Parameters

NAME=

Specifies the 1- to 8-character name of a job class group. A job class is assigned to this job-class group by placing this group name on its CLASS statement. The NAME parameter must be the first parameter on the GROUP statement. The first character of this name must be alphabetic (MVS™ restriction).

MODE=

Specifies whether the initiators managed by this group are WLM managed or JES3 managed.

WLM: Specifies that jobs in this job class group are to run under Workload Management initiators, that is, WLM-managed initiators.
JES: Specifies that jobs in this job class group are to run under JES3-managed initiators.

See z/OS JES3 Initialization and Tuning Guide for details on WLM-managed and JES3-managed initiators.

EXRESC=

Defines the execution resources, such as initiators, processors, and devices, which you want assigned to this job class group. Jobs in this group use devices assigned to the group to satisfy requests for mountable volumes. An EXRESC parameter must be specified for each main on which this group may be scheduled.

The EXRESC parameter must still be specified even if MODE=WLM, because JES3 still needs to know which system's jobs in this group are allowed to execute. If a particular system name does not appear in the EXRESC parameter, jobs in that group will not be allowed to run on that system.

*ALL

Identifies that you want the parameters that you are specifying to apply to all systems in the JESPLEX. By specifying *ALL, instead of listing the individual systems, you make it easier to add a system to your JESPLEX. In this case, you do not have to update your GROUP initialization statements when you add a MAINPROC statement.

procname

Identifies the main associated with the execution resources. The main name must match the NAME parameter on a MAINPROC statement.

If *ALL is specified as the main name, the parameters that you specify are applied to all main processors defined through MAINPROC initialization statements. By specifying *ALL instead of listing the individual systems, you make it easier to add a system to your SYSPLEX. For example, if you add a new MAINPROC statement for system SYXYZ, and you specify *ALL in the EXRESC parameters of your GROUP statements, the new system will automatically be included in each of the group definitions.

You cannot specify *ALL and then list specific system names, and vice versa.

initcnt

The initcnt value indicates the dedicated initiator count. This subparameter defines the number of initiators you want assigned exclusively to this group. When scheduling jobs from this group, only the dedicated initiators will be used; therefore, this count defines the maximum number of jobs of this group that can be concurrently scheduled to the specified main. Dedicated initiators that become idle will not be used for scheduling any other job class group. The value of initcnt must be less than the value of the MAXUSER parameter in the IEASYSxx member of SYS1.PARMLIB that will be used for the IPL. The MAXUSER parameter is discussed in z/OS MVS Initialization and Tuning Reference. The initiator identifier is the same as the group name. Each initiator started for MVS processors is identified by the GROUP name. For example, if the dedicated initiator count for GROUP=ABC is 2, then two initiators would be started with identifier ABC. The dedicated initiator count for the default group JS3BATCH is 2. The initnum count parameter on the SELECT initialization statement overrides the initcnt parameter. See Parameters for additional information.

Note: The initiator count is not used when you specify MODE=WLM. If you switch to MODE=JES by using the *MODIFY,G command, the value that you specified for the initiator count is used.

storsize

JES3 no longer supports this subparameter. It has been retained so that initialization streams will not have to be changed. If you plan to code any of the following positional subparameters, code a comma (,) to represent this subparameter.

alopt

Determines when the execution resources are to be allocated to the group. Four options are available: DEMAND, DYNAMIC, IPL, or MANUAL.

DEMAND indicates that initiators are to be allocated to satisfy the requirements of selectable jobs in this group up to the number specified by initcnt. DEMAND is the default allocation option.

DYNAMIC indicates that the named execution resources are to be allocated when the first job of this class is eligible for scheduling on a main.

IPL indicates that the execution resources are to be allocated whenever IPL occurs on the main associated with this group. If subsequent reallocation is necessary, it must be done manually.

MANUAL specifies that the execution resources are to be allocated whenever the operator enters the command *F,G,main,G,grp,ON to turn on the group.

The default allocation option is DEMAND.

See Parameters for additional information.

Note: The initiator allocation option is not used when you specify MODE=WLM on the GROUP initialization statement. If you switch to MODE=JES by using the *MODIFY,G command, the value you specified for the initiator allocation option is used.

unalopt

Determines when the execution resources are to be released from the group. Three options are available: DEMAND, DYNAMIC, or MANUAL.

DEMAND indicates that the initiators are to be deallocated when the number of selectable jobs for this group is less than the number of allocated initiators minus the number of initiators that are currently active. DEMAND is the default deallocation option.

DYNAMIC indicates that all execution resources are to be released when no selectable jobs exist for this group.

