A model for interface groups

How a model for interface groups can be integrated with the ANSA computational model is discussed. The result is a uniform model for one-to-one, one-to-many, many-to-one, and many-to-many communication. Whether a service is provided by a single server or distributed over a collection of servers cannot be inferred from the interface to the service. The proposed model thus provides full transparency of groups, and-if groups are used to support replication-full replication transparency. The interface group model is more general than those of ISIS and CIRCUS. In the prototype implementation of interface groups, the multi-endpoint communication protocol is implemented on top of a communication package with synchronous RPCs. The protocol ensures total order if a client uses RPC or no order if a client uses asynchronous calls