Abstract: In order to execute a plurality of transactions using a plurality of computers connected in a network, a plurality of distribution arrangements are defined and stored in one of the computers, which acts as a management computer. Each distribution arrangement corresponds to a predetermined distribution of the transactions among the computers. One of the distribution arrangements is distributed to all the computers, and transactions executed on the basis of that distribution arrangement. Subsequently, a further distribution arrangement is distributed to the computers so that, when a suitable change-over conduction occurs, the transactions may be executed on the basis of the further distribution arrangement. The change-over condition may correspond to a particular time, failure of one of the computers, expansion of the network, or overload. In this way, the network may adapt to different circumstances without excessive processing being required.

Abstract: The present invention provides a non-stop data processing system having an online data backup function. The method according to the present invention is a data backup method for a computer system having a central processing unit for performing multitask processing, a multiple memory constituted by a plurality of memory devices for online storing data processed by tasks of the central processing unit, and a data backup memory for saving data of the multiple memory, wherein the central processing unit performs parallel processing of (a) user task(s) to treat usual work between the central processing unit and the multiple memory and a maintenance task to save data online from memory devices as a part of the multiple memory to the data backup memory.