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

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

Historical data storage in monitoring agents

Avoid historical data storage at the hub Tivoli Enterprise Monitoring Server if

possible. Instead, store historical data at the agent or remote Tivoli Enterprise

Monitoring Server. If you store history in the PDS (Persistent Data Store) files, it

may be converted as above but it must be written to DASD. This can use cycles

to store and retrieve. Besides steady state cycles, large or multiple PDSs affect

Tivoli Enterprise Monitoring Server restart time, as they are read completely at

startup.

5.2.2 Tivoli Enterprise Monitoring Server hub platforms

When we move the hub Tivoli Enterprise Monitoring Server from z/OS, some of

the processing load is offloaded from the z/OS-based Tivoli Enterprise Monitoring

Server and executes on the distributed platform. This can help to reduce the

processing need for mission-critical z/OS systems to a dedicated server.

The following processing is offloaded from the z/OS-based Tivoli Enterprise

Monitoring Server:

򐂰 Situation state changes

򐂰 Situation evaluation

򐂰 Managing agents (heartbeats and distribution)

򐂰 Data conversions: ASCII-to-EBCDIC or EBCDIC-to-ASCII

򐂰 Historical data storage from remote agents

However, often the largest source of hub Tivoli Enterprise Monitoring Server

processing is code that must run on z/OS. But this code does not necessarily

have to run in the hub. Some of this overhead can be moved to other z/OS

images, while the remainder can stay on the same machine, even if the hub is

moved to a distributed platform. You can experience higher CPU in the hub Tivoli

Enterprise Monitoring Server than in other z/OS-based Tivoli Enterprise

Monitoring Servers. This may occur due to:

򐂰 Data movement and sorting

Moving large quantities of data can be a major source of processing,

especially if the data is sorted or merged. This overhead can usually be

moved to a remote Tivoli Enterprise Monitoring Server or tuned.

Note: Two PTFs exist, UA19870 (for Candle Management Server V350) and

UA19871 (for Candle Management Server V360), that significantly reduce the

processing requirements when accessing Persistent Data Store (PDS)

datasets.

Chapter 5. IBM Tivoli OMEGAMON XE performance optimization 147

򐂰 Tivoli Enterprise Monitoring Server resident data collectors

– OMEGAMON II for MVS component’s WLM probe

The OMEGAMON II for MVS component of IBM Tivoli OMEGAMON XE

for z/OS WLM probe must remain on an LPAR in a Tivoli Enterprise

Monitoring Server, which can be a hub or a remote. If OMEGAMON II for

MVS CUA users have auto-update turned on, the number of users and the

auto-update interval may cause more processing on one LPAR, such as

the hub, than another.

– Hub Tivoli Enterprise Monitoring Server probes

Any products executing within a Tivoli Enterprise Monitoring Server such

as IBM Tivoli OMEGAMON XE for z/OS cannot be moved. You can still

have a remote Tivoli Enterprise Monitoring Server on the z/OS image.

Higher CPU usage by these functions on the hub Tivoli Enterprise

Monitoring Server may be related to the number of subsystems or the

volume of their workload.

– Sysplex proxy

If you have IBM Tivoli OMEGAMON XE for z/OS, it is likely that the sysplex

proxy data consolidation function has defaulted to running in the hub Tivoli

Enterprise Monitoring Server. This is a high-processing requirement

function and can be relocated easily. Simply configure the hub Tivoli

Enterprise Monitoring Server as not eligible for the sysplex proxy, which

will offload cycles from the hub Tivoli Enterprise Monitoring Server. This is

typically not done because the first Tivoli Enterprise Monitoring Server

defined is the hub Tivoli Enterprise Monitoring Server and, by default, the

configuration tool assigns the first Tivoli Enterprise Monitoring Server as

the sysplex proxy. You need to change this using IBM Configuration Tool

after the first remote Tivoli Enterprise Monitoring Server has been defined

to the hub. As Figure 5-5 on page 148 indicates, the hub Tivoli Enterprise

Monitoring Server has been excluded from performing the sysplex proxy

function.