Event Grid Domain

Overview

Event Grid Domain is a tool for managing a large number of Event Grid Topics tied to the same application — similar to a meta-topic with thousands of sub-topics. Turbo360 manages three Event Grid Domain resources: Event Grid Domain itself, Event Grid Domain Subscription (which receives all events sent to the Domain, regardless of which Domain Topic they were sent to), and Event Grid Domain Topic (an auto-managed, per-customer topic within the Domain).

Business value

Managing Event Grid Domains, Subscriptions, and Topics from Turbo360 gives you a single place to recover dead-lettered events and verify multi-tenant event delivery, reducing the time to detect and resolve failures across large topic counts.

How it works

• Event Grid Domains use the same publishing architecture as Azure services like Storage and IoT Hub, enabling publishing to thousands of topics while providing per-topic authorization and authentication so tenants stay isolated. A single endpoint accepts all customer events, and Event Grid ensures each Topic only sees events relevant to its tenant.
• Domain Topics are auto-managed: an Event Subscription can be created at the Domain scope without first creating the Domain Topic, and Event Grid creates it automatically on your behalf. When the last subscription to a Domain Topic is deleted, the Domain Topic is also deleted, whether it was created manually or automatically.
• Azure Active Directory serves as the authentication and authorization layer for customers subscribing to their own Domain Topic.

Permissions

Access to Event Grid Domain actions is controlled through RBAC when adding a role to a Business Application.

Operations

Turbo360 lets you recover dead-lettered events and send test traffic directly from Event Grid Domain resources, without switching to the Azure portal.

Sending test events (Event Grid Domain)

• Inline task to send events — quickly send events to an Event Grid Domain by providing Event Data count, Event Type, Subject, Data Version, and an optional configuration name to save it. Use this when you need to verify events reach the correct Domain in a multi-Domain Business Application.

Task status can be viewed under Automated tasks -> Task history.

The Automated task feature is also useful when a Business Application contains multiple Event Grid Domains and you need to send scheduled or unscheduled events to a specific one.

Dead-letter event recovery (Event Grid Domain Subscription)

If an Event Grid Domain Subscription fails to receive events, a Dead-Lettering mechanism captures the failed events in a Storage Blob Container — unlike Service Bus Dead-Lettering, which uses its own dead-letter queue. For example, if the destination of a Domain Subscription is a Service Bus Queue and the Queue is accidentally deleted, an Azure Function listening on that Queue would never receive the events; they would instead land in the configured Blob Container.

Turbo360 provides a UI to access these failed events, helping you resolve the issue and keep track of failures.

The event content can be viewed with basic properties as well as the dead-letter reason.

Dead-letter event processing is only possible if both conditions are met:

1. The Event Grid Domain Subscription is configured with a custom Event Grid Domain Topic.
2. The Storage Account Container configured as the dead-letter destination has public anonymous access to either the container or its blobs.

• Resubmit — resubmit a dead-lettered event (single or bulk) back to the Event Grid Domain Topic, retaining all event properties (Id, Subject, Event Type, Event Time, Data Version, Metadata Version, Event Data). Use this when the endpoint that was down is now available and the event can be replayed as-is.
• Repair and resubmit — modify properties such as Event time or Subject before resubmitting. Use this when the dead-lettered event's properties need correction before replay.
• Purge — delete a dead-lettered event (single or bulk) from the configured dead-letter destination. Use this once events have been processed manually and no longer need to be retained.

Bulk operations (Event Grid Domain Subscription)

• Inline task to purge events — quickly purge all events, or a specific set within a chosen time period, directly from the Event Grid Domain Subscription section. Use this when you need to clear a backlog of dead-lettered events without configuring a recurring schedule.

Task status can be viewed under Automated Tasks -> Task history.

The Event Grid domain Subscription dead-letter processing automated task schedules dead-letter event processing to run at specified intervals.

