Issue Connecting MongoDB via Cosmos DB in Microsoft Fabric: Intermittent Timeout Errors

[zas_infinity]

I'm using MongoDB as a source, connecting through Azure Cosmos DB for MongoDB. I'm facing an odd issue where I get multiple timeout errors consistently, but after several retries, the connection eventually becomes successful. Each time I run the pipeline, I encounter errors around 3-4 times, and then—almost at random—it connects successfully.

The backend timeout is set to 1200 ms, and this works perfectly fine with Azure Data Factory (ADF) and Mongo Compass. The problem only seems to arise when connecting through Microsoft Fabric.

Here's the error message:

"Type=DnsClient.DnsResponseException,Message=Query 41403 => example-cosmos-mongo-vcore.global.mongocluster.cosmos.azure.com IN TXT on 169.254.0.x:xx timed out or is a transient error.,Source=DnsClient,
Type=System.Net.Sockets.SocketException,Message=A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond,Source=DnsClient,"

Has anyone encountered a similar issue or found a workaround? Any help or suggestions would be greatly appreciated!

[zas_infinity]

Hi @Anonymous 
thankyou for you response

I tried your suggestion of increasing the time out to 10,000 and even 12,000 as well but the same probelm persists, Moreover I even have tried setting up the mongodb to higher tier but that was also of no use. 

[Anonymous]

Hi @zas_infinity 

You might need to increase the timeout appropriately to avoid frequent timeout errors. Try a greater timeout (e.g. 10,000 ms). You can adjust it based on the actual situation to achieve better reliability.

Best Regards,
Jing
Community Support Team