This section provides an in-depth explanation of the architecture of the Cylc components intended for developers and system administrators.

The main Cylc 8 system components are:

Cylc Scheduler

  • The workflow engine core, Python 3 based

  • Includes the CLI (Command Line Interface)

  • And TUI, a new Terminal UI application

Cylc UI

  • In-browser web UI, includes:

  • A dashboard with summary information and documentation links

  • Integrated gscan (multi-workflow) side-panel

  • Responsive web design (from desktop to table to mobile)

  • Tabbed interface to display multiple workflow views

  • Command integration for interacting with task, jobs, and schedulers

Cylc UI Server

  • Interacts with Schedulers and the filesystem

  • Serves the UI to users

  • Can be launched by the privileged Hub, for multi-user installations

  • Or run standalone for use by a single user

  • (The UI Server is a Jupyter Server extension)

Cylc Hub

  • For proving the UI in multi-user setups.

  • Authenticates users, spawns and proxies Cylc UI Servers

  • Can run as a regular or privileged user

  • (The Hub is a Jupyterhub instance)

Network layers

  • Incremental push updates (c.f. polled full-state updates in Cylc 7)

Further Reading