Azure iothub can't triggering multiple Azure functions

0
votes

I have azure-iot-hub Spectraqual-free.azure-devices.net triggering a function-app https://spectralqual.azurewebsites.net -consumption plan- as event hub triggers its functions, and have bindings with azure-table-storage https://spectralqualstorage.table.core.windows.net/ The problem is that the functions not work smoothly, something goes wrong, from the functions log I can see that some of my functions triggered but didn't receive eventhubmessage and accordingly not updating the bind table storage, others not triggered at all after it was triggered successfully before,

I developed those functions first with Visual studio code, after debugging and make sure it's free of error, I pushed them to the cloud using github sync, functions that was working -triggered- before on visual studio code, I can't make it triggered again on VScode, and I'm sure that iot-hub is receiving my messages, so the messages are delivered but no trigger happen, any help please!

1
node.jsazureazure-functionsazure-iot-hub
Do you have multiple functions in the app, listening to the same event hub? – Mikhail Shilkov
yes I have multiple event hub trigger based functions and one timer trigger based function – Ayman
Do you specify distinct value for consumerGroup property for each function? – Mikhail Shilkov
No, all of consumerGroup value for all functions is $Default – Ayman

1 Answers

1
votes

If multiple Functions are bound to the same Event Hub, and you want each Function to process all events of that Hub, you have to put each Function to a dedicated Consumer Group.

Otherwise, Functions will compete for events, and the one which locks a given partition at a given time will be the only Function to get events from that partition.

Read more about Consumer Groups in docs. Use consumerGroup property of the binding to set its value for each Function.