Troubleshoot Fabric mirrored databases
Scenarios, resolutions, and workarounds for Microsoft Fabric mirrored databases.
Important
This feature is in preview.
Resources
Review the troubleshooting section of frequently asked questions for each data source:
- Troubleshoot Mirroring Azure SQL Database and FAQ about Mirroring Azure SQL Database
- Troubleshoot Mirroring Azure SQL Managed Instance and FAQ about Mirroring Azure SQL Managed Instance
- Troubleshoot Mirroring Azure Cosmos DB and FAQ about Mirroring Azure Cosmos DB
- Troubleshoot Mirroring Snowflake
- FAQ about Mirroring Azure Databricks
- Troubleshoot mirroring from Fabric SQL database (preview) and FAQ for Mirroring Fabric SQL database (preview)
Review limitations documentation for each data source:
- Limitations in Microsoft Fabric mirrored databases from Azure SQL Database
- Limitations in Microsoft Fabric mirrored databases from Azure SQL Managed Instance (Preview)
- Limitations in Microsoft Fabric mirrored databases from Azure Cosmos DB (Preview)
- Limitations in Microsoft Fabric mirrored databases from Azure Databricks (Preview)
- Limitations in Microsoft Fabric mirrored databases from Snowflake
- Limitations in mirroring from Fabric SQL database
Stop replication
When you select Stop replication, OneLake files remain as is, but incremental replication stops. You can restart the replication at any time by selecting Start replication. You might want to do stop/start replication when resetting the state of replication, after source database changes, or as a troubleshooting tool.
Troubleshoot
This section contains general Mirroring troubleshooting steps.
I can't connect to a source database
- Check your connection details are correct, server name, database name, username, and password.
- Check the server is not behind a firewall or private virtual network. Open the appropriate firewall ports.
No views are replicated
Currently, views are not supported. Only replicating regular tables are supported.
No tables are being replicated
- Check the monitoring status to check the status of the tables. For more information, see Monitor Fabric mirrored database replication.
- Select the Configure replication button. Check to see if the tables are present in the list of tables, or if any Alerts on each table detail are present.
Columns are missing from the destination table
- Select the Configure replication button.
- Select the Alert icon next to the table detail if any columns are not being replicated.
Some of the data in my column appears to be truncated
The Fabric warehouse does not support VARCHAR(max) it only currently supports VARCHAR(8000).
Data doesn't appear to be replicating
In the Monitoring page, the date shown is the last time data was successfully replicated.
I can't change the source database
Changing the source database is not supported. Create a new mirrored database.
Limits error messages
These common error messages have explanations and mitigations:
| Error message | Reason | Mitigation |
|---|---|---|
| "The replication is being throttled due to destination space limit." | There's a maximum of 10 TB of storage space in destination per Mirrored database. The replication is being throttled due to destination space limit. | In the source database, drop tables, remove data, or shard. |
| "The tables count may exceed the limit, there could be some tables missing." | There's a maximum of 500 tables. | In the source database, drop or filter tables. If the new table is the 500th table, no mitigation required. |
| "The replication is being throttled and expected to continue at YYYY-MM-DDTHH:MM:ss." | There's a maximum of 1 TB of change data captured per Mirrored database per day. | Wait for throttling to end. |