From the angle of scalability and stability of computing ability, this paper gives the functionally distributed and symmetric architecture of server clusters for network applications, and discusses the various cluster architectures for implementing the fault tolerance of storage components. 本文从处理能力可扩展和容错的角度,给出了功能分布和对称的网络应用服务器集群结构,并讨论了实现存储部件容错的各种集群结构。