Book Image

The DevOps 2.1 Toolkit: Docker Swarm

By : Viktor Farcic
Book Image

The DevOps 2.1 Toolkit: Docker Swarm

By: Viktor Farcic

Overview of this book

Viktor Farcic's latest book, The DevOps 2.1 Toolkit: Docker Swarm, takes you deeper into one of the major subjects of his international best seller, The DevOps 2.0 Toolkit, and shows you how to successfully integrate Docker Swarm into your DevOps toolset. Viktor shares with you his expert knowledge in all aspects of building, testing, deploying, and monitoring services inside Docker Swarm clusters. You'll go through all the tools required for running a cluster. You'll travel through the whole process with clusters running locally on a laptop. Once you're confident with that outcome, Viktor shows you how to translate your experience to different hosting providers like AWS, Azure, and DigitalOcean. Viktor has updated his DevOps 2.0 framework in this book to use the latest and greatest features and techniques introduced in Docker. We'll go through many practices and even more tools. While there will be a lot of theory, this is a hands-on book. You won't be able to complete it by reading it on the metro on your way to work. You'll have to read this book while in front of the computer and get your hands dirty.
Table of Contents (22 chapters)
Title Page
Credits
About the Author
www.PacktPub.com
Customer Feedback
Preface
11
Embracing Destruction: Pets versus Cattle

Load balancing requests across all instances of a service


Before we explore load balancing, we need to have something to balance. We need multiple instances of a service. Since we already explored scaling in the previous chapter, the command should not come as a surprise:

eval $(docker-machine env node-1)

docker service scale go-demo=5

Within a few moments, five instances of the go-demo service will be running:

Figure 3-5: Docker Swarm cluster with the go-demo service scaled

What should we do to make the proxy load balance requests across all instances? The answer is nothing. No action is necessary on our part. Actually, the question is wrong. The proxy will not load balance requests at all. Docker Swarm networking will. So, let us reformulate the question. What should we do to make the Docker Swarm network load balance requests across all instances? Again, the answer is nothing. No action is necessary on our part.

To understand load balancing, we might want to go back in time and discuss load...