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)

Message brokers

There are multiple frameworks/vendors in the market that can be used as a message broker. You could choose enterprise JMS (http://docs.oracle.com/javaee/6/tutorial/doc/bncdq.html), specification-based message brokers such as ActiveMQ, or open source alternatives such as RabbitMQ (https://www.rabbitmq.com/).

Each broker service follows different semantics and excels in different scenarios, and you may wish to go through them in detail before deciding on one. Usually, the factors that matter are as follows:

  • PAAS versus SAAS: With PAAS (Platform as a service), you would need a solution such as Amazon SQS (https://aws.amazon.com/sqs/) where AWS would manage the broker infrastructure.
    With SAAS, you would need to manage it yourself.
  • Replication and fault tolerance: Depending on your need, you may wish to scale your broker to multiple instances so that even if one of...