Lakehouse SQL Analytics Endpoint no longer connecting

[rsoltau]

Hi all,

Starting this Monday between 3 AM and 6 AM, our dataflows and Power BI reports that rely on our Fabric Lakehouse's SQL Analytics endpoint began failing with the below error. The dataflows have been running for a year plus with minimal issues.

Are there any additional steps I can try? 😭

Thanks in advance for any insights or suggestions!

Troubleshooting steps taken so far, all resulting in the same error:

- Verified the SQL endpoint connection string

- Created a new Lakehouse and tested the SQL endpoint

- Tried connecting with:

- Fabric dataflow gen 1 and gen 2

- Power BI Desktop

- Azure Data Studio

- Refreshed metadata in both the Lakehouse and its SQL endpoint

Error:

Details: "Microsoft SQL: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)"

[v-prasare · Accepted solution]

Hi  @rsoltau,

In addtion to @burakkaragoz & @nilendraFabric insights, please do refer below FAQ doc related to similar issue.

https://learn.microsoft.com/en-us/troubleshoot/sql/database-engine/connect/network-related-or-instan...

Thanks,

Prashanth Are

MS Fabric community support

[v-prasare]

May I ask if you have resolved this issue? If so, please mark the helpful reply and accept it as the solution. This will be helpful for other community members who have similar problems to solve it faster.


If we don’t hear back, we’ll go ahead and close this thread. For any further discussions or questions, please start a new thread in the Microsoft Fabric Community Forum we’ll be happy to assist.
Thank you for being part of the Microsoft Fabric Community.

[v-prasare]

Hi @rsoltau,

 As we haven’t heard back from you, we wanted to kindly follow up to check if the issue got resolved? or let us know if you need any further assistance here?

Thanks,

Prashanth Are

MS Fabric community support

[v-prasare]

Hi @rsoltau, As we haven’t heard back from you, we wanted to kindly follow up to check if the issue got resolved? or let us know if you need any further assistance here?

Thanks,

Prashanth Are

MS Fabric community support

[rsoltau · Accepted solution]

Hi Prashanth,

I'm still working through this issue. It seems to be related to our firm's firewall changes that occured that Monday. 

We're currently doing some testing on the on-prem gateway and it's network security rules. 

[v-prasare]

Hi @rsoltau,

Thanks for the confirmation that this happened due firewall rules change, i request you to update workaroud you have followed and accept as answer if you have any progress on mentioned issue that your facing to help others in the community and find answers easily.

Thanks,

Prashanth Are

MS Fabric community support

[v-prasare · Accepted solution]

Hi  @rsoltau,

In addtion to @burakkaragoz & @nilendraFabric insights, please do refer below FAQ doc related to similar issue.

https://learn.microsoft.com/en-us/troubleshoot/sql/database-engine/connect/network-related-or-instan...

Thanks,

Prashanth Are

MS Fabric community support

[burakkaragoz]

Hi @rsoltau ,

This kind of error usually points to a backend connectivity issue, especially when everything was working fine before and suddenly breaks without any config changes on your side.

A few things you might want to double-check before escalating:

• Try querying the SQL endpoint using ODBC or ADO.NET from a clean environment (like a VM or different network) to rule out local firewall or DNS issues.
• If you're using a custom DNS or proxy, make sure it's not caching an old endpoint address.
• Check if the SQL Analytics Endpoint URL resolves correctly via nslookup or ping (just to confirm DNS resolution).
• Also, try accessing the endpoint using Direct Lake mode in Power BI Desktop (if available) to see if the issue is specific to SQL connectivity.

That said, if you've already tried creating a new Lakehouse and the issue persists across tools, it's very likely a stale metadata or routing issue on the backend. In that case, yeah, best to raise a support ticket with Microsoft and include:

• Workspace name and ID
• Lakehouse name
• Timestamp of the failed attempts
• Full error message and stack trace (if available)

Hope this helps a bit while you wait for support to dig in.

If my response resolved your query, kindly mark it as the Accepted Solution to assist others. Additionally, I would be grateful for a 'Kudos' if you found my response helpful.

[nilendraFabric]

Hi @rsoltau 

seems like a backend issue with stale metadata. 

Escalate to Microsoft Support: Provide error logs and workspace details for backend diagnostics