P2P-based Locking in Real-Time Collaborative Editing Systems

Real-time collaborative editing systems allow a group of users to view and edit the same document at the same time from geographically dispersed sites connected by communication networks. Consistency maintenance in concurrent access of shared objects is one of the key issues in designing these types of systems. This paper proposes a P2P-based locking schema for concurrency control in internet-based real-time collaborative editing systems. This schema can distribute locking services to all collaborative sites and quickly find out the locking service nodes of given shared objects. The characteristic of distributed locking services solves the hot spot problem in centralized locking schema, and the capability of quickly locating locking service nodes resolves the broadcast communication problem in the existing distributed locking schemas. It also provides the basic locking function in collaborative editing systems and can be used in varied locking polices.