Adaptive client side object replication for response time improvement in pervasive environments

Due to the high cost of replication, incurred mainly by consistency management, it may be infeasible to use uninformed object replication in collaborative applications in pervasive environments, since resources are constrained, nodes are heterogeneous, and application behaviour is highly dynamic. Consequently, this paper proposes an adaptive replication scheme that dynamically creates and releases replicas on client nodes during runtime, with the objective of improving response time performance. This is based on both the runtime information of the execution environments, and application behaviours of both client and server nodes. The adaptive replication algorithm is simulated with resource utilisation and response times compared to no replication and full replication schemes. Results show that the adaptive scheme is able to improve response time in a greater range of execution contexts than either no or full replication, while introducing less synchronisation overhead than the full replication scheme