Tag: servicebus

Azure, Azure Integration Services

Azure Logic Apps & Service Bus: When Do You Need the ‘Manage’ Claim?

Manjunath

Ever wondered why your Azure Logic Apps sometimes fail to process messages consistently from a Service Bus queue? If you’ve run into issues with scaling, missing permissions, or unexpected failures, you’re not alone.

One of the key reasons for these inconsistencies is whether runtime scaling is enabled or disabled. And a major factor that affects this is the ‘Manage’ claim in your Service Bus connection string.

Understanding the Role of Runtime Scaling

Azure Functions that process messages from Service Bus queues can scale dynamically based on queue length. This is controlled by runtime scale monitoring. Whether you need the ‘Manage’ claim depends on whether this setting is enabled or not.

When Runtime Scaling is Enabled – ‘Manage’ Claim is Required

  • When runtime scaling is ON, Azure needs to check the active message count to decide whether to scale up.
  • To get this information, the system queries the Service Bus queue metadata.
  • Without the Manage claim in the connection string, the system cannot access queue details and fails to determine the active message count.

And that’s when you start seeing errors like this:

“Connection string does not have ‘Manage Claim’ for queue ‘[Queue_Name_Here]‘. Unable to determine active message count.”

Since it can’t retrieve the queue length, it falls back on alternative metrics:

“Failed to get queue description to derive queue length metrics. Falling back to using first message enqueued time.”

When Runtime Scaling is Disabled – ‘Manage’ Claim is NOT Required

  • When runtime scaling is OFF, Azure Functions do not need to query the queue length.
  • The function still processes messages as they arrive, but without automatic scaling.
  • Since it doesn’t check queue metadata, the Manage claim is not needed.

This is why, in some cases, disabling runtime scaling makes things appear to work more reliably. There’s no interference from scaling decisions, and messages just get processed at a steady rate.

How to Avoid Failures and Keep Things Running Smoothly

If You Want Scaling (Runtime Scaling ON)

  • ✅ Make sure your Service Bus connection string has the Manage permission.
  • ✅ Enable runtime scale monitoring in Azure Function settings.
  • ✅ Keep an eye on scaling behavior in Application Insights to avoid thread pool starvation.

If You Don’t Need Scaling (Runtime Scaling OFF)

  • ✅ No need for the ‘Manage’ claim—just Listen and Send permissions are enough.
  • ✅ Adjust function concurrency settings to control the processing rate manually.
  • ✅ Monitor your Service Bus queue to ensure messages don’t pile up.

By understanding how runtime scaling and permissions interact, you can avoid frustrating failures and keep your Azure Logic Apps running smoothly. Whether you need scaling or just steady processing, configuring things the right way makes all the difference.