COMPUTER SCALE-OUT METHOD, COMPUTER SYSTEM, AND STORAGE MEDIUM

A computer scale-out method by adding a second computer to a first computer receiving stream data from a data source and executing a query to make the second computer execute the query, the computer scale-out method including: receiving, by a management computer, a request to scale out; a second step of generating, by the management computer, rewritten queries that are copies of the query; sending, by the management computer, instructions to scale out including the rewritten queries to the first computer and the second computer; receiving, by the first computer and the second computer, the instructions to scale out, extracting the rewritten queries, and switching to the extracted rewritten queries; notifying, by the first computer or the second computer, the management computer of readiness of the rewritten queries; and sending, by the management computer, an instruction to add the second computer as a destination to the data source.