PolarDB-X is a distributed database service compatible with the MySQL ecosystem. It produces change logs that are fully compatible with the MySQL binlog format and provides the binlog dump protocol that is fully compatible with MySQL. These logs are called global binlogs in PolarDB-X.
Global binlogs enable change data capture (CDC): subscribe to the global binlog stream to propagate data changes to downstream systems such as real-time compute engines, data warehouses, and search indexes — without modifying your existing MySQL-compatible CDC tooling.
How it works
In a distributed database, a single transaction can generate change logs across multiple data nodes (DNs). These per-node logs are called local binlogs — they are fragmented and distributed across nodes.
The CDC log engine reads local binlogs from all DNs, then sorts, merges, and reshapes them into a unified stream. The result is a global binlog where each distributed transaction appears as a single, standalone transaction — identical in format to a MySQL binlog from a single-instance database.
This means:
Third-party CDC tools that connect to MySQL can connect to PolarDB-X without modification.
Internal node scaling is transparent: no consumer-side changes are required when nodes are added or removed.
Use cases
Subscribe to PolarDB-X global binlogs to integrate with downstream systems:
Real-time computing: Stream change events to real-time computing platforms for risk control and recommendation workloads.
Data warehousing and auditing: Replicate change data to offline big data platforms to maintain data warehouses or audit trails.
Search: Sync change events to search engines to keep search indexes up to date.
Event-driven architectures: Route change events to function compute platforms to trigger serverless workflows.
Cache refresh: Invalidate or update cache entries in response to data changes.