Drasi: Change-Driven Data Processing
Shriira Press
A data change processing platform that detects meaningful changes across your systems and reacts the instant they happen — no polling, no glue code.
Welcome to Drasi: Change-Driven Data Processing.
Drasi, a project from Microsoft's Azure Incubations team now in the CNCF Sandbox, rethinks how software reacts to change. Most systems that need to respond to data — an order shipping, a sensor crossing a threshold, a pod going unhealthy — are built from polling loops, bespoke change-feed consumers, and queues stitched together by hand, and they grow brittle as the questions get harder. Drasi replaces all of that 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 and why it is so hard, then introduces Drasi's model and walks through each piece in turn — Sources and the property-graph view they expose, the continuous query engine and how it evaluates changes incrementally, and the Reactions that turn results into action. It then explores Drasi's most distinctive trick, reacting to the absence of change, before closing with how to deploy and operate Drasi and where it fits in a real architecture. By the end you will be able to design a change-driven solution and express it as a handful of declarative resources.
This title is part of the ShriIra library and is free to read in full, right here — our small contribution to making world-class knowledge easy to reach.
A note on reading it: open the Contents menu at the top of the reader to jump between chapters, use the Aa menu to set a comfortable text size, theme (light, sepia, or night), and single- or two-page layout. Your place is saved automatically, so you can always pick up where you left off.
We hope it serves you well.
— Shriira Press