Described embodiments provide rate setting for nodes of a scheduling hierarchy of a network processor. The scheduling hierarchy is a tree structure having a root scheduler and N scheduler levels. The network processor generates tasks corresponding to received packets. A traffic manager queues received tasks in a queue of the scheduling hierarchy associated with a data flow of the task. The queue has a parent scheduler at each level of the hierarchy up to the root scheduler. A scheduler selects a child node for transmission based on a number of arbitration credits in an arbitration credit bucket of each child. An arbitration credit value is determined for each child by maintaining a time stamp value corresponding to a time value of a previous selection of the child node and determining an elapsed time value based on the time stamp value and a current time value, scaled by a scaling factor.