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

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

navigate to their event workspaces with actual data. The graphic view, the

graphical equivalent of the Navigator, which shows alerts but no data, affects

client memory but not the Tivoli Enterprise Portal Server.

5.4 Tuning situations

Situation is the mechanism in IBM Tivoli OMEGAMON XE that generates an

alert when an out-of-norm condition occurs. The situation evaluates system

attributes and decides whether a potential problem condition is occurring. The

situations are evaluated on a regular interval. This section covers analyzing

situation processing and reducing its processing requirements.

5.4.1 Situation processing

Situations are a mechanism in IBM Tivoli OMEGAMON XE that automatically

performs monitoring for you. Situations collect performance indicators and

subject them to conditional checking, which is associated with a threshold. When

the condition is true, the situation is raised or fires and an event is generated.

These state changes are passed to the Tivoli Enterprise Monitoring Server.

The frequency of state changes affects hub and remote Tivoli Enterprise

Monitoring Server capacity. It also affects storage requirements because these

events are saved in memory and written to disk. The sampling intervals

themselves affect Tivoli Enterprise Monitoring Server capacity.

Several important considerations for situation processing that can greatly affect

the performance of the IBM Tivoli OMEGAMON XE system are discussed here:

򐂰 Situation distribution

򐂰 Situation predicate processing

򐂰 Situation threshold and interval

򐂰 Situation synchronization

򐂰 Situation and policies

򐂰 Embedded situations

5.4.2 Situation distribution

All situations are in RKDSSITF, a VSAM file in z/OS-based Tivoli Enterprise

Monitoring Server, or the QA1CSITF file on a distributed-based Tivoli Enterprise

Monitoring Server. This file shows every user-defined situation, including those

that are not distributed or are distributed but not started.

Chapter 5. IBM Tivoli OMEGAMON XE performance optimization 163

Predefined situations are in the TKANDATV(KxxSITx) file. It shows where the

situations originated when you registered or seeded the Tivoli Enterprise

Monitoring Server.

Situations can be autostarted or manually started. Situations assigned to

managed systems, autostarted or not, are distributed to their Tivoli Enterprise

Monitoring Agents at Tivoli Enterprise Monitoring Server startup time. This

requires processing and affects Tivoli Enterprise Monitoring Server startup time.

If a Managed System List (MSL) is updated, then all the situations that use the

MSL are redistributed to all managed systems in the list that require processing

at the Tivoli Enterprise Monitoring Server and the affected Tivoli Enterprise

Monitoring Agents. For example, when a new CICS region comes online for the

first time, the *CICS Managed System List is updated. If the default distribution

assignments have not been modified, this will cause all 272 product-provided

CICS situations to be redistributed to all Tivoli Enterprise Monitoring Agents that

are monitoring CICS regions. Therefore, you should regularly remove the

distribution assignment from any situation that is not autostarted or manually

started.

When you copy predefined situations and give them site-specific names to

protect them from changes that IBM Tivoli might make in future releases, make

sure you disable the original situation by turning off autostart and removing its

distribution list. This is critical for many distributed products that distribute all of

their predefined situations.

At Tivoli Enterprise Monitoring Server startup, autostarted situations must be

distributed to all of their agents. Note that subnodes are not unique distributions.

Because situations also use CPU at the agents, Tivoli Enterprise Monitoring

Servers that have agents installed on them are also affected.

To stop a situation from autostarting, open the situation editor and select the

Condition tab, which is the default. If it is checked, remove the check mark from

the Run as startup specification as shown in Figure 5-10 on page 164. This

does not stop a situation that is currently started as it will not take effect until the

next startup of the affected Tivoli Enterprise Monitoring Agent. If required,

manually stop the situations.

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

Figure 5-10 Modify situation’s Run at startup specification