A flexible hybrid concurrency control model for collaborative applications in large scale settings

Large-scale collaborative applications are difficult to build because of their high concurrency control needs and the heterogeneity of the underlying architecture. Due to these difficulties, only a few large-scale applications have been developed, such as Usenet or irc. To facilitate the realisation of such applications, we propose a more precise definition of the application's needs, in order to provide a good "quality" of cooperation when it is needed, and cheaper cooperation when it is acceptable. The model of LaSCoW (Large Scale Collaborative Work) allows the applications to be partitioned into separate consistency domains, each domain implementing its own collaboration policy.