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With any normal Azure Queue, I pop a message, then do some work. I didn't want to delete the message until after the work is done.

How long does that message stay hidden before it's deemed a failure and is made visible again on the queue?

eg.

var message = myQueue.GetMessage();

 // Do Work ..

myQueue.DeleteMessage();

My work could take .. 30 secs or something. or what happens if it took .. 1 min or 2?

I basically don't want the message to be come available again before the work is complete, incase another worker pops it off the queue .. even though this worker is still doing work.

Can we set the 'hide' time?

Pure.Krome
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2 Answers2

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Can we set the 'hide' time?

Yes. You can set the time for which a message will be hidden to other callers. If you look at the REST API documentation for Get Messages, it expects a parameter called visibilitytimeout. This parameter is responsible for hiding the message for specified number of seconds. After that time period has elapsed, the message becomes visible again if not deleted.

How long does that message stay hidden before it's deemed a failure and is made visible again on the queue?

If you're using .Net Storage Client library, you have an option to specify the visibility timeout period. Take a look at the documentation for Get Message where you can specify the visibility timeout. Since this is an optional parameter in the library (but required at the REST API level), default value provided by the library is 90 seconds.

Gaurav Mantri
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    What happens if visibility timeout has expired, message is again visible and I try to delete that message because my work took more time than visibility timeout period? – Ashutosh Singh Sep 06 '15 at 10:17
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    When you dequeue a message (using Get Message), you get a `popreceipt` that you use to delete the message. This `popreceipt` remains valid till the time message is dequeued again. So as long as your message is not dequeued, you can delete the message even if the visibility timeout period has expired. Please read Remarks section here: https://msdn.microsoft.com/en-us/library/azure/dd179347.aspx. HTH. – Gaurav Mantri Sep 06 '15 at 10:29
  • Based on your explanation, will INvisibility timeout(when invisibility expired) be more appropriate name? – Michael Freidgeim May 16 '19 at 13:25
  • Get Message link is broken. Should it be https://learn.microsoft.com/en-us/dotnet/api/microsoft.azure.storage.queue.cloudqueue.getmessage?view=azure-dotnet ? Also where 90 sec visibility timeout default value came from? according to https://learn.microsoft.com/en-us/rest/api/storageservices/Get-Messages visibilitytimeout default value is 30 seconds. – Michael Freidgeim Aug 06 '19 at 03:45
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You can specific a Visibility Timeout as a parameter to one of the GetMessage() overloads. You can also use UpdateMessage() to extend the invisibility of the message. However, you can never guarantee that the message will not be processed twice - e.g., the consumer dies having completed the work but before deleting the message. Windows Azure Queues is a best-effort FIFO queue - with at-least once semantics.

Neil Mackenzie
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  • Is there a way to make the messages visible again, before that visibility timeout period has expired? Lets say I accidentally set the timeout to 3 days and want to look at the messages after just a couple of hours? – Martin Nilsson Nov 07 '16 at 21:27
  • You could use CloudQueue.UpdateMessage (https://learn.microsoft.com/en-us/dotnet/api/microsoft.windowsazure.storage.queue.cloudqueue.updatemessage?view=azure-dotnet), setting the timeout to 1 sec to make it reappear real soon. Not sure of the use case for that, though, since you have to already have the message in order to shorten the time, exposing it to others. – sscheider Oct 25 '18 at 16:04