دانلود کتاب ساخت میکروسرویس‌های رویدادمحور با بهره‌گیری از داده‌های سازمانی در مقیاس بزرگ

Microservices and microservice-style architectures have been around for many years, in many different forms, under many different names. Service-oriented architectures (SOAs) are often composed of multiple microservices synchronously communicating directly with one another. Message-passing architectures use consumable events to asynchronously communicate with one another. Event-driven architecture is certainly not new, but the need for handling big data sets, at scale and in real time, is new and necessitates a change from the old architectural styles. First, a point of clarity. Synchronous communication means the requesting service waits for a response to its request. It will typically block waiting for a reply, doing no other work until it receives a response. Asynchronous communication means that the requester will continue doing other work without waiting for a response. While there are a variety of ways to implement asynchronous communications, for the purposes of this book we’re going to be focused primarily on using events via event streams. After all, this is a book on event-driven microservices. In a modern event-driven microservices architecture, systems communicate asynchronously by issuing and consuming events. These events aren’t destroyed upon consumption as in a message-passing architecture (more on this in Chapter 2) but instead remain readily available for other consumers to read as they require. This distinction is important, as it allows for the truly powerful patterns covered in this book. Microservices are small and purpose-built to fulfill the business requirements of the organization. While the definition of small can vary, the service should fit (conceptually) within one’s own head, and should focus on solving specific business problems. The team that owns the microservice should be a relatively small team, or one that takes no more than two pizzas to feed, as popularized by Amazon’s adoption of microservice architectures.