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Batch delete messages in Azure Service Bus (Preview)

  • Article

Azure Service Bus is a fully managed enterprise integration message broker that enables you to send and receive messages between decoupled applications and services. However, sometimes you might want to delete messages from a queue or subscription without processing them, for example, if they're expired, corrupted, or irrelevant. This article shows you how to delete messages in batches in Azure Service Bus.

Scenarios for Batch deletion of messages

There are several scenarios where you might want to use the batch delete messages feature in Azure Service Bus. Some of them are:

  • Expired Messages: Delete messages that exceed their time to live (TTL) value and are in the dead-letter queue.
  • Failed Validation or Processing: Remove messages that failed validation or processing logic and are in the dead-letter queue.
  • Irrelevant Messages: Delete messages no longer relevant for your application logic from the active queue.
  • Handling Duplicates or Incorrect Content: Remove duplicate or incorrect messages from the active queue.

By using the batch delete messages feature, you can delete multiple messages from a queue or subscription in one operation, instead of deleting them one by one. Since deletion is done at service side, you don't need to receive the messages before deleting them. This method minimizes both the number of service requests and network latency.

Important

Currently, Batch delete is not supported with partitioned entities. You can delete a maximum of 4000 messages in a batch delete call. Batch deletion is done on a best-effort basis and doesn’t guarantee the exact messageCount will be deleted in single API call.

How to batch delete messages in Service Bus

You can delete messages by calling DeleteMessagesAsync on Service Bus Receiver object. On the server side, DeleteMessagesAsync requires two parameters: messageCount and beforeEnqueueTime.

  • messageCount: The desired number of messages to delete. The service might delete fewer messages than this limit.
  • beforeEnqueueTime: An optional DateTimeOffset, in UTC, representing the cutoff time for deletion. Only messages that were enqueued before this time are deleted.

Additionally, you can call PurgeMessagesAsync to purge all messages from entity.

Using Azure portal

You can also purge messages from entity using Service Bus explorer available on Azure portal. You can follow following steps to purge messages:

  1. Navigate to 'Service Bus explorer' blade on the entity you want to delete messages from.
  2. Choose 'Receive mode' in Service Bus explorer dropdown.

Screenshot of dropdown with Receive mode selected.

  1. Click on the purge messages option as shown in snapshot.

Screenshot of Purge messages selected.

  1. Another dialog box will appear, enter 'purge' to execute purge messages operation.

Screenshot of entering Purge to confirm.

When using Azure SDKs to perform these operations, the beforeEnqueueTime parameter defaults to the current UTC time (DateTime.UtcNow()). It’s important to ensure you provide the correct values to prevent unintended message deletion.

Note

The purge operation could lead to increased CPU usage as it involves multiple API calls. During purge, locked messages are not eligible for removal and will remain in the entity.

Next steps

To explore Azure Service Bus features, try the samples in language of your choice:

Samples for the older .NET and Java client libraries:

On 30 September 2026, we'll retire the Azure Service Bus SDK libraries WindowsAzure.ServiceBus, Microsoft.Azure.ServiceBus, and com.microsoft.azure.servicebus, which don't conform to Azure SDK guidelines. We'll also end support of the SBMP protocol, so you'll no longer be able to use this protocol after 30 September 2026. Migrate to the latest Azure SDK libraries, which offer critical security updates and improved capabilities, before that date.

Although the older libraries can still be used beyond 30 September 2026, they'll no longer receive official support and updates from Microsoft. For more information, see the support retirement announcement.