Statements and parameters for ASCHPMxx

CLASSADD

The CLASSADD statement identifies a class of transaction initiators to the APPC/MVS transaction scheduler configuration. The CLASSADD contains the class name, the maximum and minimum number of transaction initiators to assign to the class, the response time goal, and the message limit. Each class for the APPC transaction scheduler must be defined with a CLASSADD statement.

At least one class definition is required for work that is assigned to the APPC/MVS transaction scheduler. If work comes in for a class that is not defined by a CLASSADD statement, the work is rejected.

You can modify a class by overriding a previous CLASSADD statement with another CLASSADD statement that names the existing class and changes the parameter values to be modified. When more than one CLASSADD statement exists for the same class, the most recently processed statement is in effect.

CLASSNAME(classname)

A required parameter that specifies the name of a class of transaction initiators. When a class name is specified in a TP profile, the APPC/MVS transaction scheduler assigns the TP to run in that class. If no class name is specified in a TP profile, the default class from the OPTIONS statement is used. If the class in the TP profile does not match any class name that is specified on a CLASSNAME statement and there is no default class, the TP cannot run.

SRM uses the class of transaction initiators as one of the items to determine dispatching priority.

Value range: A 1- to 8-byte character string of uppercase letters A through Z, numerals 0-9, and national characters (@, $, #). The range must begin with an alphabetic or national character.

Default: None

MAX(nnnnn)

An optional parameter that specifies the maximum number of transaction initiators that are allowed for a particular class of transaction initiators. After this limit is reached, no new address spaces are created and incoming requests are queued to wait until existing initiator address spaces become available. The value must exceed the maximum number of address spaces that are allowed by your installation. Be aware of competing products on the system that will also require address spaces.

If this value is too high, system resources that might be needed elsewhere are not available. If this value is set too low, transaction programs will wait on the queue until an existing initiator becomes available, jeopardizing the response time goal for the class. To optimize performance while still meeting resource goals, specify a value that is a percentage of the total number of possible transactions that are running in the class at a time. You can determine the exact percentage after considering the number of transaction initiators available for all the classes, and experimenting with various values until one meets performance requirements.

Value range: 1 - 64000

Default: 1

MIN(nnnnn)

An optional parameter that specifies the minimum number of transaction initiators that are brought up for a particular class of transaction initiators when the ASCH address space starts or changes dynamically with a SET command. If the MIN value exceeds the MAX value, the MIN value is set to the MAX value. The number of transaction initiators available in each class never goes below the MIN number. In setting this value, consider the type of transaction programs that will run in this class. You might want certain classes to have initiators that are always available, while others classes require fewer initiators.

If this value is set too high, system resources that might be needed elsewhere are left idle. If this value is too small, the scheduler might waste time and resources when creating and deleting transaction initiators. To optimize performance while still meeting resource goals, specify a value that is a percentage of the total number of possible transactions that are running in the class at a time. You can determine the exact percentage after considering the number of transaction initiators available for all the classes, and experimenting with various values until one meets performance requirements.

Value range: 0 - 64000

Default: 0

MSGLIMIT(nnnnn)

An optional parameter that, for all transaction programs running within the class, specifies the maximum number of messages that are written to the message log each time the transaction program runs. For more information about selecting an MSGLIMIT value, see the topic about logging transaction program processing in z/OS MVS Planning: APPC/MVS Management.

Value range: 1-15000 messages

Default: 500 messages

RESPGOAL(nnnnnnnn)

An optional parameter that specifies the response time goal for transaction programs that are executing within this class. The RESPGOAL value is the total time in seconds that an installation wants to allow for queuing and running a transaction in this class. To meet this goal, APPC/MVS can create additional transaction initiators for the class until the MAX value is reached.

To determine how well response time is being met, you can see transaction run times in the RMF™ Monitor I Workload Activity Report. transaction program run times can also be obtained via SMF reports.

The response time goal should be set by determining the average run time for transactions in a class and adding in an allowable queue delay time. The additional queue delay time provides the APPC transaction scheduler some control to attempt to optimize overall system overhead that is associated with creating and deleting transaction initiators.

Value range: 0.000001 - 31536000 seconds (365 days)

Default: 1

CLASSDEL

The CLASSDEL statement deletes a class of transaction initiators from the APPC/MVS transaction scheduler configuration. One CLASSDEL statement must be specified for each class of transaction initiators that is to be deleted.

CLASSNAME(classname)

A required parameter that specifies the name of an existing class of transaction initiators to be deleted.

The value range is a 1- to 8-byte character string of uppercase letters A through Z, numerals 0-9, national characters (@,$,#) and must begin with an alphabetic or national character.

Default: There is no default. A value must be specified.

WORKQ({PURGE|DRAIN})

A parameter that specifies whether a class work queue is to be drained or purged when the work class is deleted.

DRAIN: When you specify DRAIN on the WORKQ keyword, new work for the class is rejected; however, work that was assigned before the class was deleted is allowed to finish.
PURGE: When you specify PURGE on the WORKQ keyword, all work that is queued up for this class is rejected. An error message is returned to the issuers of the ALLOCATE request. However, work that is running is allowed to complete its processing.

Default: DRAIN

OPTIONS

The OPTIONS statement defines class options for the APPC transaction scheduler. Options include naming a default class to be used when a transaction program profile does not specify a class, and naming a subsystem to which transaction initiators are assigned.

