Glossary

There are quite some new concepts and terms for beginners who want to understand more about this framework. We list them in this page

• Apache vs Nginx: the two most common open source web servers in the world.
  • The Apache HTTP server was created in 1995. It is flexible and powerful.
  • Nginx was released in 2004 as an answer to the C10K problem (handling ten thousand concurrent connections as a requirement for the modern web). It relies on an asynchronous, events-driven architecture to scale easily on minimal hardware with light-weight resource utilization.
• HAProxy is free, open source software that provides a high availability load balancer and proxy server for TCP and HTTP-based applications that spreads requests across multiple servers. It is written in C and has a reputation for being fast and efficient.
• Jekyll: Jekyll is a simple, extendable, static site generator. It accepts input text written in your favorite markup language and generate a corresponding static website. Throughout that process you can tweak how you want the site URLs to look, what data gets displayed in the layout, and more. ** GitHub Pages are powered by Jekyll: you write markdown text files. Jekyll generates a static website from them for you.
• GhubHub Pages: free web hosting service by Github, using git repo to manage content. Overlay filesystem
• Overlayfs allows one, usually read-write, directory tree to be overlaid onto another, read-only directory tree. All modifications go to the upper, writable layer. This type of mechanism is most often used for live CDs but there is a wide variety of other uses.

Docker Swarm is a clustering and scheduling tool for Docker containers.

• With Swarm, IT administrators and developers can establish and manage a cluster of Docker nodes as a single virtual system. Swarm mode also exists natively for Docker Engine, the layer between the OS and container images.
• Clustering is an important feature for container technology, because it creates a cooperative group of systems that can provide redundancy, enabling Docker Swarm failover if one or more nodes experience an outage.
• A Docker Swarm cluster also provides administrators and developers with the ability to add or subtract container iterations as computing demands change.
• Swarm mode integrates the orchestration capabilities of Docker Swarm into Docker Engine 1.12 and newer releases.
  • Swarm mode is disabled by default.
  • you can either create or join a swarm:
    • Run docker swarm init to create a single-node swarm on the current node.
    • Run docker info to check if Swarm is active or not
• more info. https://docs.docker.com/engine/swarm/swarm-mode/