METHOD AND DEVICE FOR KEEPING CONSISTENCY OF SPACE SHARED WITH MULTIPLE END-POINTS ON P2P COOPERATIVE COMPUTER SYSTEM WHICH EXCHANGES INSTRUCTION AND DATA BLOCK DIRECTLY

摘要

PURPOSE: A method and a device for keeping consistency of a space shared with multiple end-points on a P2P(Peer-to-Peer) cooperative computer system are provided to directly exchange instructions and data blocks in order to keep the consistency of the space shared with common collaborators. CONSTITUTION: Each end-point(400) keeps a local data copy(438) and updates the local data copy by transmitting a data update command including in the delta with each other. A consistency delta log data structure placed to each end-point stores the data and corresponding contents. A mechanism installed to each end-point makes each delta received from the end-point form a chain depending on a generating/receiving order, while each delta generated/received from other end-point is inserted into a delta log. The mechanism selectively cancels/re-executes the data update command by using the contents of the delta log in order to make all end-points attain convergence of the data update command, while the data update command in the delta is executed.