Dubbo Admin Events

dubbo-admin Events

Purpose

Use this skill to modify or explain the shared EventBus contract used by discovery, engine, informers, and subscribers.

When to use

Use for EventBus interfaces, resource-kind dispatching, subscriber registration uniqueness, synchronous processing, and event dispatch error behavior.

Do not use for business logic inside a single subscriber unless EventBus semantics change.

Inputs

Required:

• EventBus behavior, interface, or dispatch problem.
• Event producer or subscriber involved.

Optional:

• Event type.
• Old and new resource objects.
• Subscriber names for the same resource kind.

If missing, inspect pkg/core/events/eventbus.go and pkg/core/events/component.go first.

Workflow

1. Read pkg/core/events/eventbus.go for Event, Emitter, Subscriber, SubscriptionManager, and EventBus interfaces.
2. Read pkg/core/events/component.go for the concrete EventBus implementation.
3. Trace producers that call events.NewResourceChangedEvent and Emitter.Send.
4. Trace consumers implementing ResourceKind, Name, and ProcessEvent.
5. Read references/eventbus-dispatch.md before changing dispatch semantics.

Output format

Return event source, resource kind, subscribers called, error behavior, changed files, and validation evidence.

Validation

• Confirm Send uses NewObj() first and OldObj() for delete-like events.
• Confirm subscriber names are unique per resource kind.
• Confirm subscriber errors are logged and do not stop later subscribers.
• Run tests or targeted reasoning for discovery and engine consumers when dispatch changes.

Edge cases

• Events with both old and new nil cannot be routed.
• Dispatch is synchronous; long subscriber work blocks the caller.
• EventBus should stay domain-neutral; put business logic in subscribers.

References

• Read references/eventbus-dispatch.md for concrete dispatch rules and failure behavior.