Method Partitioning - Runtime Customization of Pervasive Programs without Design-time Application Knowledge

Abstract

Heterogeneity, decoupling, and dynamics in distributed, component-based applications indicate the need for dynamic program customization and adaptation. Method Partitioning is a dynamic unit placement based technique for customizing performance-critical message-based interactions between program components, at runtime and without the need for design-time application knowledge. The technique partitions message handling functions, and offers high customizability and low-cost adaptation of such partitioning. It consists of (a) static analysis of message handling methods to produce candidate partitioning plans for the methods, (b) cost models for evaluating the cost/benefits of different partitioning plans, (c) a Remote Continuation mechanism that "connects" the distributed parts of a partitioned method at runtime, and (d) Runtime Profiling and Reconfiguration Units that monitor actual costs of candidate partitioning plans and that dynamically select "best" plans from candidates. A prototypical implementation of Method Partitioning the JECho distributed event system is applied to two distributed applications: (1) a communication-bound application running on a wireless-connected mobile platform, and (2) a compute-intensive code mapped to power- and therefore, computationally limited embedded processors. Experiments with method Partitioning demonstrate significant performance improvements for both types of applications, derived from the fine-grain, low overhead adaptation actions applied whenever necessitated by changes in program behavior or environment characteristics.