Object replacement using dynamic proxy updates

In a distributed environment, a client program bound to a server fails when the server changes (possibly due to the server being relocated, replicated or reconfigured). In this paper, we describe the design of an object-replacement scheme in a client-server environment. Our design addresses the problem of replacing a server and transparently updating the client handle so that no service interruption is experienced by the client. The programming environment, on which this work is based, provides passive shared objects, threads, and invocations as the building blocks for distributed applications. Our design takes into account the potential concurrency within clients and servers. Our task was relatively simplified by building the replacement mechanisms on top of an asynchronous event notification facility that handles events on a per-application basis, as opposed to a per-task or per-thread basis.