This means designing systems as small composable units, expressing constraints and interactions via the type system, and using composition to guide the construction of large systems in a way that maintains the original architectural vision.The book also serves as an introduction to the Cats library. We use abstractions from Cats, and we explain the structure of Cats so you can use it without fear in your own code base. The broad ideas are not specific to Cats, but Cats provides an excellent implementation that is beneficial to learn in its own right.

    Akka uses Actors-independently executing processes that communicate via message passing—as the foundation for fault-tolerant applications where individual actors can fail without crashing everything. Perfect for high-volume applications that need to scale rapidly, Akka is an efficient foundation for event-driven systems that want to scale elastically up and out on demand, both on multi-core processors and across server nodes.Akka in Action is a comprehensive tutorial on building message-oriented systems using Akka. The book takes a hands-on approach, where each new concept is followed by an example that shows you how it works, how to implement the code, and how to (unit) test it. You'll learn to test and deploy an actor system and scale it up and out, showing off Akka's fault tolerance. As you move along, you'll explore a message-oriented event-driven application in Akka. You'll also tackle key issues like how to model immutable messages and domain models, and apply patterns like Event Sourcing, and CQRS. The book concludes with practical advice on how to tune and customize a system built with Akka.

    Designed for experienced developers ready to advance their status, Exam Ref focuses on the critical-thinking and decision-making acumen needed for success at the Microsoft Specialist level.Focus on the expertise measured by these objectives:Implement and manipulate document structures and objectsImplement program flowAccess and secure dataUse CSS3 in applicationsThis Microsoft Exam Ref:Organizes its coverage by exam objectives.Features strategic, what-if scenarios to challenge you.Includes a 15% exam discount from Microsoft. (Limited time offer)

    The Reactive Application model addresses these demands through new patterns designed to "react" effectively to user and system events, changes in load, competition for shared system resources, and unanticipated failures. Although reactive design patterns can be implemented using standard enterprise development tools, you best realize the benefits when you pair them with a functional programming language like Scala and an Actor-based concurrency system like Akka.Reactive Design Patterns is a clearly-written guide for building event-driven distributed systems that are resilient, responsive, and scalable. Written by the authors of the Reactive Manifesto, this book teaches you to apply reactive design principles to the real problems of distributed application development. You'll discover technologies and paradigms that can be used to build reactive applications including Akka and other actor-based systems, functional programming, replication and distribution, and implementation techniques such as futures, iteratees, and reactive streams. While the book presents concrete examples in Scala, Java, JavaScript, and Erlang, the primary goal is to introduce patterns and best practices that you can use to apply reactive principles to common problems you'll face when building distributed systems.WHAT'S INSIDE* Discover best practices and patterns for building responsive applications* Build applications that can withstand hardware or software failure at any level* Patterns for fault tolerance, scalability, and responsiveness* Maximize multicore hardware using asynchronous and event-driven solutions* Scale applications under tremendous loadReaders should be familiar with a standard programming language like Java, C++ or C# and be comfortable with the basics of distributed systems. Software engineers and architects will learn how to avoid common pitfalls and apply patterns for solving day-to-day problems in a fault-tolerant and scalable way to maximize their application's responsiveness to users and clients. Project leaders and CTOs will gain a deeper understanding of the philosophy behind resilience and scalability in distributed systems, as well as their limitations, challenges and benefits.

    It presents a learning journey, not definitive guidance. It describes the experiences of a development team with no prior CQRS proficiency in building, deploying (to Windows Azure), and maintaining a sample real-world, complex, enterprise system to showcase various CQRS and ES concepts, challenges, and techniques.The development team did not work in isolation; we actively sought input from industry experts and from a wide group of advisors to ensure that the guidance is both detailed and practical.The CQRS pattern and event sourcing are not mere simplistic solutions to the problems associated with large-scale, distributed systems. By providing you with both a working application and written guidance, we expect you’ll be well prepared to embark on your own CQRS journey.

