Replication Agent for DB2 UDB product fits into a replication system as follows:
The primary data server is DB2 UDB, which runs as a subsystem in IBM z/OS. The transaction logs are DB2 logs.
Replication Agent for DB2 UDB runs as a started task or job in IBM z/OS. It reads the DB2 logs and retrieves the relevant DB2 active and archive log entries for the tables marked for replication for one or more DB2 subsystems. It transfers that data to Replication Server using the TCP/IP communication protocol.
The DB2 data server logs any changes to rows in DB2 tables as they occur. The information written to the transaction log includes copies of the data before and after the changes. In DB2, these records are known as “undo” and “redo” records. Control records are written for commits and aborts; These records are translated to commit and rollback operations.
The DB2 log consists of a series of data sets, which Sybase Log Extract uses to identify DB2 data changes. Because DB2 writes change records to the active log as they occur, Sybase Log Extract can process the log records immediately after they are entered.
