Exception processing

Exception processing is the most effective way of identifying performance problems. The first step in monitoring your DB2® system should always be to start thread and statistics exception processing.

Use Online Monitor exception processing to identify Db2 thread and statistics fields with values outside defined thresholds. This allows better management of service levels by identifying problems in the Db2 subsystem and threads causing performance problems.

By using display exception processing and periodic exception processing, you can monitor and identify:
  • Threads that might be experiencing problems
  • Subsystem-wide Db2 conditions that might be causing performance problems
By using exception event processing, you can monitor the following events:
  • Deadlock
  • Timeout
  • EDM pool full
  • Authorization failure
  • Thread commit indoubt
  • Coupling Facility (CF) rebuild/alter start
  • CF rebuild/alter end
  • Global trace started

The threshold values for thread activity and statistics fields are specified in the Exception Threshold data set. When exceptions are detected during your monitoring session, you are notified so that appropriate action can be taken. In addition, you can activate a user exit that can automatically trigger any immediate reaction, for example, issue an alert to NetView®.

You can view information about any of the exceptions using the Online Monitor LOOK command.

With exception processing, you can create the following two data sets for later analysis:
  • The Exception Log data set (to print a list of exceptions or to load exception data into Db2)
  • The Exception DPMOUT data set (records that had exceptions)