Technology · Ebook

Drasi: Change-Driven Data Processing

by Shriira Press

Drasi, a project from Microsoft's Azure Incubations team now in the CNCF Sandbox, rethinks how software reacts to change. It replaces the brittle tangle of polling loops, change-feed consumers, and timer services with three composable pieces: Sources that tap the change feeds of databases and systems you already run, Continuous Queries written in Cypher that maintain a perpetually accurate answer to a standing question, and Reactions that fire the moment that answer changes. This book begins with the problem of change-driven systems, then walks through Sources, the property-graph model, the incremental query engine, and Reactions, before exploring Drasi's signature ability to react to the absence of change and how to deploy and operate it in production.

Contents

1. 1Preface
2. 2Chapter 1 — The Trouble with Reacting to Change
3. 3Chapter 2 — The Drasi Model
4. 4Chapter 3 — Sources: Tapping the Change Feed
5. 5Chapter 4 — The Property Graph in the Middle
6. 6Chapter 5 — Continuous Queries
7. 7Chapter 6 — Reactions
8. 8Chapter 7 — Reacting to the Absence of Change
9. 9Chapter 8 — Deploying and Operating Drasi
10. 10Chapter 9 — Drasi in Practice