Azure Digital Twin create data history connection issue

Question

I am trying to create ADT data history connection to get ADT data to ADX on my infrastructure which is not working although I followed the documentation at all steps for the required resources and the permissions all is setup correctly, but not data is flowing to the eventhub and the ADX corresponding database tables. At the end the connection is showing as successful but with Managed identity and ADX cluster name as N/A which is weird. and no data flow is taking place between ADT -> EventHubs -> ADX Please find the below documentation I am following https://learn.microsoft.com/en-us/azure/digital-twins/how-to-create-data-history-connection?tabs=cli All resources and permissions are set in the proper way, managed identities also are enabled and managed in the proper way but always having the data connection in this way.

Appreciate you guidance, I opened an issue on MS side and they referred to this forum Issue: https://github.com/MicrosoftDocs/azure-docs/issues/118967

Answer 1

Hi @Islam Mohammed I have tested the tutorial steps and could confirm that steps outlined in setting up the connection do work as intended and I could see the data flowing to the ADX database.

As indicated in your Data History connection image, Authentication type in my case displayed as System Identity during the Data History connection creation. However, once the connection is established, the Authentication change to N/A That being said, I could see my ADX cluster details correctly. Please find the below image for reference.

I understand you may have given multiple tries at this and validated the permissions already. I appreciate if you can revalidate the below permissions and confirm they are set as expected.

1. Navigate to your Event Hubs instance and click on Access Control (IAM) on the portal. View Role assignments and confirm if your Digital Twin instance is assigned access. Please refer the below image.

1. Navigate to Azure Data Explorer cluster and click on Access Control (IAM) on the portal. View Role assignments and confirm if your Digital Twin instance is assigned access. Please refer the below image.

No data an Event Hub end point

If you are not receiving the data at the Event Hub end point even after validating the permissions, it could be possible that your $Default consumer group could be used by another end point. Please try creating a standard Event Hub instance and assign a unique consumer group to the Event hub instance. Use that consumer group name while establishing the Data History Connection.

After you start the Simulation on ADT it may take a few minutes before you could see the data on ADX cluster. Please make sure your change the batching frequency to ingest data every 10 seconds by running the below command on your database.

.alter table AdtPropertyEvents policy ingestionbatching @'{"MaximumBatchingTimeSpan":"00:00:10", "MaximumNumberOfItems": 500, "MaximumRawDataSizeMB": 1024}'

Here is the result I see on my end point with the simulated data

Please let us know if you need further assistance on this issue after reviewing the above steps. We would be glad to connect with you offline and help you address this issue.

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