Exposing application alternatives

We present the design of an interface to allow applications to export tuning alternatives to a higher-level system. By exposing different parameters that can be changed at runtime, applications can be made to adapt to changes in their execution environment due to other programs, or the addition or deletion of nodes, communication links, etc. An integral part of this interface is that an application not only exposes its options, but also the resource utilization of each option and the effect that the option will have on the application's performance. We discuss how these options can be evaluated to tune the overall performance of a collection of applications in the system. Finally, we show preliminary results from a database application that is automatically reconfigured by the system from query shipping to data shipping based on the number of active clients.