Robustness and analytic computer system models

摘要

The use of simulation studies to investigate the behavior of computer hardware/software systems is well established, although in some sense analytic models are more desirable. Simulation is used in a situation which is completely intractable to analytic machinery, or for which the essence is lost when the prerequisite abstractions and simplifying assumptions necessary to the analytic technique are made. In this paper, the term analytic model is used to refer to that set of computer system models based upon queuing theory.

Many view the operating system as a network of resources each potentially precipitating queues. Such a view allows the units passing through the network to request (employ) the devices in various combinations in a multiprogramming environment. The computing system is thus viewed as sequences of resource seizures and releases (processors, memory and input-output equipment) with appropriate holding time assumptions. In many cases, the models indicate rather clearly how various policies and variables interact to effect system performance, and the predictions of some coincide well with measurable data.