IBM Tivoli OMEGAMON XE V3.1 Deep Dive on z/OS

166 IBM Tivoli OMEGAMON XE V3.1 – Deep Dive on z/OS

and processing. OMEGAMON for CICS on z/OS and OMEGAMON for DB2 PM /

PE on z/OS can be configured to selectively discover subsystems, which would

eliminate this issue. But that would also eliminate the ability to reactively view

data from unmonitored test systems. This may be desirable as it also eliminates

these subsystems and their associated navigator views, which may clutter your

view of your enterprise.

Both of these products can be configured to discover subsystems selectively,

which will reduce the processing requirements. This may be desirable because it

also keeps nodes off the Navigator Physical view. However, it would also

eliminate the ability to view data reactively from unmonitored test systems.

Many customers configure production regions and subsystems to a production

hub Tivoli Enterprise Monitoring Server and Tivoli Enterprise Portal Server, and

test regions or subsystems to a separate set. If you have systems for which you

do not want to perform exception analysis or collect historical data, you should

create user-defined distribution lists such as CICS_Production, which will have

the list of regions you want monitored.

5.4.3 Situation predicate processing

The situation contains predicates, in which the monitoring attributes to be

evaluated are specified. Different predicates generate different processing

requirements. It is important to understand how the predicates are processed to

analyze these predicates.

Predicates are processed sequentially from first to the last. If you have multiple

predicates in a situation, order them to eliminate as many rows as possible as

early as possible with the least expensive or most restrictive filter as the first

predicate.

Here are some predicate processing tips:

򐂰 Numeric attributes are processed more quickly than text attributes.

򐂰 String checking with substring (STR) is more efficient than the string scan

(SCAN), especially for long strings. If you know the exact location of the text

or characters to be evaluated, use a substring.

򐂰 A column function is evaluated at the Tivoli Enterprise Monitoring Server, so

all available rows will be sent back to Tivoli Enterprise Monitoring Server from

the agent, with high network usage, memory, and processing requirements as

a result. Try to avoid the predicates such as MAX, MIN, AVG on a column.