Patent ID: 8099398

Claim:
A data processing system, comprising: a plurality of database servers that are connected with each other via a network; and a plurality of data storage areas that store data of the database servers, wherein: each of the database servers comprises: an area management unit that holds an information related to the data storage area allocated to the database server; and a data processing unit that stores data in the data storage area held by the area management unit, refers to and updates the stored data, and, upon the update, stores a log indicating an update history of the data in a log area set respectively for the database servers in advance; and one of the plurality of database servers comprises: an area allocation management unit that allocates the plurality of data storage areas to the plurality of database servers; an instruction unit that notifies other database severs of the data storage areas which said area allocation management unit allocated and transmits an instruction to other database servers to reflect a change of the allocation of the data storage areas when said area allocation management unit changes the allocation of the data storage areas; and a restoration control unit that reads a log from log areas set respectively for the database servers and instructs other database servers to apply the log the restoration control unit read, upon a restoration process, wherein the area management unit stores a area remapping log indicating the change of the allocation of the data storage area upon receiving a notification of a change of the allocation of the data storage area from the area allocation management unit if said area allocation management unit have changed the allocation of the data storage area, wherein the restoration control unit reads the area remapping log from the log areas and determines the log, which each of the database servers applies to the data storage area, based upon the area remapping log, and wherein the data processing unit applies the log determined by the restoration control unit, according to the instruction from the restoration control unit.