Docker Swarm

A Docker Swarm is a container orchestration system developed to manage clusters of Docker containers.

• Context:
  • It can (typically) transform a pool of Docker hosts into a single, virtual host, simplifying container management across multiple Docker nodes.
  • It can (often) enable the seamless scaling of applications by allowing users to deploy, manage, and scale containerized applications across multiple Docker hosts.
  • It can range from small-scale applications suitable for basic orchestration to large-scale applications requiring complex management and automation.
  • It can support load balancing and high availability of services, utilizing a built-in routing mesh to distribute service requests efficiently across all nodes in the cluster.
  • It can provide robust tools for managing secrets and configurations, ensuring sensitive data like passwords or API keys are securely stored and handled within the cluster.
  • ...
• Example(s):
  • A tech company uses Docker Swarm to manage its microservices architecture, ensuring that all services are evenly distributed across the available nodes and can handle incoming traffic through automatic load balancing.
  • An online retailer implements Docker Swarm to manage a shopping cart application, using Docker Swarm's scaling capabilities to handle varying loads during sales events.
  • ...
• Counter-Example(s):
  • Docker Compose,
  • Docker Volume,
  • Apache Mesos,
  • Kubernetes,
  • gVisor.
• See: Cluster Management System, Microservices, Virtual Machine, DevOps, Open Container Initiative, Decentralized Computing System, Distributed Computer System.

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References

2024a

• (Wikipedia, 2024) ⇒ https://en.wikipedia.org/wiki/Docker_(software)#Tools Retrieved:2024-5-12.
  • QUOTE: (...)
    • (...)
    • Docker Swarm provides native clustering functionality for Docker containers, which turns a group of Docker engines into a single virtual Docker engine. In Docker 1.12 and higher, Swarm mode is integrated with Docker Engine. The docker swarm CLI utility allows users to run Swarm containers, create discovery tokens, list nodes in the cluster, and more. The docker node CLI utility allows users to run various commands to manage nodes in a swarm, for example, listing the nodes in a swarm, updating nodes, and removing nodes from the swarm. Docker manages swarms using the Raft consensus algorithm. According to Raft, for an update to be performed, the majority of Swarm nodes need to agree on the update.
    • (...)

2024b

• (ChatGPT-OpenAI, 2024) ⇒ Prompt: Summarize the concept Docker Swarm in 1- 2 paragraphs. ChatGPT (model:gpt-4-turbo-preview). Retrieved: 2024-05-12.
  • QUOTE: Docker Swarm is an orchestration tool designed to manage a cluster of Docker containers. It allows users to deploy, scale, and manage containers across multiple Docker hosts, turning them into a single, virtual Docker host. The key feature of Docker Swarm is its ability to provide high availability of applications by distributing container instances across the swarm’s nodes. This ensures that if one node fails, the containers can be automatically scheduled on other nodes, maintaining the application’s availability without user intervention.

    Swarm mode integrates natively with Docker Engine, making it straightforward to use for those already familiar with Docker commands. It offers features like container self-healing, load balancing, decentralized design, and secure communication between nodes to manage container orchestration efficiently. Users can define the desired state of their services in a declarative fashion, and Docker Swarm takes care of the deployment and scaling to meet those requirements. This simplifies the complexities associated with managing large-scale container deployments, making Docker Swarm a powerful tool for developers and sysadmins managing microservices architectures.

2024c

• (Srivastav, 2024) ⇒ Ayushmaan Srivastav (2024). "A Comprehensive Guide to Docker Swarm: Deploying and Scaling Containers on AWS". In: Medium.com.

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