1. A method for operating a task broker in a network-based distributed computing system, the method comprising: receiving, from a processing resource, an indication of availability and, in response thereto; indicating, to the processing resource, a first pseudo-random wait time, after which the computational resource may again indicate its availability to the broker; receiving, from a job-submitting resource, an inquiry concerning the completion status of a job and, in response thereto indicating, to the job-submitting resource, that the job is not yet complete and indicating a second pseudo-random wait time, after which the job-submitting resource may again inquire about the completion status of the job; and selecting at least one of the first or second random wait times using a pseudo-random number generator, wherein a target distribution of the pseudo-random number generator is adjusted in response to the number of processing resources and job-submitting resources in active communication with the broker; wherein the pseudo-random number generator varies its target distribution in response to detected levels of network traffic in the distributed computing system; wherein the pseudo-random number generator generates the target distribution of the first pseudo-random wait time or the second random wait time using an algorithm to vary the first pseudo-random wait time or the second pseudo-random wait times so as to maintain a total aggregate polling rate within an operating range such that when more customer entities are active, the pseudo-random number generator increases the first pseudo-random wait time or the second pseudo-random wait time, and when fewer customer entities are active, the pseudo-random number generator decreases the first pseudo-random wait time or the second random wait time.