Abstract: Among computers which are monitored mutually, originating from an arbitrary computer, the state is inquired sequentially according to a ring sequence list, and state information is updated in every inquiry. Accordingly, the state information is shared among all the computers.

Abstract: A data communication apparatus which allows a file to be shared among a plurality of personal computers (hereinafter referred to as “PC”) without using a file server, a Web server, or the like. According to the data communication apparatus, a inquiry executing section 6 on PC#1 (2) makes an inquiry to each of other PCs #2 to #n whether or not a file matching a specific keyword is stored in the shared files 30 stored in themselves. A search executing section 7 on each of the other PCs#2 to #n searches an index file 4 to search the file. The search executing section 7 returns a search result to PC#1. A search result receiving section 8 on PC#1 receives the search result. A file transmission requesting section 9 on PC#1 requests one of the other PCs to transmit a given file among files shown in search results received.

Abstract: A cluster controlling system transfers packages which have been operating on one computer to another computer when a fault or failure has occurred by monitoring and controlling the packages in the entire system. When the respective packages are started-up, cluster daemons on the respective computers monitor and control resources on the operating computers. The monitored and controlled data are stored in the respective computers as local data. A manager communicates with cluster daemons on the respective computers, and stores data in a global data memory to monitor and control the entire system. The manager is actually one of the packages operating in the cluster system. If a fault or failure occurs in the manager or in the computer running the manager, the manager is re-started on another computer by a cluster daemon.