Book Image

Scala Microservices

By : Selvam Palanimalai, Jatin Puri
Book Image

Scala Microservices

By: Selvam Palanimalai, Jatin Puri

Overview of this book

<p>In this book we will learn what it takes to build great applications using Microservices, the pitfalls associated with such a design and the techniques to avoid them. </p><p>We learn to build highly performant applications using Play Framework. You will understand the importance of writing code that is asynchronous and nonblocking and how Play leverages this paradigm for higher throughput. The book introduces Reactive Manifesto and uses Lagom Framework to implement the suggested paradigms. Lagom teaches us to: build applications that are scalable and resilient to failures, and solves problems faced with microservices like service gateway, service discovery, communication and so on. Message Passing is used as a means to achieve resilience and CQRS with Event Sourcing helps us in modelling data for highly interactive applications. </p><p>The book also shares effective development processes for large teams by using good version control workflow, continuous integration and deployment strategies. We introduce Docker containers and Kubernetes orchestrator. Finally, we look at end to end deployment of a set of scala microservices in kubernetes with load balancing, service discovery and rolling deployments. </p><p></p>
Table of Contents (12 chapters)

The feedback loop

We went over what might be some of the key principles for an effective development process in the last section. In this section, we will try to enumerate and visualize this development process and call it the feedback loop. The objective is to provide guidelines and industry-best practices to enable you to define your own feedback loop eventually. Every team is unique, but all good engineering teams have a great amount of overlap.

If you think about it, we can model (almost) every good process into a closed loop system, be it an architectural design, a job interview, or a government health care plan. A closed loop system feeds back part of the output signal into the input as an error signal. In case the output is drifting away from the expected output, the error signal will help modulate the input to reduce the difference. The following image shows a closed loop...