How to peek dead letter queues from Azure Service Bus using Data Factory External Call transformation

Question

I have an Azure Data Factory Data Flow. I am trying to use the External Call GET to peek the Dead Letter queue items. I have authorised the Data Factory as an "Azure Service Bus Data Owner" in the role assignments of the Service bus. I have setup the linked service in Data Factory so that I can pass in the Service Bus queue name URL and this works OK for other transformations.
I have set the Relative URL to the following setting in the External call:

concat($QueueName,"/$DeadLetterQueue/messages/head")

Currently I have it with the settings as following:

However I keep getting the error "Failed to fetch data preview due to operation timeout." This makes little sense to me, I definitely have access to the Service Bus, though I expect I am doing something else wrong. Can we not use the GET part of the External Call yet??

Answer 1

Hello @Brent Leslie , Thanks for the question and using MS Q&A platform. If you try the below dynamic expression does that help ?

concat($QueueName,"/",$DeadLetter,"Queue/messages/head")

Thanks
Himanshu

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