Abstract: A management server for managing a plurality of servers dynamically selects, from among the plurality of servers, a second server which is not allocated, and which corresponds to a first server to execute a jobnet for batch processing, then the management server sets a server environment, in the selected second server, which is a server environment in the first server, executes each job forming a jobnet on the first server and the second server in which the server environment has been set respectively, and releases the second server when execution end notification for the jobnet is received from the first server and the second server respectively.

Abstract: The present invention reduces the processing time required for alltoall communications in a parallel computer. When performing alltoall communications in a parallel computer, the number of transfer data units and the number of computers are used as parameters to select between a method where a temporary work buffer is allocated in the memory of each computer and non-contiguous data is exchanged between computers and a method where data is exchanged between computers without allocating temporary work buffers.