Docker Swarm Orchestration

Orchestrating containers with Docker Swarm allows you to manage a Docker host cluster as a single virtual Docker host.

Docker Swarm is a native container orchestration solution from Docker, enabling you to control a Docker host cluster as one unified virtual Docker host. Swarm provides built-in features for service discovery, load balancing, rolling updates and failover, making it a simple solution for container orchestration without added complexity.

Manager: Node that manages the cluster

Worker: Node that executes containers

Service: Definitions of tasks for containers

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Docker Compose for Swarm

Swarm automatically provides load balancing through internal DNS:

Frequently Asked Questions (FAQ)

Frequently asked questions

For HA: should we use multiple manager nodes?

For HA: use multiple manager nodes (an odd number), deploy managers in different availability zones, use multiple replicas for services, configure health checks, use restart policies, monitor node health, and set up automatic failover. Swarm automatically moves tasks from failed nodes to healthy nodes. It’s crucial to have sufficient resources on the nodes to handle failures.

For monitoring: should we use docker s?

For monitoring: use `docker service ls` and `docker node ls` for basic status, use `docker service ps` for task details, use `docker service logs` for logs, integrate with Prometheus through cAdvisor or node-exporter, use Portainer for GUI management, and configure alerts on node failures. Also monitor resource usage on the nodes.

Does Swarm support rolling updates by default?

Swarm supports rolling updates by default: use `docker service update` with `--update-parallelism` and `--update-delay`, use `--update-order start-first` for zero-downtime, configure health checks for proper readiness, and use `--update-failure-action rollback` for automatic rollback in case of problems. Rolling updates update replicas one at a time, ensuring availability.

Does Swarm have built-in secrets management?

Swarm has built-in secrets management: create secrets through `docker secret create`, secrets are stored encrypted in the Raft log, secrets are only accessible on nodes where the service is running, secrets are available as files in `/run/secrets/`, and secrets are automatically rotated upon updates. Do not store secrets in images or environment variables. Secrets are encrypted in transit and at rest.

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Everything above runs in your browser — open Force-Directed Graph and change the parameters while it is running. Nothing is installed, nothing is uploaded, the whole model lives in one tab.

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