  We study a model of congestible resources, where pricing and scheduling are
intertwined. Motivated by the problem of pricing cloud instances, we model a
cloud computing service as linked $GI/GI/\cdot$ queuing systems where the
provider chooses to offer a fixed pricing service, a dynamic market based
service, or a hybrid of both, where jobs can be preempted in the market-based
service. Users (jobs), who are heterogeneous in both the value they place on
service and their cost for waiting, then choose between the services offered.
Combining insights from auction theory with queuing theory we are able to
characterize user equilibrium behavior, and show its insensitivity to the
precise market design mechanism used. We then provide theoretical and
simulation based evidence suggesting that a fixed price typically, though not
always, generates a higher expected revenue than the hybrid system for the
provider.