MANUAL indicates that all execution resources are not to be released until the operator disables the job class group by issuing the *F,G,main,G,grp,OFF command. MANUAL is the deallocation option for the default group JS3BATCH.

For all groups except the defaulted groupname JS3BATCH, the default deallocation option is DEMAND.

SELECT (Job Selection Mode) further explains how JS3BATCH becomes the defaulted groupname.

Note: The initiator unallocation option is not used when you specify MODE=WLM. If you switch to MODE=JES by using the *MODIFY,G command, the value you specified for the initiator unallocation option is used.

storopt

devopt

Indicates those devices on the specific main (procname) which are dedicated for use by jobs in this group for volume mounting (this is device fencing). This parameter specifies how the devices in this device fence can be allocated. The options are ANY and GROUP.

ANY specifies that jobs are to be able to allocate any devices that are accessible from the main. Note that allocation will attempt to get dedicated (fenced) devices before using devices outside the fence.

GROUP indicates that jobs in this group may allocate requests requiring volume mounting only from devices dedicated to the group on the main. This allows device fencing exclusively because no nondedicated devices are to be used for volume mounting. GROUP is the default device allocation option.

devname,devcount ,devname,devcount

Identifies the device(s) to be dedicated. The subparameters may be repeated, in pairs as is necessary.

devname

Indicates the unit address of the device or the name of the device as specified in the NAMES parameter on the SETNAME statement. The devname subparameter should have devcount immediately following it.

devcount

Specifies how many of the indicated devices are to be dedicated; If a device number is specified for devname, the associated devcount specified must be 1.

/devnum or devnum

Specifies the device number (by 3-digit or 4-digit number). A slash (/) preceding the device number is not required. Device numbers can be specified by any of the following formats:

ddd
dddd
/ddd
/dddd

ddd and dddd represent the device numbers.

If devices are dedicated to a group on a main using the EXRESC parameter, the DEVPOOL parameter cannot be used. (Specification of dedicated devices in the EXRESC parameter allows device fencing for groups by main.)

BAR=

Specifies a job priority barrier. All jobs in this group that have a priority equal to or above this barrier must be scheduled before any attempt is made to schedule jobs below this barrier.

PRTY: Specifies that each priority level is to be treated as a barrier. Each job in a priority level must be scheduled before any job in any lower priority will be scheduled.
nn: Specifies a job priority number from 0 to 15.
16: No barrier is imposed on jobs in this group.

Note: When a value other than 16 is specified, the operator should be informed of its impact. For example, a held job equal to or above the barrier which is ‘awaiting selection of main’ will prevent any job below the barrier from being selected.

If you specify an invalid subparameter, JES3 uses the parameter default.

SeeStatement Summary for additional information.

DEF=

Indicates that this is the default group to be assigned to all job classes that have no GROUP parameter on the CLASS statement. Only one GROUP statement should specify the DEF=YES parameter; if you specify DEF=YES on multiple statements, the last such statement in the initialization stream defines the default class.

JS3BATCH is assigned as the default group with MODE=JES if DEF=YES is not specified on any GROUP statement in an initialization stream.

DEVPOOL=

Specifies that a pool of devices is to be dedicated to jobs in this group for volume mounting on all mains for which this group may be enabled. If the DEVPOOL parameter is specified, devices may not be dedicated in the EXRESC parameter.

The POOLNAMS parameter on the SETNAME statement, with appropriate XTYPE definitions on the DEVICE statement, may be used to define unique sets of devices with the shareability (physical attachment) desired for this group.

Note: Device fences apply to all jobs in a group whether the jobs are started tasks or batch jobs.

devopt

Specifies how JES3 is to allocate devices to jobs in this group.

ANY: Indicates that jobs in this group can use nondedicated devices and dedicated devices. JES3 always tries to allocate dedicated devices first. The default is ANY.
GROUP: Indicates that only devices dedicated to this group can be used for volume mounting.
Note: The pool of devices will not be dedicated until the group's execution resources have been allocated, as indicated by the alopt subparameter of the EXRESC parameter. Before that point, the devices can be used by jobs of any group. If you want the devices to be dedicated to this group at all times, specify IPL.

devname

devcount

Specifies how many of the indicated devices are to be dedicated; if a device number is specified for devname, the associated devcount specified must be 1.

/devnum or devnum

Specifies the device number (by 3-digit or 4-digit number). A slash (/) preceding the device number is not required. Device numbers can be specified by any of the following formats:

ddd
dddd
/ddd
/dddd

ddd and dddd represent the device numbers.

JSPAN=

Specifies the number of jobs in this group to be examined in selecting a job to be scheduled.

nnnnn: Indicates a decimal number from 1 to 65534.
ALL: Indicates that all the jobs in the group are to be examined.

See Parameters for additional information.