Control exception messages from background samplers

Background sampling is used to detect exception conditions in critical Db2 system resources (such as the logs or buffer pools) and also to detect thread exceptions during execution (runaway queries) that could be serious enough to impact Db2 performance.

Exception messages are shown on the Db2 Exception panel (DB2EX service) while the condition exists, and are displayed chronologically on the LOG DISPLAY.

Related topic

Customizing-background-processing

By default, exceptions are activated. To control the number and type of exceptions for which the background sampler scans, specify the criteria for any background sampler message in BBPARM member DMRBEXxx. For any specified target (the default is the first target defined in BBPARM member BBIJNT00), you can inactivate or control the conditions for a specific message.

In the following example if a TSO query is using more than 2 seconds of CPU time or if there are more than 1000 GETPAGES and if either or both of these two conditions have been true for the last four cycles, the message DZ0630W identifying that TSO user is displayed on the Db2 EXCEPTION panel and on the associated BBI-SS PAS’s LOG DISPLAY panel.

Example
TARGET=DB2A
MSG=DZ0630W,CPU=70,GPRATE=100,CYCLES=3       COMBINED CONTROLS ALLOWED         
MSG=DZ0620W,CPUTOT=200,ELAPSED=180     



Important

At present, a cycle is defined as approximately 5 seconds.

See BBPARM member DMRBEX00 for a complete description of options and syntax, definitions of each exception condition, and instructions for disabling a particular message or message threshold. For more information, see Using Alarm Management.

 

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