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

Disaster recovery


If the swarm directory content is lost or corrupted on a manager, it's required to immediately remove that manager out of the cluster using the docker node remove nodeID command (and use --force in case it gets stuck temporarily).

The cluster administrator should not start a manager or join it to the cluster with an out-of-date swarm directory. Joining the cluster with the out-of-date swarm directory brings the cluster to an inconsistent state, as all managers will try to synchronize wrong data during the process.

After bringing down the manager with the corrupted directory, it's necessary to delete the /var/lib/docker/swarm/raft/wal and /var/lib/docker/swarm/raft/snap directories. Only after this step can the manager safely re-join the cluster.