Improving Protocol Performance by Dynamic Control of Communication Resources

A problem frequently faced by complex distributed applications is the appropriate balance of their communication vs. computational activities. For example, in real-time applications, communications must interact with computations so that they jointly adhere to program-specific timing or QoS requirements.This research concerns the construction of communication protocols able to cope with the varying processing and QoS requirements imposed on them by application programs. We define and prototype a communication infrastructure, called COMMadapt, enabling protocols to adapt their processing and resource usage to current program requirements and available processing and network resources. The key feature of COMMadapt is the ability of dynamic (self-)configuration. Since COMMadapt assumes multi-threaded protocol implementation, we investigate how various program-level latency and throughput requirements can be supported by alternative assignments of protocol tasks to underlying processing resources. Such experimental insights are used to develop heuristics for connection- establishment time assignments and for on-line reconfiguration triggered by a connection's divergence from its initial specifications