A computer system having a plurality of computers for responding to a request from a client and a running management computer for managing said plurality of computers, wherein: the running management computer includes a storage unit and a processing unit; the storage unit stores a target value of performance information on a response time to the request, for each URL pattern of the request; and the processing unit monitors the performance information on the response time to the request, for each URL pattern of the request, and judges whether or not the monitored performance information read from the storage unit satisfies the target value of the performance information, to execute load distribution by moving a Web content corresponding to the URL pattern of the request not satisfying the target value of the performance information, to another computer.