Commentary - The Silver Bullet

When addressing acceptance of a parallel computing technology by the general simulation community, the issue of performance cannot be overlooked and is difficult to overexaggerate. So, how does this relate to Fujimoto's paper? Fujimoto identifies “easing the amount of work and expertise required to parallelize simulation applications” as his primary point of departure and focuses on four silver bullets. “Alleviating concerns about performance” is not among them. Yet, if there is a silver bullet, this is it. What I mean by “alleviating performance concerns” is this: if an environment existed where simulationists could develop parallel simulations with automated support for difficult tasks such as synchronization and communication, and the acceptability of the performance of the resulting simulation execution did not hinge on the performance of the automated portions, then performance concerns have been alleviated. Ideally, the performance of the entire simulation would be acceptable, but programmers can be finicky. Later I employ a borrowed virtual memory analogy to clarify my goal. The difference between what Fujimoto and I consider important is not a matter of content as much as it is a matter of focus. I propose an ideal environment, where the environment is a vehicle for expressing my goals about alleviating performance concerns. Fujimoto discusses languages and identifies requirements that would make the languages better. Both of us conclude by pinpointing similar needs for different reasons. I contend that Fujimoto's presentation leaves the reader with too vague a focus. Many of the issues about languages, application libraries and the like can wait. The research focus needs to be on one central issue: alleviate performance concerns. Solve that and the rest will follow. In the remainder of this commentary, I discuss the limitations of Fujimoto's silver bullets as goals unto themselves and then elaborate on the issues involved in addressing performance concerns and discuss why this issue is central. INFORMS Journal on Computing, ISSN 1091-9856, was published as ORSA Journal on Computing from 1989 to 1995 under ISSN 0899-1499.