Asynchronous Migration of Process Replicas in a Cluster

Application processes have to be efficiently and reliably performed on servers in a cluster. A process is replicated to increase the reliability and availability. However, the more number of replicas of a process are performed, the more reliable and available the system is but the more amount of electric energy is consumed. In this paper, we take a process migration (MG) approach to energy-efficiently and reliably performing an application process on servers in a cluster. A process performed on a current server is migrated to another server if the server is expected to consume a smaller amount of electric energy to perform the process than the current server while the deadline constraint of the process is satisfied. In order to reliably perform a process, multiple replicas of the process are performed on different servers. We consider synchronous and asynchronous ways to migrate process replicas to servers. In the synchronous migration, every replica moves to another server on a same computation state. In the asynchronous migration, each replica by itself makes a decision on when the replica is migrated to another server.