The Improved Redundant Delay Time-Based (IRDTB) Algorithm to Perform Computation Type Application Processes in Heterogeneous Server Clusters

摘要

In fault-tolerant information systems, application processes have to be reliably performed in presence of server faults. Server cluster systems are widely used to realize not only high performance but also fault-tolerant service. In order to reliably perform application processes, multiple replicas of each application process are performed on multiple servers in a server cluster system. On the other hand, the larger amount of electric energy is consumed in a server cluster system since multiple replicas of each application process are performed on multiple servers. The redundant delay time based (RDTB) algorithm is discussed to select multiple servers to redundantly perform each application process in a homogeneous server cluster so that the total energy consumption of the server cluster can be reduced. In a homogeneous cluster, every server follows the same computation model and power consumption model. On the other hand, servers follow different types of computation models and power consumption models in a heterogeneous server cluster. Hence, a load balancer cannot precisely estimate the processing load and energy consumption of each server in a heterogeneous server cluster by the RDTB algorithm. In this paper, we propose an improved RDTB (IRDTB) algorithm to select multiple servers for redundantly performing each application process so that the total energy consumption of a server cluster and response time of each process in a heterogeneous server cluster can be reduced. We evaluate the IRDTB algorithm compared with the RDTB algorithm in a heterogeneous server cluster. In the evaluation, we show the average total energy consumption of a heterogeneous server cluster in the IRDTB algorithm can be reduced maximum 44% of the RDTB algorithm.