that scale under tremendous load About the Reader Most examples use Scala, Java, and Akka. Readers should be familiar with distributed systems. About the Author Dr. Roland Kuhn led the Akka team at Lightbend and coauthored the Reactive Manifesto. Brian Hanafee and Jamie Allen are experienced distributed systems architects. Table of Contents PART 1 - INTRODUCTION Why Reactive? A walk-through of the Reactive Manifesto Tools of the trade PART 2 - THE PHILOSOPHY IN A NUTSHELL Message passing Location transparency Divide and conquer Principled failure handling Delimited consistency Nondeterminism by need Message flow PART 3 - PATTERNS Testing reactive applications Fault tolerance and recovery patterns Replication patterns Resource-management patterns Message flow patterns Flow control patterns State management and persistence patterns