Docker Swarm #

Allows running multiple Docker hosts as a single cluster.

Enables high availability and load balancing.

Requirements #

Multiple hosts with Docker installed, one host designated Swarm Manager and others as Worker (nodes).

Swarm Manager #

On the host to be the manager, run to start:

docker swarm init

This is immediately followed by a command output to be run on the worker nodes to link them to the manager. The command for the workers would be along the lines of:

docker swarm join --token <some token value>

Docker service #

To run multiple instances of containers efficiently across multiple nodes.

Run this on the manager node:

docker service create --replicas=<number of replicas across nodes> <application>