Configuring SQTHRESHOLD settings

SQTHRESHOLD settings are specified with SQTHRESHOLD statement keywords. Define a logical partition and an action (STOP is the only supported action) with SQTHRESHOLD statement keywords in the IMS Queue Control Facility extensions PROCLIB member.

About this task

SQTHRESHOLD has the following characteristics:

SQTHRESHOLD sets a threshold for the primary message queue structure. The threshold is expressed as a percentage of all entries or elements allocated. The threshold represents level of total primary message queue structure usage as an accumulation of all IMS entities queue activity in the shared queue group.
SQTHRESHOLD targets total primary message queue structure usage, not specific queue usage in the primary message queue structure. Total primary message queue structure usage is defined as the sum of primary message queue structure usage by all specific IMS processes (entities) in the shared queue group.
Only one SQTHRESHOLD statement is allowed, which means only one partition can be defined. A partition is a boundary that is expressed as a percentage of all entries or elements allocated to the primary message queue structure.
STOP is the only supported action that is triggered when the boundary is crossed.
SQTHRESHOLD statement does not support the TYPE= parameter. All IMS entities, which include APPL (dependent region applications), APPC (LU 6.2/APPC applications), and OTMA (OTMA applications) are analyzed and stopped.

SQTHRESHOLD uses two types of analysis to identify excessive total primary message queue structure usage:

Entry analysis

Determine if the total entry usage meets the SQTHRESHOLD PERCENT specification.
If met, implement specified action against the identified IMS entity and all IMS ensuing entities.

Element analysis

Determine if the total element usage meets the SQTHRESHOLD PERCENT specification.
If met, implement specified action against the identified IMS entity and all IMS ensuing entities.

Procedure

Follow these steps to configure SQTHRESHOLD settings. You can also refer to SQTHRESHOLD setting examples for examples of SQTHRESHOLD control statements.

Specify the PERCENT= keyword and its parameter on the SQTHRESHOLD statement.

The value for PERCENT specifies how much of the total queue will be looked at for analysis. The value determines the level of primary message queue structure usage. The value is applied to both entry analysis (entry usage) and element analysis (element usage).

The value can be in the range of 00 - 99.
Specify the ACTION= keyword and its parameter.

The only value supported for the ACTION= keyword is STOP. The action STOP is applied to all APPL, APPC, and OTMA processes.
When you have completed specifying SQTHRESHOLD statement, ensure that the QCF Queue Space Notification exit is activated. If it is not activated, configure and activate it by referring to 9. Enabling the QCF Queue Space Notification exit.