Book Image

Native Docker Clustering with Swarm

By : Fabrizio Soppelsa, Chanwit Kaewkasi
Book Image

Native Docker Clustering with Swarm

By: Fabrizio Soppelsa, Chanwit Kaewkasi

Overview of this book

Docker Swarm serves as one of the crucial components of the Docker ecosystem and offers a native solution for you to orchestrate containers. It’s turning out to be one of the preferred choices for Docker clustering thanks to its recent improvements. This book covers Swarm, Swarm Mode, and SwarmKit. It gives you a guided tour on how Swarm works and how to work with Swarm. It describes how to set up local test installations and then moves to huge distributed infrastructures. You will be shown how Swarm works internally, what’s new in Swarmkit, how to automate big Swarm deployments, and how to configure and operate a Swarm cluster on the public and private cloud. This book will teach you how to meet the challenge of deploying massive production-ready applications and a huge number of containers on Swarm. You'll also cover advanced topics that include volumes, scheduling, a Libnetwork deep dive, security, and platform scalability.
Table of Contents (18 chapters)
Native Docker Clustering with Swarm
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Dedication
Preface

Towards a decentralized discovery service


The limitation of a Swarm v1 architecture is that it uses a centralized and external discovery service. This approach makes every agent to talk to the external discovery service and the discovery service servers may see their load growing exponentially. From our experiments, for a 500-node cluster, we recommend to form an HA discovery service with at least three machines with medium-high specification, say 8 cores with 8 GB of RAM.

To properly address this problem, the discovery service used by SwarmKit and by Swarm Mode has been designed with decentralization in mind. Swarm mode uses the same discovery service codebase, Etcd, on all nodes, with no single point of failure.