Using Smart Clients to Build Scalable Services

Individual machines are no longer sufficient to handle the offered load to many Internet sites. To use multiple machines for scalable performance, load balancing, fault transparency, and backward compatibility with URL naming must be addressed. A number of approaches have been developed to provide transparent access to multi-server Internet services including HTTP redirect, DNS aliasing, Magic Routers, and Active Networks. Recently, however, portable Java code and lightly loaded client machines allow the migration of certain service functionality onto the client. In this paper, we argue that in many instances, a client-side approach to providing transparent access to Internet services provides increased flexibility and performance over the existing solutions. We describe the design and implementation of Smart Clients and show how our system can be used to provide transparent access to scalable and/or highly available network services, including prototypes for: telnet, FTP, and an Internet chat application.