AI-200 practice: Implement event-driven workflows by using Azure Event Grid, including filters, custom events, and retries

Question 1

A company publishes blob-upload events from Azure Storage and also needs a downstream partner system, running on a different cloud provider, to consume the same event stream using a vendor-neutral, standardized event format rather than a proprietary schema.

What should you configure?

Accepted Answer

An Event Grid subscription that delivers events using the CloudEvents v1.0 schema instead of the proprietary Event Grid event schema

Answer

An Event Grid custom topic that delivers using the Event Grid schema only, assuming that schema is universally supported across every cloud platform

Answer

A Service Bus topic replacing Event Grid, assuming Service Bus message bodies are inherently vendor-neutral across cloud providers without mapping

Answer

An Azure Function that reformats each event manually and writes it to Blob Storage for the partner to poll, without using Event Grid delivery schemas

Question 2

An Event Grid subscription occasionally fails to deliver events to an Azure Function endpoint due to transient errors. Events must be retried automatically for a bounded period, and any event that still cannot be delivered after retries are exhausted should be captured durably for later inspection rather than silently dropped.

What should you configure on the subscription?

Accepted Answer

A retry policy with max delivery attempts and event TTL, plus a dead-letter destination such as a Storage container for events that still fail after retries

Answer

A shorter event time-to-live with no dead-letter destination, assuming Event Grid retries forever until the endpoint accepts delivery

Answer

A Service Bus-style native dead-letter queue on the Event Grid topic itself, because Event Grid topics expose the same DLQ as Service Bus

Answer

Retries disabled on the subscription, plus a health probe against the Function endpoint before every delivery attempt to avoid failures

Question 3

You use an Event Grid-triggered function to react to blob creation events and need to filter for only .pdf files above a certain size, minimizing unnecessary invocations:
```json
{
  "type": "Microsoft.EventGrid/eventSubscriptions",
  "properties": {
    "destination": {
      "endpointType": "AzureFunction",
      "properties": {
        "resourceId": "/subscriptions/.../functions/ProcessBlob"
      }
    },
    "filter": {
      "subjectBeginsWith": "/blobServices/default/containers/uploads/",
      "subjectEndsWith": ".pdf"
    }
  }
}
```
```python
@app.event_grid_trigger(arg_name="event")
def process_blob(event: func.EventGridEvent):
    data = event.get_json()
    size = data.get("contentLength", 0)
    if size < 1024 * 1024:
        return # skip small files
    process_pdf(data["url"])
```
The team wants to reduce cost by never invoking the function at all for files under 1 MB, rather than invoking it and returning early. What change accomplishes this at the Event Grid subscription level?

Accepted Answer

Add an advancedFilter to the subscription's filter block matching on the event data's contentLength property with a NumberGreaterThanOrEquals operator (data.contentLength >= 1048576) — this filters events server-side at Event Grid before delivery, avoiding function invocation entirely.

Answer

This isn't possible; Event Grid subscription filters only support subject-based string filtering.

Answer

Change contentLength filtering to happen in a Logic App placed in front of the function.

Answer

Reduce maxDeliveryAttempts to 1 so undersized events aren't retried.

Question 4

Which Azure service is best suited for reacting to lightweight, discrete system events — such as a new blob being created — by triggering downstream workflows with built-in retry and filtering?

Accepted Answer

Azure Event Grid

Answer

Azure Service Bus

Answer

Azure Data Factory

Answer

Azure Files shares

Question 5

You want an Event Grid subscription to only trigger your Azure Function for blob creation events under a specific folder path ending in '.pdf', ignoring all other blob events. What should you configure?

Accepted Answer

Subject begins/endsWith filters on the subscription

Answer

Service Bus correlation filter on a topic entity

Answer

Function app setting named FilterPath for paths

Answer

Storage lifecycle rule controlling blob tiering

Question 6

An Event Grid-triggered downstream service occasionally goes offline briefly, causing event delivery failures. You need failed events to be retried with exponential backoff and eventually captured for manual review rather than silently dropped. What should you configure?

Accepted Answer

Retry policy plus dead-letter Storage destination

Answer

Disable retries to avoid any duplicate deliveries

Answer

Fire-and-forget HTTP with no Event Grid sub

Answer

Publisher manually resends all events each day

Question 7

You need an Event Grid custom topic to publish events from a custom application (not a built-in Azure resource) whenever a new AI model version is registered. What must you create and use to publish events?

Accepted Answer

Custom topic; publish via EventGridPublisherClient

Answer

Service Bus queue named events for fan-out only

Answer

Storage queue with subscribers polling manually

Answer

App Configuration key named CustomEvents publish

Question 8

You need to configure an Event Grid subscription so failed events are ultimately stored for later analysis rather than discarded after retries are exhausted. Where should this be configured?

Accepted Answer

Dead letter destination on the event subscription

Answer

Access keys section of the Event Grid topic

Answer

CORS settings on the subscriber Function App

Answer

Diagnostic settings at the resource group scope

Question 9

You are developing an AI solution that uses Azure Event Grid to route customer feedback. You want to filter events so only those with a subject ending in .json are sent to a specific Azure Function. Which property of the Event Subscription must you configure?

Accepted Answer

subjectEndsWith

Answer

subjectBeginsWith

Answer

subjectContains

Answer

dataVersionMatch

Question 10

You are implementing an event-driven AI workflow. You want to use Azure Event Grid to handle events published from an external custom microservice. Which Event Grid resource must you create first?

Accepted Answer

Custom Topic

Answer

System Topic

Answer

Event Domain

Answer

Partner Topic

13 questions