InfraKit and Docker Swarm Mode: A Fault-Tolerant and Self-Healing Cluster

Back in October 2016, Docker released Infrakit, an open source toolkit for creating and managing declarative, self-healing infrastructure. This is the second in a two part series that dives more deeply into the internals of InfraKit.

Introduction

In the first installment of this two part series about the internals of InfraKit, we presented InfraKit’s design, architecture, and approach to high availability.  We also discussed how it can be combined with other systems to give distributed computing clusters self-healing and self-managing properties. In this installment, we present an example of leveraging Docker Engine in Swarm Mode to achieve high availability for InfraKit, which in turn enhances the Docker Swarm cluster by making it self-healing.  

Docker Swarm Mode and InfraKit

One of the key architectural features of Docker in Swarm Mode is the manager quorum powered by SwarmKit.  The manager quorum stores information about the cluster, and the consistency of information is achieved through consensus via the Raft consensus algorithm, which is also at the heart of other systems like Etcd. This guide gives an overview of the architecture of Docker Swarm Mode and how the manager quorum maintains the state of the cluster.

One aspect of the cluster state Continue reading

InfraKit Under the Hood: High Availability

Back in October, Docker released Infrakit, an open source toolkit for creating and managing declarative, self-healing infrastructure. This is the first in a two part series that dives more deeply into the internals of InfraKit.

Introduction

At Docker,  our mission to build tools of mass innovation constantly challenges to look at ways to improve the way developers and operators work. Docker Engine with integrated orchestration via Swarm mode have greatly simplified and improved efficiency in application deployment and management of microservices. Going a level deeper, we asked ourselves if we could improve the lives of operators by making tools to simplify and automate orchestration of infrastructure resources. This led us to open source InfraKit, as set of building blocks for creating self-healing and self-managing systems.

There are articles and tutorials (such as this, and this) to help you get acquainted with InfraKit. InfraKit is made up of a set of components which actively manage infrastructure resources based on a declarative specification. These active agents continuously monitor and reconcile differences between your specification and actual infrastructure state. So far, we have implemented the functionality of scaling groups to support the creation of a compute cluster or Continue reading