Content Delivery Policies in Replicated Web Services: Client-Side vs. Server-Side

Replication of Web Services has an important role among techniques that have been developed in order to meet the demand for faster and more efficient access to the Internet. Replication can be addressed both by a cluster of servers, and by servers geographically distributed in the Internet. In this paper, we focus on geographical replication. Two approaches are commonly used for geographical replication: server-side and client-side. In the client-side approach, the client has a significant role in the policy used to exploit Web Service Replication. In the server-side approach, the client transparently exploits a Replicated Web Service. Both server-side and client-side approaches provide various strategies that can be adopted. An analysis of these strategies, and an overall classification, is presented here. Finally, client-side and server-side approaches are compared, identifying their pros and cons in order to propose the features of an eventual complete approach.