Comparison of stability and queueing times for reader-writer queues

A reader-writer queue manages two classes of customers: readers and writers. An unlimited number of readers can be processed in parallel; writers are processed serially. Both classes arrive according to a Poisson process. Reader and writer service times are general iid random variables. There is infinite room in the queue for waiting customers. s paper, a reader-writer queue is considered under the following priority disciplines: strong reader preference (SRP), reader preference (RP), alternating exhaustive priority (AEP), writer preference (WP), and strong writer preference (SWP). Preemptive priority is given to readers under the SRP discipline, or to writers under the SWP discipline. Non-preemptive priority is accorded to readers with the RP discipline, or to writers with the WP discipline. For the AEP discipline, customers of a given class are served exhaustively in an alternating fashion. e five priority disciplines, a stability condition and first moments for the steady-state reader and writer queueing times are given. Using these analytical results, each of the five priority disciplines is seen to be optimal (among the five) in some region of the parameter space. Simulation results are also presented.