Chain Two Business Events

Use the output of one Business Event as the trigger for publishing a second Business Event. This creates a lightweight event chain where each step signals the next.

When to use this recipe

Use event chaining when a business process has sequential stages and each stage has independent consumers. Chaining keeps each stage loosely coupled — the first publisher does not need to know what happens next.

Architecture

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flowchart TB
    P1["<b>Publisher</b><br/>Notebook"]
    E1["<b>Business Event A</b><br/>Order.Processing.Completed"]
    ACT["<b>Activator</b><br/>Monitors Event A"]
    P2["<b>Activator</b> publishes"]
    E2["<b>Business Event B</b><br/>Order.Fulfillment.Started"]
    C1["<b>Eventhouse</b><br/>Fulfillment analytics"]
    C2["<b>Activator</b><br/>Notify warehouse"]

    P1 -->|"Publishes"| E1
    E1 --> ACT
    ACT -->|"Condition met"| P2
    P2 -->|"Publishes"| E2
    E2 --> C1
    E2 --> C2

Step 1: Publish the first event

# Notebook publishes Event A when order processing completes
event_data = {
    "order_id": "ORD-4421",
    "customer_id": "CUST-882",
    "total_amount": 340.00,
    "completed_at": "2024-11-15T14:32:00Z"
}

notebookutils.businessEvents.publish(
    "MyWorkspace",
    "OrderProcessing",
    "Order.Processing.Completed",
    event_data,
    dataVersion="v1"
)

Step 2: Configure Activator to publish Event B

Go to Real-Time Hub → Business events
Find Order.Processing.Completed and click Set alert
Configure Monitor: source = Order.Processing.Completed
Configure Condition: On each value
Configure Action: Publish a business event
Select Order.Fulfillment.Started as the target event
Map fields from Event A to Event B:

Event A field	Event B field
`order_id`	`order_id`
`customer_id`	`customer_id`
(static value)	`started_at` → current timestamp

Design considerations

Keep chains short. Each hop adds latency and a potential failure point. If you need more than 2-3 steps, consider whether an orchestration tool (Data Pipeline, Power Automate) is a better fit.

Each event should be independently meaningful. If Event B is only ever triggered by Event A and has no other consumers, evaluate whether two separate events are necessary.

Do not create circular chains. Event A triggering Event B triggering Event A will cause an infinite loop. Design chains to always move forward in the process.

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