Issue while trying to use an on-premises SQL Server source in Microsoft Fabric pipeline

[Rakuka]

Hi Fabric team,

Good morning

I am facing an issue while trying to use an on-premises SQL Server source in Microsoft Fabric through an on-premises data gateway.

Environment

Fabric trial capacity
Source: local/on-prem SQL Server hosted on my laptop
SQL Server test connection in SSMS works successfully using localhost,1433
Database: OBT
Gateway name: OneBridge
Authentication used in Fabric connection: Basic (sa)
What I configured

Created an on-premises SQL Server connection in Manage Connections and Gateways
Connection name: OBT_SQL_Local_1433_OneBridge
Server: localhost,1433
Database: OBT
Gateway cluster: OneBridge
Observed behavior

The gateway OneBridge is visible and online under On-premises data gateways
Gateway network diagnostics passed successfully, including Fabric-related endpoint checks
The SQL Server connection row gets created and shows Gateway cluster name = OneBridge
However, the connection does not become properly usable:
it remains non-clickable / not fully online
it does not appear correctly in Copy activity source selection
Copy activity shows no usable results for the saved connection
In earlier attempts, I also saw an error similar to:
undefined not found in linked-service-registry
Troubleshooting already completed

Verified SQL Server connectivity in SSMS using localhost,1433
Verified target database OBT is accessible
Recreated the connection multiple times
Deleted faulty/old test connections
Tested across different workspaces
Tested in different browser sessions
Verified gateway is online
Ran gateway diagnostics and network port tests successfully
Expected behavior
The saved on-prem SQL Server connection should become fully usable and appear in Fabric Copy activity / pipeline source selection.

Actual behavior
The connection is only partially created and cannot be used in pipeline Copy activity.

Please investigate whether this is a Fabric connection registration, linked service registry, or gateway integration issue on the service side.

I can provide screenshots of:

Manage Connections and Gateways
Gateway online status
Gateway diagnostics results
SSMS successful connection using localhost,1433
Copy activity source picker not showing the saved connection.
Thank you in advance
Rakuka

[tayloramy]

Hi @Rakuka, 

If you open the gateway software and perform the network ports test, what is the result? 

[Rakuka]

Hi @tayloramy,
Yes, I opened the on-premises data gateway software and ran the Network ports test.
The result was 34/34 tests succeeded. The test also showed success for the Fabric-related endpoint ci.frontend.clouddatahub.net on port 443, and all listed gateway/service bus endpoints were returned as Open/Success. So based on the gateway diagnostics, there does not appear to be a firewall, outbound port, or general gateway network communication issue.
Despite that, the SQL Server connection in Fabric still does not become fully usable in Copy activity.

[Lodha_Jaydeep]

Hi @Rakuka,

Thanks for reaching to community, will happy to assist. Localhost on the gateway configuration would not be work I think. Below is the reasons and fixes you can try.

Root Cause

localhost doesn't work with the on-premises data gateway. The gateway runs as a Windows service under a different identity and cannot resolve localhost the same way SSMS does on your machine. This is why the connection appears created and online but never becomes fully usable.

Fix - Replace localhost with Machine Name (Do This First)

Instead of localhost,1433 use your actual machine hostname:

1. Find your machine name:

   Run → cmd → type: hostname

1. In Manage Connections and Gateways, delete the current OBT_SQL_Local_1433_OneBridge connection
2. Recreate it with:
   • Server:  YOUR-PC-NAME,1433 or YOUR-PC-NAME\INSTANCENAME
   • Database: OBT
   • Gateway: OneBridge
   • Authentication: Basic (sa)\Any if you create new.

Probably this will fix your issue. Please have a look at the below screenshots for the same.

Note: New connection with the machine name should be tested with the SSMS first if you are able to connect. Also, as you are able to create gteway connection so, I am assuming that Remote/TCP connections are allowed for your SQL server.

[Lodha_Jaydeep]

Hi @Rakuka,

Thanks for reaching to community, will happy to assist. Localhost on the gateway configuration would not be work I think. Below is the reasons and fixes you can try.

