Consider the following scenario:
- You use Microsoft SQL Server 2012 Reporting Services (SSRS 2012) or SQL Server 2014 Reporting Services (SSRS 2014).
- You create a data-driven subscription and you use a query to drive the subscription.
- The query takes longer than 30 seconds to fully execute.
This issue occurs because of a defect in SQL Server 2012. For data-driven subscriptions, any time-out specified by user is not honored by using the web UI or API calls. This will result in long-running queries timing out when you click Validate or Next in the UI, or validate by using API calls.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.