Communicating object group and protocols for distributed systems

Distributed communicating object groups, relevant algorithms and object communication protocols are presented. The distributed communicating object group system (called DCO) is built on the basis of hierarchy group communication protocols for networks. The system can be used as a speci®cation and design environment for distributed fault-tolerant object-oriented (OO) applications. By combining distributed process group with the powerful OO concepts, the novelty of DCO lies in its provision of methodology for construction of communicating object groups, reliable communication protocols, group membership and management. The mechanisms of grouping user objects enable application objects to communicate transparently over network. Communication details implemented by underlying group multicast protocol are thus hidden from users. This makes the objects completely responsible for their modi®cation, protection, execution and communication. DCO is used to relieve application designers from diculty of designing object communication and reliability. Multiple layers of object group protocols are given and their design and implementation experiences are presented. Ó 1999 Elsevier Science Inc. All rights reserved.