DISTRIBUTED TRANSACTION PROCESSING USING TWO-PHASE COMMIT PROTOCOL PROVIDED WITH ASSUMPTION COMMIT WITHOUT LOG FORCE

摘要

PURPOSE: To eliminate the forced write of a log record by a regulator in a distributed transaction processing system using an assumed commitment 2-phase commitment protocol. CONSTITUTION: When transaction is allocated with its identifier (TID) in an ascending order and transaction already prepares commitment, a commitment command is sent to a regulator process. Then the regulator process executes at a site with a permanent storage device and a nonvolatile memory to decide whether TID of commit-prepared transaction exists within the selection range. Then if TID of commit-prepared transaction exists within the selection range, the regulator process sends a preparation message to a subordinate slave process but if TID of commit-prepared transaction does not exist within the selection range, the regulator process writes a nonvolatile log record in the permanent storage device by including the log record of commitment-prepared transaction so that TID may exists within the selection range before sending the preparation message to the subordinate slave process.