Overview

The Cloud is great, but it’s far away (physically). If you are a self-driving car, you can’t wait 100 milliseconds for a server in Virginia to tell you to brake. You need the answer now. Edge Computing is moving the brain from the cloud to the device (the Edge).

Core Idea

The core idea is Proximity. Speed of light is fast, but not infinite. By processing data right where it is created, you eliminate lag (latency).

Formal Definition

A distributed computing paradigm that brings computation and data storage closer to the location where it is needed, to improve response times and save bandwidth.

Intuition

  • Cloud: Sending your film to a lab to get developed. (High quality, slow).
  • Edge: Using a Polaroid camera. (Instant).

Examples

  • Self-Driving Cars: They generate 1GB of data per second. They can’t upload that to the cloud. They have a supercomputer in the trunk to process it instantly.
  • Netflix: They don’t stream movies from California. They put “Edge Servers” inside your local ISP’s building. The movie is physically only a few miles away from your house.
  • Smart Cameras: A security camera that recognizes faces on the camera itself, rather than sending the video to the cloud. This is faster and more private.

Common Misconceptions

  • It replaces the Cloud: No, they work together. The Edge does the fast, real-time stuff. The Cloud does the heavy, long-term analysis. “Fog Computing” is the layer between them.
  • 5G: The network that enables Edge Computing. It provides the high bandwidth needed to connect millions of edge devices.
  • CDN (Content Delivery Network): The original edge computing. Caching static files (images, CSS) all over the world.

Applications

  • AR/VR: If you turn your head and the virtual world lags by even 20ms, you get motion sickness. Edge computing is required to render the graphics fast enough.

Criticism / Limitations

  • Maintenance: It’s easy to manage one giant data center. It’s hard to manage 10,000 tiny servers scattered across a city.

Further Reading

  • Satyanarayanan, Mahadev. The Emergence of Edge Computing.