Parallel queues with synchronization

Abstract

Motivated by the growing interest in today's massive parallel computing capabilities we analyze a queueing network with many servers in parallel to which jobs arrive a according to a Poisson process. Each job, upon arrival, is split into several pieces which are randomly routed to specific servers in the network, without centralized information about the status of the servers' individual queues. The main feature of this system is that the different pieces of a job must initiate their service in a synchronized fashion. Moreover, the system operates in a FCFS basis. The synchronization and service discipline create blocking and idleness among the servers, which is compensated by the fast service time attained through the parallelization of the work. We analyze the stationary waiting time distribution of jobs under a many servers limit and provide exact tail asymptotics; these asymptotics generalize the celebrated Cramér-Lundberg approximation for the single-server queue.