Docker Swarm

Docker Swarm is a container orchestration tool that allows you to cluster together groups of Docker hosts and schedule containers across them. Swarm follows the standard Docker API, so you can still use all the usual Docker commands to interact with your containers.

Swarm uses a decentralized architecture with no single point of failure. You deploy services to the cluster and Swarm handles scheduling them across the available nodes. It uses strategies like spreading containers across hosts and restarting failed containers to maintain desired state. For example, you can have a cluster of 5 hosts and deploy a service that runs 10 replicas of a container. Swarm will automatically schedule these replicas evenly across the 5 hosts. If any containers fail, Swarm will restart them on a running host. Key components of Swarm include manager nodes which maintain cluster state and worker nodes which run containers. You get built-in service discovery and load balancing between containers out of the box. Overall, Swarm simplifies container orchestration and clustering in Docker environments.