Azure Function with Service Bus Trigger Timeout Warnings

Question

We are working on an interface project using a combination of Azure Functions with Azure Service Busses (using Topics with sessions enabled). Everything works fine, but when I logon to the Function App's log stream in the Azure portal, I get this warning:

RunOperation encountered an exception and will retry. Exception: Azure.Messaging.ServiceBus.ServiceBusException: The operation did not complete within the allocated time 00:01:00 for object receiver2108. (ServiceTimeout)
 ---> System.TimeoutException: The operation did not complete within the allocated time 00:01:00 for object receiver2108.
   at Microsoft.Azure.Amqp.AsyncResult.End[TAsyncResult](IAsyncResult result)
   at Microsoft.Azure.Amqp.AmqpObject.OpenAsyncResult.End(IAsyncResult result)
   at Microsoft.Azure.Amqp.AmqpObject.EndOpen(IAsyncResult result)
   at Microsoft.Azure.Amqp.AmqpObject.<>c.<OpenAsync>b__51_1(IAsyncResult r)
   at System.Threading.Tasks.TaskFactory`1.FromAsyncCoreLogic(IAsyncResult iar, Func`2 endFunction, Action`1 endAction, Task`1 promise, Boolean requiresSynchronization)

However, the software works fine. All service bus messages are operated correctly and fine. The Function App's Topic triggers are all correctly configured and work fine.

I have no clue what this warning comes from.

Any ideas? Thanks in advance.

Answer 1

If you're not seeing interruptions to your message processing, this is safe to ignore and should be considered normal behavior.

This error indicates that the Service Bus client used by the trigger was unable to establish either a connection or link to the service. Generally, these are transient and caused by the inherent unreliability of networks. The client will continue to retry forever, and will recover when network connectivity is restored.

If you're not seeing noticeable interruptions to your message processing, you can consider these benign. If you are seeing an impact to throughput or messages not flowing consistently, it may indicate a problem that you'll need to resolve.

Ensuring that your Service Bus namespace and Function app are running in the same region would be a good idea. If they are, then you may want to open an Azure support request and ask for investigation into the network stability for your Function app.