| 摘要 |
This stream data processing system comprises: an input server which accumulates input stream data to be migrated (hereinafter referred to simply as data), instructs a migration source and a migration destination to perform data migration, transfers accumulated data to the migration destination in response to an accumulated data transfer instruction, then stops transferring data to the migration source, and transfers subsequent data to the migration destination subsequently to the transfer of the accumulated data; the migration source which, in response to the migration instruction, migrates, to the migration destination, both a query for processing data to be migrated transferred from the input server, and an intermediate value that has been produced as a result of completion of execution of the query on input data, and which, in response to a query execution stop instruction from the migration destination, stops the execution of the query and transfers query execution results to the migration destination; and a migration destination server which, in response to the migration instruction, begins to execute the query migrated from the migration source, and reads the accumulated data and the subsequent data that are transferred from the input server, in such a manner that the migration destination server skips reading the portions of these transferred data corresponding to and preceding the migrated intermediate value, thus discarding the output that is transferred from the migration source and that precedes the query execution results. |
