190 IBM Tivoli OMEGAMON XE V3.1 – Deep Dive on z/OS
additional fields in these groups. As stated earlier, when you are monitoring with
all of the product-provided situations, the overhead is the same as in the previous
version. You can have less overhead if you do not activate all of the situations for
all of the control regions.
An additional refresh on the Tivoli Enterprise Portal also drives data collection.
Therefore, the potential for less overhead is in discovering regions for reactive
monitoring without enabling situations. Regions that need less proactive
monitoring can have fewer active situations, which means less data collection
and overhead. In V3.1.0, not using *IMS and using MSLs for production or test
can reduce data collection overhead.
5.5.5 IBM Tivoli OMEGAMON XE for DB2 on z/OS
This section discusses the following topics on tuning IBM Tivoli OMEGAMON XE
for DB2 on z/OS:
The probes that collect the data for the various report containers can be
invoked less frequently. The interval is controlled by the KDPCNFG member
of RKANPAR. The interval is the number of seconds between sampling
intervals. If the interval value is zero, then this component will not execute.
Collection can be disabled temporarily without recycling the Tivoli Enterprise
Monitoring Server to aid in problem or overhead determination. The modify
commands in Example 5-13 stop and restart all the collectors. These
commands also make the changes in KDPCNFG effective.
Example 5-13 Commands to stop DB2 collector
F stcname,DPDC STOP IRLM(BRLM)
F stcname,DPDC STOP DB2(D411)
F stcname,DPDC START IRLM(BRLM)
F stcname,DPDC START DB2(D411)
DB2 object analysis overhead
If you have a lot of DB2 objects and Object analysis is enabled in the
OMEGAMON II for DB2 component, you may see high overhead in KFACOM.
This module creates indexes in core databases created from data that is
moved from the remote Tivoli Enterprise Monitoring Servers to the hub Tivoli
Enterprise Monitoring Server using XCF. You may also see high storage
usage in extended storage subpool size (145-160). Use the SQL code similar
to Example 5-8 on page 157 to disable UADVISOR_KDP_VLOBJECTS. Just
change all of its references to the DASD situation to the one listed above.