Refreshes from SQL over the Gateway taking longer and longer

Hi motoray 

You're observing a significant increase in data refresh durations for Power BI reports published to your Premium Capacity environment—on average, about 200 seconds longer now compared to the same time last year. Despite efforts to balance the refresh load and avoid concurrency bottlenecks, performance hasn't improved much. Most of your reports pull data from an on-prem SQL datamart via a two-node Power BI gateway cluster, which adds a layer of complexity to troubleshooting. The most notable increase in refresh times occurred between September and November 2024, indicating a possible correlation with either a change in the Power BI service, gateway updates, or infrastructure changes in your data source environment. This kind of performance degradation could be due to several factors, including changes in Power BI’s internal refresh engine behavior (especially with Premium Gen2 optimization rollouts), increased dataset complexity, SQL server performance issues, gateway load contention, or even subtle changes like Windows patches or network latency that affect the gateway-to-database connection. It’s also possible that refresh performance telemetry or capacity metrics during peak times could reveal memory or CPU constraints on your Premium node or gateway machines. To investigate further, you might analyze metrics from the Power BI Premium Metrics App, Gateway Performance Monitoring logs, and refresh logs in the Service to identify bottlenecks. Solutions others have used include scaling gateway hardware, updating gateway software, isolating high-demand refreshes to separate time windows, or migrating the gateway closer to the database for lower latency. This is a common concern for Premium users with growing usage and complex on-prem data pipelines, and pinpointing the root cause usually involves coordinated monitoring across Power BI, the gateway, and the SQL datamart.