When distributed processing is to be performed in a computer system, a processing node subjected to the distributed processing is properly selected. For this purpose, when distributed processing is to be performed between a plurality of computer apparatuses which are connected via a network and include a management node (501) for requesting distributed processing of a job, and processing nodes (502a to 502d) for executing the requested distributed processing and transmitting processing results to the management node, the management node requests test processing of the processing nodes (1), receives the processing results from the processing nodes (2), updates status information in a database (503) in accordance with the received processing results of the test processing (3), and refers to the status information to select a processing node of which distributed processing is to be requested (4).