When we face issues in GoldenGate extract or replicat setup, we follow some of the tried and tested initial troubleshooting steps mentioned below that helps us in pointing out the exact case of the issue.
To start with, GGSCI commands which are useful for Gathering evidences of issue:
• SEND <group>, STATUS shows current processing status. • STATS <group> shows information about operations processed. • INFO ALL shows status and lag for all Manager, Extract, and Replicat processes on the system. • INFO <group>, DETAIL shows process status, data source, checkpoints, lag, working directory, files containing processing information. • INFO EXTRACT <group>, SHOWCH Checkpoint details on the Extract side • INFO REPLICAT <group>, SHOWCH Checkpoint details on the Replicat side • VIEW REPORT <group> Shows the report for specific group (extract or replicat)
Another most important place where you should looks is the Oracle GoldenGate Event Log (aka GGSCI error log file)
In this log file you will be able to see :
• History of GGSCI commands
• Processes that got started and/or stopped
• Errors that occurred during extract/replication
• Informational messages which shows what events lead to an error.
You can view this event log file by:
■ Using standard text editor or shell command like VI editor.
■ GGSCI command > VIEW GGSEVT
■ Oracle GoldenGate Director
Oracle GoldenGate Discard file is another important file that you should focus on:
NOTE: In 11g, this file is created only if the DISCARD FILE <filename> parameter is used in the Extract/Replicat parameter file. In 12C , this file is created by default when defining any extract/replicat process.
Key points about discard file:
• Created when Extract or Replicat has a problem with the record it is processing
• Contains column-level details for operations that the GoldenGateprocess could not handle
• Usually used for Replicat to log operations that could not be reconstructed or applied
• Can help in pointing out the data mapping issues
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