Saga

Status: 🟡 Starter note

Problem

A business transaction spans multiple independently owned services or databases.

Core idea

Break the workflow into local transactions and define compensating actions for failures.

Styles

• Choreography
• Orchestration

Example

Order
  |
  v
Reserve Inventory
  |
  v
Authorize Payment
  |
  v
Create Shipment

If payment fails:

Payment failed
      |
      v
Release Inventory
      |
      v
Cancel Order

Architecture questions

1. What does compensation actually guarantee?
2. When is orchestration preferable?
3. How do retries interact with compensation?
4. How do you observe a long-running Saga?