What causes SqlOpenConnectionTimeout?

The SQL Server is under heavy load and the connection queue is full. Network latency between the integration runtime and SQL server is too high. The SQL Server's max connections limit is reached. A network device (load balancer, proxy) is dropping or delaying TCP SYN packets intermittently. The SQL Server is in a recovery state after a restart or failover

How do I fix SqlOpenConnectionTimeout?

Increase the connection timeout in the ADF linked service (default is usually 30s — try 90s or 120s).

Medium severitydata source

Power BI Refresh Error:
SqlOpenConnectionTimeout

What does this error mean?

ADF or Fabric timed out opening a SQL Server connection. The server is reachable but too slow or overloaded to respond within the connection timeout.

Common causes

1The SQL Server is under heavy load and the connection queue is full
2Network latency between the integration runtime and SQL server is too high
3The SQL Server's max connections limit is reached
4A network device (load balancer, proxy) is dropping or delaying TCP SYN packets intermittently
5The SQL Server is in a recovery state after a restart or failover

How to fix it

1Increase the connection timeout in the ADF linked service (default is usually 30s — try 90s or 120s).

Beyond the docs

Common practitioner solutions not covered in the official documentation.

1Check SQL Server performance: CPU, active connections, and blocking queries in sys.dm_exec_requests
2If using Azure SQL, check for DTU/vCore exhaustion in the Azure portal metrics
3Move the integration runtime closer (same region) to the SQL Server to reduce network latency
4Consider running the pipeline during off-peak hours if the source SQL Server is heavily loaded

Frequently asked questions

Does this error affect multiple datasets at once?

If multiple datasets connect to the same data source, yes — all of them will fail until the source connectivity is restored.

Can this error be caused by a server migration or rename?

Yes — if the server name, database name, or connection string changed (e.g., during a cloud migration), Power BI still holds the old connection details. Update the connection in Power BI Desktop and republish.

Does this error appear in Power BI Desktop?

Sometimes — if you open the .pbix file and attempt a refresh, Desktop will surface the same connection error. This is useful for debugging without affecting the Service dataset.

Will the error resolve automatically once the source is back online?

Only if it was a temporary outage. The next scheduled refresh will succeed automatically. If the connection string changed or credentials expired, manual intervention is needed.

Source · learn.microsoft.com/en-us/fabric/data-factory/connector-troubleshoot-synapse-sql