You can modify these options by overriding a previous OPTIONS statement with another OPTIONS statement that changes parameter values to be modified. When more than one OPTIONS statement exists, the most recently processed parameter values are in effect.

DEFAULT(classname)

An optional parameter that specifies the default class of transaction initiators in which to run a transaction program when a class name is not specified in a transaction program profile.

If the transaction program profile does not specify a class name, and there is no default that is defined by this parameter, the request to run the transaction program is denied. If the DEFAULT parameter names a class that does not exist, an error message is displayed on the console.

To delete the previously specified default class, specify a null value for DEFAULT. The format for a null value is: DEFAULT()

Value range: Null or a 1- to 8-byte character string of uppercase letters A through Z, numerals 0-9, national characters (@, $, #) and must begin with an alphabetic or national character.

Default: None

SUBSYS(ssname)

An optional parameter that specifies the name of the subsystem under which all newly created APPC/MVS transaction initiators are started. This value applies to all defined classes of transaction initiators.

If you specify a JES subsystem, it must be defined to the system in an IEFSSNxx parmlib member.

When running APPC transaction programs that do not require JES services (such as SYSOUT processing), you can specify SUBSYS(MSTR). Also, if you are using a version of JES2 lower than 4.2.0, or a version of JES3 lower than 4.2.1., specify SUBSYS(MSTR) because APPC/MVS does not support JES services at these lower levels.

To delete the previously specified subsystem, specify a null value for SUBSYS. The format for a null value is: SUBSYS()

Value range: Null or 1- to 4-characters. The name must begin with an alphabetic or national character (@, $, #). The remaining characters, if any, can be alphanumeric or national.

Default: The primary JES subsystem.

TPDEFAULT

The TPDEFAULT statement supplies default information when it is missing from the scheduler JCL section of a TP profile that is scheduled by the APPC/MVS transaction scheduler. Defaults include the region size of the transaction program, time limit for running the transaction program, the level of messages to appear in the message log, and the output class for TP SYSOUT.

You can modify defaults by overriding a previous TPDEFAULT statement with another TPDEFAULT that changes parameter values to be modified. When more than one TPDEFAULT statement exists, the most recently processed parameter values are in effect.

MSGLEVEL(1,n)

An optional parameter that specifies the level of messages that are generated for TPs that do not specify MSGLEVEL in the form MSGLEVEL(1,n). This MSGLEVEL is similar to the JCL MSGLEVEL parameter, but it behaves differently in APPC/MVS. TP profile JCL is processed in two phases, which are reflected in the two subparameters (1,n).

The first subparameter 1 controls the listing of statements, procedure statements, and substitution JCL messages, which occur during TP profile add and modify processing. These statements and messages are listed in the APPC administration utility output file (SYSPRINT). The value for this parameter must be 1.

The second subparameter n controls the generation of messages that occur when the TP profile is accessed to run a TP. If you specify 0 for this subparameter, allocation and termination messages are generated only if the TP abnormally terminates. If you specify 1 for this subparameter, allocation/termination messages are always generated.

This subparameter works with the KEEP_MESSAGE_LOG parameter of the TP profile. Messages are generated according to the MSGLEVEL parameters and are written to the TP message log according to the KEEP_MESSAGE_LOG parameter. If the value of KEEP_MESSAGE_LOG is error and MSGLEVEL is (1,0) or (1,1), messages are written to the logon error. If the value of KEEP_MESSAGE_LOG is always and MSGLEVEL is (1,1), messages are always written to the TP message log. (When KEEP_MESSAGE_LOG is always and MSGLEVEL is (1,0), allocation and termination messages are generated only when the TP abnormally terminates.) If the value of KEEP_MESSAGE_LOG is never, no messages are written regardless of the value of MSGLEVEL.

The value for the first subparameter must be 1, which results in the following format:

MSGLEVEL=(1,messages)

Value range: The value range for messages is as follows:

(0) Allocation/termination messages are generated only if the TP abnormally terminates.
(1) Allocation/termination messages are always generated.

Default: MSGLEVEL(1,0)

OUTCLASS(n)

An optional parameter that specifies the default value for MSGCLASS when MSGCLASS is not specified on the JOB statement in the TP profile.

Note: In APPC/MVS, MSGCLASS does not assign the output class for a job log (TP message log). However, MSGCLASS can affect SYSOUT processing. For more information, see the MSGCLASS keyword in z/OS MVS JCL Reference.

Value range: A - Z, 0 - 9.

Default: A

REGION({nnnnK|nnnnM})

An optional parameter that specifies the default region size that is assigned to TP profiles that do not specify a region size.

Value range: 0 K - 9999 K or 0 M - 2047 M

Default: 2 M

TIME(NOLIMIT|mmmm[,ss])

An optional parameter that specifies the default step time limit that is assigned to TPs that do not specify a time limit. The time limit is of the following format:

TIME(minutes,seconds) or TIME(NOLIMIT) or TIME(minutes) or
TIME(,seconds)

When time is in minutes only, do not include the comma. When time is in seconds only, include the comma before the seconds. TIME(NOLIMIT) is equivalent to TIME(1440).

Value range: The value range is as follows:

Minutes: 1 - 1440
Seconds: 1 - 59
NOLIMIT

Default: TIME(1440)