A computer system, comprising a plurality of computers coupled to one another via a network, the computer system being configured to execute a business task using a database constructed from storage areas include in each of the plurality of computers, the database being configured to store a plurality of pieces of data, each piece including information identifying the piece of data, a value of the piece of data, and a sequence number which is a value indicating an execution order of events in the database, wherein the plurality of pieces of data are allocated in a distributed manner across each of the plurality of computers for each management area determined by applying a partitioning algorithm for a distributed data store to the information identifying the data; each of the plurality of computers including; a data management module configured to manage the allocated data; a data control module configured to determine the sequence number of an operation on the allocated data; and a recovery control module configured to transmit replicated data of data included in a predetermined management area to a newly added computer, wherein the plurality of computers includes a first computer (100·3) as the newly added computer configured to transmit a recovery request and a second computer (100·1) configured to receive the recovery request, characterized in that the second computer is configured to execute: a data replication processing, when upon receiving the recovery request from the first computer, a state of the second computer is shifted to a recovery state, wherein in the data replication processing at least one piece of data is read from the database of the second computer based on the sequence number and transmitted to the first computer as first replicated data; and if, while in the recovery state, the second computer (100-1.) receives a command to update the data which is included in data to be replicated, the data replication processing is temporarily interrupted and an update processing is performed, wherein in the update processing the second computer updates the sequence number of predetermined data and the predetermined data based on the update command, and the updated predetermined data only is transmitted to the first computer as second replicated data. the computer system being configured to execute a business task using a database constructed from storage areas include in each of the plurality of computers, the database being configured to store a plurality of pieces of data, each piece including information identifying the piece of data, a value of the piece of data, and a sequence number which is a value indicating an execution order of events in the database, wherein the plurality of pieces of data are allocated in a distributed manner across each of the plurality of computers for each management area determined by applying a partitioning algorithm for a distributed data store to the information identifying the data; each of the plurality of computers including; a data management module configured to manage the allocated data; a data control module configured to determine the sequence number of an operation on the allocated data; and a recovery control module configured to transmit replicated data of data included in a predetermined management area to a newly added computer, wherein the plurality of computers includes a first computer (100·3) as the newly added computer configured to transmit a recovery request and a second computer (100·1) configured to receive the recovery request, characterized in that the second computer is configured to execute: a data replication processing, when upon receiving the recovery request from the first computer, a state of the second computer is shifted to a recovery state, wherein in the data replication processing at least one piece of data is read from the database of the second computer based on the sequence number and transmitted to the first computer as first replicated data; and if, while in the recovery state, the second computer (100-1.) receives a command to update the data which is included in data to be replicated, the data replication processing is temporarily interrupted and an update processing is performed, wherein in the update processing the second computer updates the sequence number of predetermined data and the predetermined data based on the update command, and the updated predetermined data only is transmitted to the first computer as second replicated data. a data replication processing, when upon receiving the recovery request from the first computer, a state of the second computer is shifted to a recovery state, wherein in the data replication processing at least one piece of data is read from the database of the second computer based on the sequence number and transmitted to the first computer as first replicated data; and if, while in the recovery state, the second computer (100-1.) receives a command to update the data which is included in data to be replicated, the data replication processing is temporarily interrupted and an update processing is performed, wherein in the update processing the second computer updates the sequence number of predetermined data and the predetermined data based on the update command, and the updated predetermined data only is transmitted to the first computer as second replicated data.