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August 1, 2025Lesson Learned #533: Intermittent Azure SQL Database Connectivity and Authentication Issues
August 1, 2025We’ve been working on a service request that a customer experienced frequent failures when refreshing Power BI reports connected to an Azure SQL Database. The error message indicated a problem with acquiring connections from the data source pool, leading to unsuccessful report refreshes.
We found the following error message: A request for a connection from the data source pool could not be granted. Retrying the evaluation may solve the issue. The exception was raised by the IDbCommand interface.
Analyzing the details of the case, we found that the issue occurred regardless of whether Entra ID or SQL authentication was used, we don’t have issue at Azure SQL Database level and not login error, but, we identified a high number of simultaneous connection attempts from Power BI to Azure SQL Database.
We also reviewed the configuration of Power BI Desktop and noted that it loads multiple tables in parallel during refresh operations. This behavior triggers a surge of concurrent connections to the database, which in this scenario resulted in exhaustion of the connection pool at the application layer.
We suggested to reduce the parallel table loading setting in Power BI Desktop, using File > Options and settings > Options > Data Load and Under Parallel loading of tables. Later adjusted the setting to a higher value to find a balance between performance and stability.