MULTIJSON data format missing when creating a Data Explorer data connection in the Azure Portal

Question

When creating a data connection from ADX/Kusto to EventHub, I would like to choose the MULTIJSON data format. If I recall correctly, this option was available in the Azure Portal, but there is only the JSON format now (see screenshot).

The docs still mention that data format, and I couldn't find any mention of it being deprecated. It is still possible to set it with Terraform, and I confirmed that it is working (we had data ingestion failures with JSON that stopped when we switched to MULTIJSON).

Is the MULTIJSON data format being phased out? Is this is a bug in the Azure Portal?

Ref:
https://registry.terraform.io/providers/hashicorp/azurerm/latest/docs/resources/kusto_eventhub_data_connection#data_format
https://learn.microsoft.com/en-us/azure/data-explorer/ingest-json-formats?tabs=kusto-query-language#the-json-format

Answer 1

We recently were in contact with Microsoft on this and it turns out the selection between JSON%20Files.-,JSON,-.json) (which is in fact JSONL) and MultiJson was NOT removed, but hidden behind an utterly misnamed toggle button called "ignore format errors". The product team actually agreed with us on this misnamer.
The idea is that users should not enable this button as it would require you to provide valid JSONL format, which looks like this:

   {"name": "First Object"}
   {"name": "Second Object"}

Whereas leaving it disabled allows you to provide properly formatted MultiJSON like:

   [
     {
        "name": "First Object"
     },
     {
        "name": "Second Object"
     }
   ]

Answer 2

Hello @J-C ,

welcome to this moderated Azure community forum.

Yes, I can confirm this Multi-line-JSON was part of the selection in the past:

It is missing (although still referenced in the documentation) for both EventHub and IoTHub ingestion.

It's unclear why this is not available in the portal anymore.

Luckily, it still works for you using terraform. The same goes for the SDK.

I will try to contact someone from the team to confirm this caveat.

---

If the response helped, do "Accept Answer". If it doesn't work, please let us know the progress. All community members with similar issues will benefit by doing so. Your contribution is highly appreciated.