Db2 objects are backed by z/OS data sets. Whenever Db2 z/OS adds additional extents to a data set that backs a Db2 table or index space, for example if you do mass inserts into a table, an IFCID 258 event trace record is written if the appropriate Db2 trace is started. OMEGAMON for Db2 currently provides monitoring of these events in the Performance Expert Client and, with PTF UI91411, also in the Enhanced 3270 User Interface. 

To further extend the existing functionality, a new threshold value has been introduced to make the data set extent monitoring more flexible: you can collect events based on actual data set size rather than the extent number by using a percentage value. By specifying a percentage value in Configuration Manager (or PARMGEN) for the respective parameter, you tell OMEGAMON Db2 PE to collect IFCID 258 records only if the respective Db2 object exceeds, for example, 80% of the data set space.

Requirements

PTF UI91411 for APAR PH51040 must be installed on the 5.5.0 release of OMEGAMON for Db2. This PTF also requires the Configuration Manager (and PARMGEN) PTF UJ92594 / APAR OA64598 which enables the proper validation of the parameters.

To enable the Event Exception monitoring in OMEGAMON for Db2 you first need to enable the Event processing (set KD2_OMPE_DB2_EVENT parameter to Y) and then specify parameter KD2_OMPE_DSN_EXTENT to Y. To specify the threshold value that will process the written IFCID 258 records, configuration parameter KD2_OMPE_EXTENT_THOLD is used.

The new functionality allows you to specify a percentage value now, which is more comfortable than specifying an absolute number of extents. Please note that the existing values of the parameter (absolute values) are still supported for backward compatibility.

Monitoring data set extent events in the Enhanced 3270 UI

To access the Events collected in the enhanced 3270 UI, on the main menu for in E3270 (single or Plex view), specify “E” to enter the Events monitoring workspace:

A new option “DSextent” was added to the very first Events workspace, besides the existing Timeout and Deadlock events:

Specify "Y" for DSextent and specify the time range for which you want to see the respective events:

Note: A maximum of 500 events are kept in history (event exception log file), so make sure you do specify a proper threshold in the configuration step that is not too high or too low.

For partition-by-growth table spaces we calculate actual partitions in use. In above example 18% of maximum partitions are currently in use.

For other types of tables paces the current data set space in use is calculated based on IFCID 258 data.

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Using threshold highlighting

Along with the new functionality, a product provided threshold for the percentage value is delivered.

A warning highlight (in yellow) is set when space usage is between 50 and 74 percent.

A critical highlight (in red) is set when space usage is more than 74 percent.

Be aware that these are product provided default threshold values. They should likely be be modified as per monitoring requirements. The modification should be done in member RKANPARU(KDPTHRSH).

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