Root Cause

localhost doesn't work with the on-premises data gateway. The gateway runs as a Windows service under a different identity and cannot resolve localhost the same way SSMS does on your machine. This is why the connection appears created and online but never becomes fully usable.

Fix - Replace localhost with Machine Name (Do This First)

Instead of localhost,1433 use your actual machine hostname:

1. Find your machine name:

   Run → cmd → type: hostname

1. In Manage Connections and Gateways, delete the current OBT_SQL_Local_1433_OneBridge connection
2. Recreate it with:
   • Server:  YOUR-PC-NAME,1433 or YOUR-PC-NAME\INSTANCENAME
   • Database: OBT
   • Gateway: OneBridge
   • Authentication: Basic (sa)\Any if you create new.

Probably this will fix your issue. Please have a look at the below screenshots for the same.

Note: New connection with the machine name should be tested with the SSMS first if you are able to connect. Also, as you are able to create gteway connection so, I am assuming that Remote/TCP connections are allowed for your SQL server.

[Rakuka]

Hi Jaydeep,

Thank you for your suggestion.

We had already tested these paths during troubleshooting. Port 1433 is confirmed to be working, and SQL Server is successfully reachable from SSMS using the same machine where the gateway is installed. We also tested multiple server name variations, including localhost,1433, host/machine-name based formats, and named-instance style formats.

In addition, we verified that the OneBridge gateway is online, the gateway network diagnostics completed successfully (34/34 tests passed), and the Fabric SQL connection is bound to the gateway cluster. We also tested in different workspaces and browsers, deleted and recreated the faulty connections, and re-created a clean on-prem SQL Server connection several times.

Despite all of this, the connection still does not become fully usable inside Fabric Copy activity, and we also encountered the errors like error 26 and “undefined not found in linked-service-registry.” Because of that, this now appears to be beyond a basic hostname, port, or TCP configuration issue.

I also doubted that because Fabric trial version is having some inherent features' non-availability. 

But when I tried your solution I got error 26 saying "Fabric cannot locate the specified SQL Server instance or database" in source section of the pipeline's copy activity.

Regards

~~~~~~~~~~~~~~~~~~~~

Rakuka

[Lodha_Jaydeep]

Hi @Rakuka,

Thanks for getting back to me. I’m also using a Free Trial capacity, and the configuration shown in my screenshots is working as expected.

Before we try the new Server/Machine name in Fabric again, could you confirm if you can successfully connect using that same name within SSMS? This helps us rule out any local connectivity issues.

Regarding the error message 'undefined not found in linked-service-registry,' this actually appears to be a Fabric backend service registration failure rather than a misconfiguration on your end or a network issue.

Since you’ve already attempted to re-configure the gateway multiple times without success, we might want to try a different authentication approach.

could you test using Windows Authentication with your specific username to see if that bypasses the registry error? Be make sure to not skip connection you can get the window Auth user name from the SSMS and password should be used for the log-on to the machine.

I’m happy to keep digging into this with you. If this helps resolve the issue, please consider marking this as the Accepted Solution so it can help other community members. Kudos are always appreciated!

[Rakuka]

Thank you for the follow-up, @Lodha_Jaydeep

Yes, we already completed that validation. Connectivity was tested from SSMS on the same machine where the gateway is installed, and port 1433 is working. Multiple server-name formats were also tested during troubleshooting, including localhost,1433, machine-name based formats, and named-instance style formats. In addition, the OneBridge gateway is online and the gateway Network ports test completed successfully (34/34 passed).

We also agree that the undefined not found in linked-service-registry message looks more like a Fabric backend/service registration issue than a local SQL Server, gateway, or firewall issue. That is consistent with the fact that the problem persists even after repeated reconfiguration, connection recreation, workspace changes, and browser changes.

Windows Authentication was also attempted earlier, in addition to SQL authentication, and neither path made the connection fully usable inside Fabric Copy activity. Based on the full set of checks completed so far, this now appears to be beyond a basic connectivity or authentication configuration issue.