Jon A Preston

Computer Science PhD Graduate

Georgia State University

Motivated by configuration management systems, such as Revision Control System (RCS), that employ pessimistic concurrency techniques to avoid the problems of merging conflicting, concurrent changes made to shared documents, we revisit the idea that pessimistic locks offer potential collaborative editing system (CES) research opportunities.  We recognize that using pessimistic locks reduces the concurrent access, thus the CES community has lately focused on the optimistic approach that requires OT and similar merging techniques; but what if the locks were dynamic and could grow and shrink automatically?  By dynamically managing lock granularity, we may allow maximum concurrent access among many authors and avoid the need to merge disparate versions of the shared document, which can not be resolved occasionally.

This research focuses on developing an open-system architecture via Web services to combine heterogeneous client editing and server repository tools.  Further, we develop a set of distributed, peer-to-peer algorithms to dynamically manage pessimistic locks for multiple users within the CES.  Our techniques also allow for the incorporation of operational transformation (OT) approaches.  The consistency, causality preservation, and intention preservation (CCI) model is assured using delayed/relaxed intermediate consistency among the distributed peers, and all users are guaranteed to have the most current copy of the portion(s) of the shared document that they are currently viewing.

Current Work

Defense Related Documents (May 2007)

Publications and Presentations

Conference Date Location Paper Presentation
HiPC 2007 Dec 18-21, 2007 Goa, India P2P Document Tree Management in a Real-Time Collaborative Editing System  
DEVS'07 Mar 25-29 Norfolk, VA Simulation-based Architectural Design and Implementation of a Real-time Collaborative Editing System Presentation
CollaborateCom 2006 Nov 17-20, 2006 Atlanta, GA An Efficient Synchronous Collaborative Editing System Employing Dynamic Locking of Varying Granularity in Generalized Document Trees Presentation
IWCES 2006 Nov 4, 2006 Banff, Canada Achieving CCI Efficiently by Combining OT and Dynamic Locking with Lazy Consistency in a Peer-to-Peer CES Presentation
CSCW 2006 Nov 4-8, 2006 Banff, Canada Synchronous Editing via Web Services: Combining Heterogeneous Client and Server Technologies Presentation
CIC 2006 Oct 25-27, 2006 Hong Kong A Web-Service-based Open-Systems Architecture for Achieving Heterogeneity in Synchronous Collaborative Editing Systems Presentation
IWCES 2005 Nov 6, 2005 Sanibel Island, FL A Deadlock-Free Multi-Granular, Hierarchical Locking Scheme for Real-time Collaborative Editing Presentation
ACMSE 2005 March 18-20, 2005 Kennesaw, GA Exploring Communication Overheads and Locking Policies in a Peer-to-Peer Synchronous Collaborative Editing System Presentation
DiMos Research Group Spring 2004 TSRB, Atlanta, GA Collaborative Editing Systems and their Application to Distributed Software Engineering Presentation

 

Proposal Related Documents (April 2006)

Qualifiers (November 2004)

Selected Course Work

Advanced Software Engineering - CSc8350 (Spring 2005)

Literature Research

Simulation

Parallel Algorithms - CSc8530 (Fall 2004)

Research

Presentations

Knowledge Management - CIS8260 (Summer 2004)

Other Links

P2P Debugging