Book Image

Simplifying Service Management with Consul

By : Robert E. Jackson
Book Image

Simplifying Service Management with Consul

By: Robert E. Jackson

Overview of this book

Within the elastic and dynamic nature of cloud computing, efficient and accurate service discovery provides the cornerstone for all communications. HashiCorp Consul facilitates this service discovery efficiently and securely, independent of the operating environment. This book will help you build a solid understanding of both the concepts and applications of HashiCorp Consul. You'll begin by finding out what you can do with Consul, focusing on the conceptual views of configuration samples along with Terraform code to expedite lab environment and hands-on experimentation, which will enable you to apply Consul effectively in your everyday lives. As you advance, you'll learn how to set up your own Consul cluster and agents in a single datacenter or location and understand how Consul utilizes RAFT and GOSSIP protocols for communication. You'll also explore the practical applications of primary Consul use cases, including communication flows and configuration and code examples. With that knowledge, you'll extend Consul across datacenters to discuss the applicability of multiple regions, multiple clouds, and hybrid cloud environments. By the end of this Consul book, you will have the tools needed to create and operate your own Consul cluster and be able to facilitate your service discovery and communication.
Table of Contents (12 chapters)
1
Section 1: Consul Use Cases and Architecture
6
Section 2: Use Cases Deep Dive

Protection and scale

Although Consul agents can work with services on external nodes, best practices (and best flexibility) recommend having a Consul agent co-resident on the nodes running the connected services. In many enterprises, Consul is connecting thousands of services (or more), which means Consul clusters of thousands, or tens of thousands, of nodes. Certainly, we don't want only three to five server nodes managing a cluster of that size, so let's start with expanding the Consul server cluster.

As we learned in Chapter 2, Architecture – How Does It Work?, bigger is not always better when it comes to the size of your consensus pool. We need at least three servers to obtain a quorum, but as that server count increases, it's going to take much longer for the pool to elect a leader. In order to resolve this, Consul offers the ability to configure Consul server agents as a read replica. When set with this flag, the agent doesn't participate in any...