Web caching is an important technology for reduc- ing Internet access latency, alleviating network traf- fic, and spreading server load. An important issue that affects the performance of web caching is caching architecture, in which several caches are usually fed- erated for making caches cooperate on a large scale and effectively increase the cache population. Trans- parent data replication is such a caching architec- ture, which has shown to be easy to manage and have good system scalability. In this paper, we present an survey of state-of-the-art techniques of cache/proxy placement for transparent data replication.