HP 3000 Manuals HP 3000 Manuals
Introducing the Threshold Manager
by Kendall Sutton
Commercial Systems Division
Overview
Threshold Manager is a new system manager utility shipping with FOS for
MPE/iX Release 5.0. This utility alerts the system manager when certain
internal operating system resources reach critical levels of utilization
that can lead to a system abort. It can be configured to print console
messages and automatically turn off a job and session logon when a
specific level of utilization is reached.
Internal operating system resources are not unlimited. In some cases,
when resources are exhausted, a system abort can occur. Threshold
Manager allows a threshold (a utilization percentage) to be set against
specific operating system resources. These resources are typically
system tables, which contain a limited number of entries to be allocated.
When that utilization level is reached (for example 90% of the table
entries are allocated and only 10% remain), Threshold Manager provides
notification of that situation. Optionally, it can be configured to
provide notification as well as to take action to disallow jobs and
session logons. This is similar to the action that occurs when the
system is critically low on transient disk space.
Although Threshold Manager can be configured to automatically turn off a
job and session logon when a specific level of utilization is reached, a
system manager can still logon using the hipri parameter. When the
threshold danger has passed, the ability to logon to a session or job is
re-enabled.
By alerting the system manager that a resource is at a dangerously high
utilization level, actions can be taken to reduce the demands on the
system. For example, low priority users could be logged off or
non-critical jobs could be aborted. These kinds of actions can help
prevent system aborts that result from the depletion of critical system
resources.
Configuration
Different systems will utilize resources at different levels. A
Threshold Manager configuration appropriate for one system may not be
appropriate for another. Threshold Manager comes with a default
configuration that can be customized, based on experience, for a
particular system.
The default state for Threshold Manager at system boot time is disabled;
therefore, no monitoring of system resources is performed at this time.
In order to enable the manager, run the program THMGR.PUB.SYS. At the
prompt enter the ENABLEMANAGER command. The default configuration will
then be in effect.
In order to start Threshold Manager automatically during the boot
process, you should create a job stream file similar to the one below and
put the stream command for it in the SYSSTART file.
!JOB THRESHMG,OPERATOR/PASSWD.SYS/PASSWD
!RUN THMGR.PUB.SYS;INFO="ENABLEMANAGER"
!EOJ
For complete information on running and configuring Threshold Manager,
see the Using Threshold Manager section in Performing System Manager
Tasks (32650-90004).