This study discusses the issue of providing tolerance to hardware and software faults in Internet system as well as issues related to clusterization of servers. A replication scheme is presented, and a detailed dependability analysis of this scheme is performed. The proposed model was designed mainly for fault-tolerant internet system where many unrelated applications could compete for hardware and software resources, thereby exhibiting highly varying and dynamic system characteristics. A major feature of the model under consideration is to attempt the adaptive execution of redundant components for a required level of fault tolerance.