When multiple systems exchange events, each system needs to agree on the structure and data types of event bodies. Without a shared contract, producers and consumers interpret event data differently, leading to integration failures and silent data corruption.
A schema in EventBridge serves as this contract. It is a versioned specification that defines what data an event body contains, how that data is organized, and what types each field uses. With schemas in place, producers and consumers across heterogeneous systems exchange event data reliably without ambiguity.
Schema groups
Schemas are organized into schema groups. Each schema belongs to exactly one group, and its schema ID must be unique within that group.
EventBridge provides two types of schema groups:
| Schema group type | Description |
|---|---|
| Schema group for Alibaba Cloud service events | Contains schemas for events emitted by Alibaba Cloud services. Each event type has a dedicated schema. For example, the snapshot deletion event type from Elastic Compute Service (ECS) has its own schema that describes the structure of its event body. |
| Custom schema group | A group that you create and manage to organize schemas for custom application events or existing message data. Use custom schema groups when your workloads produce events outside of Alibaba Cloud services. |