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)

Deployment topology

In this section, we will look at the deployment strategy of our Talent Search engine app. This step is required before we proceed to write kubernetes configuration files. Since the configuration will be based on the topology.

Our focus is on running the application in with high availability and fault tolerance. What it means is that the application should always try to respond to adverse conditions such as machine failure, excessive traffic, spikes in traffic, network failure on machine, and so on.

This is also a good time to analyze the requirements and define Service Level Agreement (SLA) for each service to better allocate resources. It's impossible to predict all of it right away, but we need to start somewhere. Also, kubernetes has built-in auto scaling (https://kubernetes.io/docs/tasks/run-application/horizontal-pod-autoscale/) to handle unprecedented...