An Energy-Efficient Redundant Execution Algorithm by Terminating Meaningless Redundant Processes

It is critical to discuss how to realize not only energy-aware but also robust clusters of servers. A client usually issues a request to one server in a cluster and the server sends a reply to the client. Once the server stops by fault, the client does not receive a reply of the request and might be suspended to wait for a reply. Hence, each request is redundantly performed on multiple servers to be tolerant of server faults. In our previous studies, multiple servers are selected to redundantly and energy-efficiently perform a request process in the redundant power consumption laxity-based (RPCLB) algorithm. Here, since each application process is redundantly performed on more than one server, the larger amount of electric power is consumed. In this paper, we newly propose the improved RPCLB (IRPCLB) algorithm where once a process successfully terminates on one server, meaningless redundant processes are not performed on the other servers. We show the total power consumption of servers is reduced in the IRPCLB algorithm while the execution time of processes is almost the same as the RPCLB and round-robin (RR) algorithms.