    By presenting the emerging best practices and designs from the Scala community, it guides you through dozens of powerful techniques example by example.About the BookScala is a powerful JVM language that blends the functional and OO programming models. You'll have no trouble getting introductions to Scala in books or online, but it's hard to find great examples and insights from experienced practitioners. You'll find them in Scala in Depth.There's little heavy-handed theory here—just dozens of crisp, practical techniques for coding in Scala. Written for readers who know Java, Scala, or another OO language.Purchase of the print book comes with an offer of a free PDF, ePub, and Kindle eBook from Manning. Also available is all code from the book.What's InsideConcise, expressive, and readable code style How to integrate Scala into your existing Java projects Scala's 2.8.0 collections API How to use actors for concurrent programming Mastering the Scala type system Scala's OO features—type member inheritance, multiple inheritance, and composition Functional concepts and patterns—immutability, applicative functors, and monads========================================​==========Table of ContentsScala—a blended language The core rules Modicum of style—coding conventions Utilizing object orientation Using implicits to write expressive code The type system Using implicits and types together Using the right collection Actors Integrating Scala with Java Patterns in functional programming

    Specifically, you’ll learn how a Reactive microservice isolates everything (including failure), acts autonomously, does one thing well, owns state exclusively, embraces asynchronous message passing, and maintains mobility.Bonér also demonstrates how Reactive microservices communicate and collaborate with other services to solve problems. Get a copy of this exclusive report and find out how to bring your enterprise system into the 21st century.Jonas Bonér is Founder and CTO of Lightbend, inventor of the Akka project, co-author of the Reactive Manifesto and a Java Champion. Learn more at: http://jonasboner.com.

    Cloud computing is rapidly transitioning from a niche technology embraced by startups and tech-forward companies to the foundation upon which enterprise systems build their future. In order to compete in today’s marketplace, organizations large and small are embracing cloud architectures and practices.

    This is necessary because, in the words of Michael Polanyi, "we can know more than we can tell." Our design choices are not the result of an ineluctable chain of logic; they come from a deeper place, one which is visceral and inarticulate.Polanyi calls this "tacit knowledge", a thing which we only understand as part of something else. When we speak, we do not focus on making sounds, we focus on our words. We understand the muscular act of speech, but would struggle to explain it.To write software, we must learn where to draw boundaries. Good software is built through effective indirection. We seem to have decided that this skill can only be learned through practice; it cannot be taught, except by example. Our decisions may improve with time, but not our ability to explain them. It's true that the study of these questions cannot yield a closed-form solution for judging software design. We can make our software simple, but we cannot do the same to its problem domain, its users, or the physical world. Our tacit knowledge of this environment will always inform our designs.This doesn't mean that we can simply ignore our design process. Polanyi tells us that tacit knowledge only suffices until we fail, and the software industry is awash with failure. Our designs may never be provably correct, but we can give voice to the intuition that shaped them. Our process may always be visceral, but it doesn't have to be inarticulate.And so this book does not offer knowledge, it offers clarity. It is aimed at readers who know Clojure, but struggle to articulate the rationale of their designs to themselves and others. Readers who use other languages, but have a passing familiarity with Clojure, may also find this book useful.

    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.

    The vision behind Clojure is of a radically simple language framework holding together a sophisticated collection of programming features. Learning Clojure involves much more than just learning the mechanics of the language. To really get Clojure you need to understand the ideas underlying this structure of framework and features. You need this book: an accessible introduction to Clojure that focuses on the ideas behind the language as well as the practical details of writing code.

    Domain modeling is a technique for creating a conceptual map of a problem space such as a business system or a scientific application, so that the developer can write the software more efficiently. The domain model doesn't present a solution to the problem, but instead describes the attributes, roles, and relationships of the entities involved, along with the constraints of the system.Reactive application design, which uses functional programming principles along with asynchronous non-blocking communication, promises to be a potent pattern for developing performant systems that are relatively easy to manage, maintain and evolve. Typically we call such models "reactive" because they are more responsive both to user requests and to system loads. But designing and implementing such models requires a different way of thinking. Because the core behaviors are implemented using pure functions, you can reason about the domain model just like mathematics, so your model becomes verifiable and robust.Functional and Reactive Domain Modeling teaches you how to think of the domain model in terms of pure functions and how to compose them to build larger abstractions. You will start with the basics of functional programming and gradually progress to the advanced concepts and patterns that you need to know to implement complex domain models. The book demonstrates how advanced FP patterns like algebraic data types, typeclass based design, and isolation of side-effects can make your model compose for readability and verifiability.On the subject of reactive modeling, the book focuses on higher order concurrency patterns like actors and futures. It uses the Akka framework as the reference implementation and demonstrates how advanced architectural patterns like event sourcing and CQRS can be put to great use in implementing scalable models. You will learn techniques that are radically different from the standard RDBMS based applications that are based on mutation of records. You'll also pick up important patterns like using asynchronous messaging for interaction based on non blocking concurrency and model persistence, which delivers the speed of in-memory processing along with suitable guarantees of reliability.

