Using Consistency Management Protocols Over a Communication Management Protocol

In collaborative environments, sharing notion is everywhere. Concurrency management protocols become very important. We have defined the Chameleon protocol which allows us to obtain a dynamic management of the collaborative architecture on the one hand, and on the other hand, we have improved our consistency management protocol and rendered it optimistic: the Pilgrim and the Optimistic Pilgrim. The originality of the Chameleon is to allow the virtual topology to be reconfigured dynamically Pilgrim protocol and its optimistic version Optimistic Pilgrim protocol manage shared data consistency over our CSCW platform. They are based on a token over a logical ring of sites and ownership mechanisms: each shared parameter has one site which is its owner. Nevertheless, problems may appear when one site becomes inactive according to the Chameleon. Indeed, if this site is the owner of a shared parameter according to one of the versions of the Pilgrim protocol, there may be ownerless shared parameters. Consequently, we have studied and analyzed the cases in which that kind of problem may occurs through a coloured Petri net model. Thus, all the protocols have been modified in order to work well together