Module 17 4 lessons 67 min

Events and streams

The business wants a live count of orders per city, a full history of changes to each order, and reports that don't slow down checkout.

In this module

3 Read · 1 Lab

  1. 17.1Event sourcing and CQRSStore every change as an event instead of only the current state, and when not to.Read12 min
  2. 17.2Stream processingWindows, late events and aggregating data as it arrives.Read15 min
  3. 17.3Batch and analyticsOLTP vs OLAP, data warehouses, and running reports without slowing down orders.Read10 min
  4. 17.4Lab: Live orders per cityCount orders per city as they arrive, handling late and duplicate events, and compare the result with the nightly batch.Lab30 min
Start with 17.1 · Event sourcing and CQRS
Then · Module 18Availability and going global