Azure Alert on Dead Letter Queue for Service Bus Queue Management

Dead letter queues can be a real pain to manage, especially when you're not aware of the issues. A dead letter queue is a special kind of queue in Azure Service Bus that holds messages that cannot be processed by the intended receiver.

To stay on top of dead letter queue issues, it's essential to set up Azure alerts. Azure alerts notify you of issues, such as messages being moved to the dead letter queue, allowing you to take corrective action.

Azure alerts can be set up to trigger on various conditions, including messages being dead-lettered. This means you can receive notifications when messages are stuck and can't be processed.

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Service Bus Queue Management is a crucial aspect of Azure Alert on Dead Letter Queue. You can manage your Service Bus Queue by accessing the Monitor Views with the Resources of the Category 'Service Bus Queue' where Remote Actions are allowed.

To edit thresholds, list dead letter messages, list active messages, list scheduled messages, queue details, purge active messages, or purge dead letter messages, you can use the menu items from the Action button on selected queue.

Here are the specific actions you can perform on a Service Bus Queue:

In the event of a dead letter queue, one answer to resolving the issue is to check the Azure portal for any errors or issues.

The Azure portal provides a detailed view of the dead letter queue, including the message that caused it to be created.

Looking at the message in the Azure portal can help identify the root cause of the issue.

The message typically includes information about the error that occurred, such as a 404 status code, which can indicate a missing resource.

This information can be used to troubleshoot the issue and resolve the dead letter queue.

By checking the Azure portal and examining the message, you can often resolve the dead letter queue without needing to involve additional tools or resources.

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To set up an Azure alert on a dead-letter queue, you'll need a timer-triggered Azure Function that scans for dead-letter queues in the Azure Service Bus Namespace.

This Azure Function should be configured to use the isolated process model for better performance and isolation, and select the appropriate trigger for your function, such as a Timer Trigger.

The function should also be configured to access the Service Bus namespace and the target queue, with the necessary permissions and connection strings added to the function app settings.

To implement the rollback logic, you'll need to identify the request type and implement the corresponding rollback logic, which might involve compensating transactions, updating database records, or sending notification messages.

Here's a step-by-step breakdown of the solution architecture:

By following this architecture, you can create a timer-triggered Azure Function that scans for dead-letter queues and triggers an alert when the item count exceeds a certain threshold, allowing you to monitor and respond to dead-letter queue issues in your Azure Service Bus Namespace.

Once everything is wired up, you should start seeing some logic app runs if there are any messages that have been placed onto the DLQ.

To verify this, check the outputs from the last two actions, which should show some results from the logic app.

All you need to do now is extend the Logic App to deliver the DLQ alert to somewhere.

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Logic App Output is a crucial step in the integration process. You can expect to see Logic App runs once everything is wired up and any messages have been placed onto the Dead Letter Queue (DLQ).

The outputs from these runs are typically visible, and you can see examples of them in action. Below is an example of the outputs from the last two actions, which should give you an idea of what to expect.

These outputs are just the beginning, and you'll need to extend the Logic App to deliver the DLQ alert to somewhere.

To set up a subscription to the Blob creation event, click on Events under the Storage account for the DLQ messages.

You'll then click on the +Event Subscription to add a new subscription. This is where the magic happens, so pay attention!

Setup the subscription Basic details with a suitable subscription name and the blob storage account resource name. Uncheck the ‘Subscribe to all event types’ and select Blob Created event.

Set the endpoint details to Web Hook and the URL of the Logic App Http trigger endpoint address. This will allow you to receive notifications when a new blob is created.

Under Filters, enable subject filtering. Add the prefix ‘/blobServices/default/containers/’ to the name of the DLQ container, which in this example is ‘dlq’.

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