Object-Oriented Programming Using SOM and DSOM/Using Replicated Objects

The Replication SOM (RSOM) Framework allows you to replicate an object in several different processes distributed across a network. Each replica of the object can be updated, and the Framework handles the propagation of t.he update to all the other replicas. The updates are serialized by the Framework. and are propagated from the originating process to the other participants, without the use of secondary storage.

The RSOM Framework can be used to implement "groupware" type applications. For example, using the Replication Framework, a compound document consisting of text, diagrams, bitmaps, and graphics can be worked on collaboratively by multiple concurrent users located at different workstations on a network. Each user can see the changes made by others in the group. Traditionally. in a distributed environment, information sharing is achieved through the use of database servers. The Replication Framework provides a new way for sharing information that puts a user in direct contact with other users. Each user see:the changes made by others instantaneously.

Each replica is not aware of how many other replicas there are in the network, or where they are in the network. A participant canjoin or leave the group at any time, and the replicas in the network will not be aware of it. The Framework can tolerate process or node failure, and provides recovery.