1. A method for grouping and dispatching scans in a cache directory of a processing environment, comprising: aggregating a plurality of scan tasks from a scan wait queue into a scan task queue, the plurality of scan tasks determined by selecting one of (1) each of the plurality of scan tasks on the scan wait queue, (2) a predetermined number of the plurality of scan tasks on the scan wait queue, and (3) a set of scan tasks of a similar type on the scan wait queue; selecting from the scan task queue a first scan task from the plurality of scan tasks according to an order; and performing the scan task.