Sending test events (Event Grid Domain Topic)

• Inline task to send events — quickly send events to an Event Grid Domain Topic by providing Event Data count, Event Type, Subject, Data Version, and an optional configuration name to save it. Use this when you need to verify that all Domain Subscriptions on a Topic correctly receive published events.

Task status can be viewed under Automated Tasks -> Task history.

The Automated Task feature is also useful when multiple Event Grid Domain Subscriptions exist for a single Domain Topic and you need to verify all of them received the published events.

Resource dashboard

Event Grid Domain

The Event Grid Domain dashboard surfaces delivery and tenant-level signals across all topics in the Domain.

Metrics

The Metrics tab surfaces domain-wide delivery rate and failure trends across all topics in the Event Grid Domain. Use the Metrics tab to identify whether delivery failures are isolated to specific tenant topics or affecting the Domain broadly, helping you scope the impact before drilling into individual subscriptions.

Event Grid Domain Subscription

The Event Grid Domain Subscription dashboard surfaces delivery and dead-letter signals so you can spot failed deliveries without leaving Turbo360.

Metrics

The Metrics tab surfaces subscription-level delivery and filtering data for Event Grid Domain Subscription, giving you visibility into per-tenant delivery health and dead-letter accumulation trends. Use the Metrics tab to confirm whether a subscription's delivery failure pattern matches a broader Domain issue or is isolated to that subscription.

Event Grid Domain Topic

The Event Grid Domain Topic dashboard surfaces publish success and failure signals at the per-customer topic level.

Metrics

The Metrics tab surfaces per-customer topic publish and delivery data for Event Grid Domain Topic, giving you visibility into individual tenant event flow. Use the Metrics tab to correlate per-topic delivery failures with changes in that tenant's publishing configuration or event schema.

You can add, remove, or reconfigure widgets on any of these dashboards to focus on the metrics most relevant to your support scenario.

Monitoring

Event Grid Domain

Tracks Domain-level metrics against a configured threshold. Use this when you need to be alerted if delivery failures across the Domain exceed expected bounds.

1. Navigate to Event Grid Domain -> Monitoring.
2. Select the necessary monitoring metrics and configure the threshold values.
3. Click Save.

The threshold values can be provided with any metric name; the rule is violated when the configured threshold is met.

Event Grid Domain Subscription

Tracks subscription-level metrics against a configured threshold. Use this when you need to be alerted if dropped or dead-lettered event counts exceed expected bounds.

1. Navigate to Event Grid Domain Subscription -> Monitoring.
2. Select the necessary monitoring metrics and configure the threshold values.
3. Click Save.

Event Grid Domain Topic

Tracks per-topic metrics against a configured threshold. Use this when you need to be alerted if publish failures for a specific customer topic exceed expected bounds.

1. Navigate to Event Grid Domain Topic -> Monitoring.
2. Select the necessary monitoring metrics and configure the threshold values.
3. Click Save.

Troubleshooting

1. Dead-lettered events are not accessible from Turbo360
   Cause: The Storage Blob Container configured as the dead-letter destination is not associated with the same Business Application as the Domain Subscription.
   Fix: Associate the Blob Container with the same Business Application as the Event Grid Domain Subscription.
2. Resubmit or Repair & Reprocess options are unavailable
   Cause: The Event Grid Domain Subscription is not configured with a custom Event Grid Domain Topic, or the dead-letter Storage Account Container lacks public anonymous access.
   Fix: Confirm both conditions are met before attempting dead-letter recovery.
3. A Domain Topic disappears unexpectedly
   Cause: The last subscription to that Domain Topic was deleted, which auto-deletes the Domain Topic.
   Fix: Recreate an Event Subscription at the Domain scope; Event Grid will auto-create the Domain Topic again if needed.
4. Not all Domain Subscriptions receive events sent to a Domain Topic
   Cause: A filter on one or more Domain Subscriptions is excluding the published event.
   Fix: Review each Domain Subscription's event filter and adjust as needed.

Related articles

• Event Grid
• What is an automated task?
• Rules configuration