JGroupSpace: Combining Shared Spaces and Groups

We describe a Java-based distributed group programming interface - JGroupSpace. Its distinctive characteristic is the combination of multiple forms of communication within the group, based on message-passing, asynchronous event notification and a shared tuple space, and their integration to ensure the consistency of the views observed by the group members. For the application developer these communication forms match typical interaction patterns: point-topoint, multicast, events, and information sharing. In the model, groups act as confined spaces for interaction and cooperation, allowing the design of a distributed application in terms of multiple collections of cooperating processes. We describe how JGroupSpacewas implemented on top of an existing group communication platform - JGroups - and we discuss alternative distributed implementations of the group shared tuple space.