10,474,695 - Method for replacing a currently operating data replication engine with a new data replication engine without application downtime and while preserving target database consistency
Abstract:An automated method is provided for replacing a currently operating data replication engine with a new data replication engine. A currently operating data replication engine reports its audit trail position upon stopping. The new data replication engine starts and is positioned at an audit trail position which is prior to the reported stopped audit trail position by an amount of the audit trail which corresponds to time that is equal to or greater than a source database transaction abort timer. The position of the new data replication engine to the stopped audit trail position defines a position window. Audit trail transactions are processed in the position window by the new data replication engine by ignoring transactions which committed or aborted in the position window, and replicating remaining transactions in the position window from the source database to the target database. The new data replication engine replicates all transactions that are started after the stopped audit trail position.