CQRS and Event Sourcing

CQRS and Event Sourcing#

CQRS (Command Query Responsibility Segregation) and event sourcing are frequently discussed together but are independent patterns. You can use either one without the other. Understanding each separately is essential before combining them.

CQRS: Separate Read and Write Models#

Most applications use the same data model for reads and writes. The same orders table serves the API that creates orders and the API that lists them. This works until read and write requirements diverge significantly.

Temporal Workflow Example: Container Lifecycle Management with Docker

Container Lifecycle Workflow#

This article builds a complete Temporal workflow that manages Docker container lifecycle operations: inspect a container, stop it if running, create a snapshot (commit), and handle failures by restarting the container. It demonstrates every pattern from Multi-Stage Temporal Workflows in a concrete, runnable example.

The full source is in the companion repo under container-lifecycle/.

The Use Case#

You need to automate container maintenance: take a snapshot of a running container for backup or migration purposes. The sequence is: