Abstract
Replica is widely used in distributed systems and Replica Placement is critical for replica effectiveness. With rapid development of distributed applications, QoS becomes more and more important. In this paper, we give a survey on QoS-aware Replica Placement Problem (QRPP) for distributed system. Model and definition of QRPP are discussed. Existing solutions are described and analyzed in detail. In order to guide the design and implementation of QoS-aware replica service, a replica placement simulator called QARSS is specially developed to realize different algorithms. Finally, simulating experiments are executed on QARSS to investigate the quantitative characteristics of QRPP.