Troubleshooting Guide

Chapter 9. Troubleshooting Replication

Replication is a process of maintaining a defined set of data in more than one location. It involves copying designated changes from one location (called a source) to another (called a target), and synchronizing the data in both locations. The source and the target can be in logical servers on the same machines or on different machines in a distributed network.

DB2 DataPropagator provides the following facilities when troubleshooting problems:

• The Replication Analyzer which analyzes replication control tables, change data tables, target tables, and target table indexes for accuracy, consistency, and efficiency. Findings from the analysis are reported in a HTML file.
• Error messages and SQL states for the DB2 Control Center, the Capture program, and the Apply program
• The Apply program trail table (ASN.IBMSNAP_APPLYTRAIL on the control server database), log file (*.APP) and trace file (*.TRC). The trcflow or trcerr parameters can be used with the asnapply command to produce a trace.
• The Capture program trace table, log file and trace file. The trace parameter can be used with the asnccp command to produce a trace.
• The IBM Replication control tables and files.

When testing or troubleshooting replication problems, you should use these cautionary practices:

• Always work on replication scenarios in a test environment.
• Stop other replication activity while gathering information about a problem to reduce the volume of data that surrounds the actual problem.

There are two areas where problems could occur:

• During the administration of the replication environment using the Control Center or the DB2 DataJoiner Replication Administration (DJRA) tool.
• During the running of the Capture and Apply programs. For example, to get more information on ASNnnnnn errors, run db2 ? ASNnnnnn where nnnnn is the message number.

Details about the facilities available to identify and solve replication problems and Apply and Capture messages are found in the Replication Guide and Reference manual.