Dynamic key messaging for cluster computing

Over the past decades, distributed computing has been gaining popularity. It provides more computing power and memory space for parallel applications. On the other hand, such applications fight back and challenge the architectures of the distributed systems for more efficiency. To face the challenge, a key messaging (KM) scheme was proposed to realize the optimization of communication at a system architecture level in our previous papers. The contribution of KM is that it performs the optimization in both the underlying communication system and high level application model. The performance of an application is always determined by its critical path. Currently, messages along the critical path can be easily blocked by non-critical path messages, which degrade the performance. To solve this problem, KM provides an algorithm to identify the critical-path messages and optimizes them by introducing a prioritized protocol layer. Thus, these messages are served first before any low priority messages. Shorter processing time for the messages results in faster completion time of the critical path. Although KM was proved to be effective by a prototype system on the IBM SP2, there are limitations in its optimization procedures where dynamic natures of an underlying network should be considered when running parallel applications on cluster/distributed computing environments. To address the problem, a dynamic key message (DKM) algorithm is introduced. DKM takes into considerations the changes of network traffic load while tasks are running and dynamically updates the critical path on the fly. A comprehensive simulation method is adopted to evaluate the performance of this algorithm and the results show that under the same workload, DKM exhibits much more stability than the static key message (SKM) algorithm when the network traffic load changes.