Every SSRS request is treated as a task. These tasks are processed within a thread. Availability of threads (or lack thereof) will determine whether a given task is immediately processed or left in the queue for a thread to become available. Therefore, this counter measures the total number of tasks awaiting thread availability.
DBAs, Server administrators, System administrators, Web administrators, Report developers
- Consider offloading some Report Sever operations to a separate server which should reduce bottlenecks
- Try not to have all scheduled tasks kick off at the same time