Function App under at least a Premium plan could have unlimited execution time. However, it might caused a duplicated invocation issue with a ServiceBus trigger because the "PeekLock" duration is up to 5 minutes (including renew).
It is a tutorial to reproduce such the scenario.
STEP 1: In Azure portal, create a new Premium python Function App and a Service Bus + Queue
STEP 2: Download the sample code and apply some changes.
https://cchlab.blob.core.windows.net/cchlab/cchlabsbf.zip
In "host.json", please specify the Function App timeout and the ServiceBus PeekLock timeout as below.
In "ServiceBusQueueTrigger1/function.json", please setup some configuration:
SBQ_STRING=<your service bus queue name>
Then, deploy the project to Function App.
STEP 3: Making an experiment with a short execution time.
Visit: https://<YourAppName>.azurewebsites.net/api/httptrigger1?t=<DurationInSecond>
Please specify the "DurationInSecond" to 30 this time, and you may see the result like this:
We apply this operation to send a message to the ServiceBus queue and told the ServiceBus trigger to pause 30 seconds before execution.
Now, please go to the monitor page:
You can see it is just a normal short invocation.
STEP 4: Making an experiment with a long execution time.
Visit: https://<YourAppName>.azurewebsites.net/api/httptrigger1?t=<DurationInSecond>
Please specify the "DurationInSecond" to 330 this time, and you may see the result like this:
Now, please go to the monitor page:
As you can see, there are duplicate invocations with the same message id, which might caused some potential business issues if we ignore them.
Conclusion:
Since we cannot adjust "maxAutoRenewDuration" to more than 5 minutes, we could only reduce the execution time from this ServiceBus trigger.
Microsoft
