Kernels (Architecture)

Pre-requisites

• Please read Terminology

Overview

The core functionalities offered by the Kernels component are

• Kernel discovery and launching. More details in general overview and code architecture
  • Discovery. Responsible for finding Jupyter kernel specs on user's machine, connecting to remote jupyter servers and turning Python Environments into Jupyter specs.
  • Kernel launcher. Launching the selected Jupyter kernel with proper environment.
• Execution. Handling the messages between the extension and Jupyter kernel.

Below graphs is a bird view of where kernels are from, how they are launched and what's being exposed once kernels are launched and connected:

• The kernel component can list all kernels found from multiple sources. The source of kernels limits how a kernel can be launched.
  • Globally installed kernel specs are started as separate processes by default and the extension will connect to it through zeromq.
    • If zeromq is not available, then we would attempt to launch jupyter notebook|lab and connect to the kernels through Jupyter Server API.
  • Jupyter servers created outside of the extension can be connected and communicated through Jupyter Server API.
  • Lastly, Python environments can be used as "kernel" (see details)