Patent attributes
According to an embodiment, database system includes nodes that communicate with each other to elect one node among the nodes, serving as a management device. The management device includes first and second assigning units. Depending on change in state of each node, the first assigning unit assigns a first node storing data pieces and receiving an access request to the data pieces, and assigns a second node storing the data pieces and serving as a backup node for the first node, and instructs each node to perform operations according to assignment. Depending on the state of nodes and a change in assignment state of the first and second nodes, the second assigning unit assigns a third node as a candidate node to serve as the first or second node, and instructs each node to make preparation for causing the third node to operate as the first or second node.
