Change Data Capture (CDC)

2 min readAug 10, 2024

Understanding CDC Benefits in Event-Driven Architecture

Change Data Capture (CDC) is a technique for monitoring and capturing data changes, allowing other systems to react or stay updated in real-time.
CDC transitions workflows from a polling-based, interval-driven model to a more efficient push-based, real-time model.
By leveraging CDC, businesses can promptly update data warehouses, brokers, and caches, enhancing the system’s responsiveness.
Tools like Debezium and Solace are utilized to facilitate CDC, allowing changes captured from databases like MySQL to be published as events.

“CDC is gaining popularity, particularly in event-driven architecture.”

One challenge with CDC in a large system is deciding whether to distribute data within the same logical boundary or to other system parts.
Direct database queries by services are discouraged to prevent tight coupling between services and architectural components.

CDC should avoid exposing internal data structure or schema; instead, it should translate state changes into meaningful business events.
Meaningful business events serve as contracts between services, allowing them to be versioned separately and maintain a clean architectural structure.

“Do not leak internal schema information in an event; do the translation.”

When employing CDC, it’s crucial to translate state changes into events that reflect business concepts rather than CRUD operations.
Translating into business events ensures that what is communicated across the system is meaningful and understandable to various services.
Proper event translation prevents tight coupling between service implementations and their respective databases while maintaining system flexibility.

“That event is your contract, and you can version it.”