Forum Discussion
Open Mirroring Stops Working
I'm excited about the promise of Open Mirroring so far it seems to be the best and cheapest (in capacity usage) solution to lift our on-prem SQL Server data to Fabric. However, I've come across a Major Issue that seems to be a bug.
When I setup the Mirrored Database in the Fabric Workspace all my testing works on the day the Database is created. The python script that reads the SQL Server CDC logs and writes the parquet files to the Mirrored Database Landing Zone works great and changes are reflected fairly quickly and smoothly.
BUT, when I attempt to execute this script the next day... the parquet files get written to the landing zone but the Mirrored Database does not process the changes into the Delta Tables and therefore the SQL Analytics Endpoing, also any additional attempts to make changes such as deleting files from the Mirrored Database through the Landing Zone do not get reflected in the database tables or the mirroring status pages in Fabric. Effectively the Database is frozen and does not respond to anything. The only thing I can do is delete it and create a new Mirrored Database.
The naming conventions and required files are all in the structure required from the documentation no additional files are being stored in the Landing Zone. I am adding another directory under the lakehouse Files location to store the CDC LSN's used for the last run, could this be an issue? But then why does it work on day 1 and not on day 2.
Hi, russellprice9
Please refer to the following suggestions.
- Check for Naming Conventions and File Structures: Verify that the naming conventions and file structures are consistent with the documentation. Any deviation might cause issues with the mirroring process.
- Monitor the Replication Status: Use the monitoring tools available in Fabric to check the status of the replication. This can help identify if there are any errors or issues during the replication process. Monitoring in Fabric Data Warehouse overview - Microsoft Fabric | Microsoft Learn
- Investigate the Landing Zone Directory: Since you mentioned adding another directory under the lakehouse Files location to store the CDC LSN's, ensure that this does not interfere with the mirroring process. It might be worth testing without this additional directory to see if the issue persists.
Check the following link for troubleshooting.
Troubleshoot Fabric Mirrored Databases From Azure SQL Database - Microsoft Fabric | Microsoft Learn
Best Regards,
Community Support Team _Charlotte
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.
1 Reply
Hi, russellprice9
Please refer to the following suggestions.
- Check for Naming Conventions and File Structures: Verify that the naming conventions and file structures are consistent with the documentation. Any deviation might cause issues with the mirroring process.
- Monitor the Replication Status: Use the monitoring tools available in Fabric to check the status of the replication. This can help identify if there are any errors or issues during the replication process. Monitoring in Fabric Data Warehouse overview - Microsoft Fabric | Microsoft Learn
- Investigate the Landing Zone Directory: Since you mentioned adding another directory under the lakehouse Files location to store the CDC LSN's, ensure that this does not interfere with the mirroring process. It might be worth testing without this additional directory to see if the issue persists.
Check the following link for troubleshooting.
Troubleshoot Fabric Mirrored Databases From Azure SQL Database - Microsoft Fabric | Microsoft Learn
Best Regards,
Community Support Team _Charlotte
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.