IotHub custom endpoints, 9 of 10 used, Azure portal keeps failing to create 10th

Question

Good day,

Been trying over and over for quite some time to create the 10th custom endpoint in our IotHub, in the Azure Portal.
I keep getting an internal error and told to contact support, but don't have a support plan. We are not on the free tier but paying for our IotHub , Function Apps etc.
The docs say you are allowed 10 custom endpoints and that is a serious limitation in design, requiring multiple hacks and dependencies on Function Apps.
On the portal we have 9 active custom endpoints. Only 9 are listed.
When I try and create the 10th one, with endpoint-type: Cosmos DB , with no syntehtic partition key and key-based authentication, it fails with internal error.
I tried a few seconds ago, and this is the error message:
There was a problem updating your IoT hub to add a new endpoint. An unexpected error occurred while updating your IoT hub. Error message: Internal Error. If you contact a support representative please include this correlation identifier: eb0497fd-b4f8-4b6b-ab9f-47ed729ee3c1, timestamp: 2024-12-09 09:04:42Z, errorcode: IH500019.

Hoping somebody can help.

I have considered using an event grid, and routing to it, and then via a function app to cosmos db, but if the function app fails (and they have gone offline before) then data lost. So I don't want to use that option.
I feel I should be allowed to use my 10 endpoint.

Regards

Answer 1

Hello @Adrian Wreyford,

welcome to this moderated Azure community forum.

The Azure IoT Hub B and S tiers (except for the free tier) can have up to 10 routing endpoints.

I recommend creating a support ticket so the Azure team can check the backend.

Personally, I use the IoT Hub routing for technical routing, I try to separate types of message (telemetry, alert, heartbeats, etc.) and IoT Hub events (like connect/disconnect, device twin updates, etc.) and send them a limited set of different endpoints.

For functional routing (eg. splitting up messages per customer) the Azure Stream Analytics job is a far more flexible solution.

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