An efficient and flexible late join algorithm for interactive shared whiteboards

We propose a novel late join algorithm for distributed applications with a fully replicated architecture (e.g. shared whiteboards). The term 'late join algorithm' is used to denote a mechanism that allows a late-coming participant rejoin an ongoing session. Generally, this requires that participants in the session provide the latecomer with the current state of the shared application. We identify the key issues of late join algorithms and propose a set of requirements which a 'good' late join approach should satisfy. Based on these requirements, we evaluate existing late join algorithms and explain why we opted instead to develop a new, advanced late join algorithm for our own shared whiteboard. This late join approach is general enough to be used for arbitrary distributed applications.