     I am an independent mobile app entrepreneur just like you, and I wrote this book to teach you all my strategies for how to: - Get 1,000,000+ downloads from mobile app store marketing - Save money by doing your own ASO (search engine optimization SEO for Android and the Apple App stores) better than most consultants you might consider hiring - Create an app marketing strategy outside the app stores by getting press coverage and learning how to promote an app using social media and social sharing - Make money with effective app store monetization to help you maximize your app revenue with subscriptions, in-app purchases, publishing effective ads, selling affiliate products and other strategies used by successful mobile app businesses - Create a successful mobile app business I wrote this book with all my heart and soul. The book draws on my own years of experience building top apps in my niche, promoting apps, making money with my apps, and coaching other app entrepreneurs on how they can make turn their mobile apps into successful businesses. You will be getting the best of all worlds. First, I have very deep hands on experience building and growing my own apps. Second, I have a wealth of experience coaching and observing other app entrepreneurs whose experiences and aspirations are probably very similar to yours. In this book you get all the insights from me making my own apps a success, and the insights of the cumulative experiences of the people I've coached. This is a very to the point book with many actionable tips and strategies for how to promote your mobile app (iPhone or Android), make money from your smartphone applications, and generally treat it as a real business. All suggestions in this book are based on my own experiences promoting my own problemio.com business apps which at the point of latest revision of this book have cumulative 1,000,000+ downloads, and insights of me having coached over 100 other app entrepreneurs. I am an independent mobile application developer and mobile application entrepreneur just like you. I am not a multi-million dollar app development studio or a big company. If you are an independent app developer just like me, you can use the mobile application marketing strategies that I outline in this book. Many of the strategies are simple and effective, and you can begin working on them as early as today. The book contains over 20 strategies to promote your apps. They all worked for my apps and they will help you grow your app to its highest potential. After growing your app, you will be able to make good money from your app, and achieve the goals that you have for your app business. Get the book now, and become a pro at app store marketing (app store SEO which is otherwise known as ASO), and start increasing your app downloads and revenue today!

    This practical guide from renowned software architect Neal Ford helps you transition from a Java-writing imperative programmer to a functional programmer, using Java, Clojure, and Scala as examples.Rather than focus on specific language features, Functional Thinking looks at a variety of common practices in OOP languages and then shows you how to solve the same problems with a functional language. For instance, you know how to achieve code-reuse in Java via mechanisms such as inheritance and polymorphism. Code reuse is also possible in functional languages, using high-order functions, composition, and multi-methods.Ford encourages you to value results over steps, so you can begin to think like a functional programmer. Expect your mind to be bent, but you’ll finish with a much better understanding of both the syntax and semantics of functional languages.

    Intended for developers who are already familiar with the Apex language, and experienced Java and C# developers who are moving to Apex, this book starts where the Force.com documentation leaves off. Instead of trying to cover all of the features of the platform, Advanced Apex programming focuses entirely on the Apex language and core design patterns. You’ll learn how to truly think in Apex – to embrace limits and bulk patterns. You’ll see how to develop architectures for efficient and reliable trigger handling, and for asynchronous operations. You’ll discover that best practices differ radically depending on whether you are building software for a specific organization or for a managed package. And you’ll find approaches for incorporating testing and diagnostic code that can dramatically improve the reliability and deployment of Apex software, and reduce your lifecycle and support costs. Based on his experience both as a consultant and as architect of a major AppExchange package, Dan Appleman focuses on the real-world problems and issues that are faced by Apex developers every day, along with the obscure problems and surprises that can sneak up on you if you are unprepared.