1. A computer system comprising a plurality of computers coupled through a network, the computer system performing service by using a database constructed by a storage area of each of the plurality of computers, wherein each of the plurality of computers includes a processor, a memory coupled to the processor, and a network interface for communicating with another computer via the network which is coupled to the processor, and a plurality of pieces of data are located in the plurality of computers constructing the database based on a distributed algorithm for distributing and locating the plurality of pieces of data in the plurality of computers, the plurality of pieces of data including a key and a data value are stored in the database, and the distributed algorithm is an algorithm for determining a management range which is a range of the key, wherein the computer system comprises: a load information management part to manage load information on a load of each of the plurality of computers constructing the database; an algorithm management part to switch the distributed algorithm of the computer system based on the load information; and a relocation processing part to relocate data stored in each of the plurality of computers based on the switched distributed algorithm, wherein the relocation processing part is configured to: determine whether a piece of first data is included in the management range of a first computer based on the switched distributed algorithm, in a case where the first computer receives an access request for the piece of first data after the distributed algorithm is switched, determine whether the piece of first data is stored in the first computer, in a case where it is determined that the piece of first data is included in the management range of the first computer, and obtain the piece of first data from the other computer which stores the piece of first data, in a case where it is determined that the piece of first data is not stored in the first computer, and the algorithm management part is configured to switch the distributed algorithm, in a case where a load of a computer constructing the database is equal to or larger than a predetermined threshold, or in a case where the load of the computer constituting the database equal to or smaller than a predetermined threshold.