Parameters

NAME=

Specifies the name of a JES3 main. The name can be 1 to 8 characters. The name should match the purpose of the main, or at least the hardware it is using. You also use this name in operator commands and in the JES3 CLASS, DEVICE, GROUP, MSGROUTE, and SETACC initialization statements to refer to the main. It must be the first or second parameter on the statement.

Do not use names or abbreviations of operator commands such as ‘CONTROL’, or message destination class names. Do not use the terms 'short,' 's,' 'all,' or 'ALL' as names of mains.

Ensure that the name you specify matches the name you specify on the SYSNAME parameter in the IEASYSxx member of the MVS™ SYS1.PARMLIB data set that is used to IPL the system. If the names do not match, JES3 initialization will fail on that system. See z/OS MVS Initialization and Tuning Guide for additional information about the IEASYSxx member of the MVS SYS1.PARMLIB data set.

SYSTEM=

Specifies that JES3 is running on this main. You do not need to code this parameter.

FIXPAGE=

Specifies the number of pages of USAM protected data buffers (PBUFs) that JES3 is to fix in storage during JES3 initialization.

If fixedpages is less than csapages (specified on the PRTPAGE parameter), JES3 fixes the specified number of pages in ECSA only.
If fixedpages is greater than csapages, JES3 fixes all PBUF pages in ECSA. If you specify auxpages on the PRTPAGE parameter, JES3 determines the remaining number of pages to be fixed (fixedpages – csapages) and fixes that number of pages in the JES3 auxiliary address space.

ID=

Specifies a message prefix (1 to 8 characters) for every message received from this JES3 main and logged on the MDEST console (determined by the MDEST parameter). This prefix will precede the R prefix which automatically identifies every message that is received.

To suppress the automatic R prefix, code a pound sign (#) as the last character of the prefix. For example, ID=SYS2 provides SYS2 R=message; but ID=SYS2# provides SYS2=message.

JESMSGLMT=

Specifies how you want JES3 to control the issuing of messages by establishing message limits.

WTO_limit

Specifies the maximum number (0–99999999) of messages that can be issued within a period of time defined by the "Interval" subparameter before JES3 issues message IAT6850 to prompt operator action. IAT6850 indicates both the jobname and system on which the job is running.

This message is primarily intended for automation processing.

If no value or 0 (the default) is specified, then no monitoring of JES3 issuing messages takes place.

Interval

Specifies the period of time (0–32767 seconds) to which the WTO limit subparameter applies.

You specify "0" to indicate that message will be issued every time the WTO limit is reached, regardless of the time it takes to arrive at that limit.

The actual interval value used by the system is calculated using the minimum resolution of the first word of the STCK instruction value (1.048576 seconds) and rounded up or down to the nearest integer.

MDEST=

Specifies the routing information for messages that are about this main. This value may be specified as a JES3 destination class selected from the range M1 to M32, or as an MVS routing code.

If a routing code is used, nnn specifies a decimal number from 1 through 28, or 41 through 128. IBM® reserves routing codes 29 through 40 for it's use. If these route codes are specified, they will be ignored.

If a JES3 destination class is specified, the MVS routing code equivalent of the destination class is used to route the messages. Seez/OS JES3 Initialization and Tuning Guide for a summary of the JES3 destination classes and their routing code equivalents.

PRTPAGE=

Specifies the number of pages of storage that JES3 may use as USAM protected data buffers (PBUFs). For more information about JES3AUX address space and defining buffers, see z/OS JES3 Initialization and Tuning Guide.

csapages

Specifies the number of pages of ECSA that you want JES3 to use.

auxpages

Specifies the number of pages in the JES3 auxiliary address space that you want JES3 to use. The total number of pages (csapages + auxpages) that you can specify must be between 16 and 16,383 or 16 and 32,767 inclusive, depending on the number of buffers per page.

The maximum number of pages is 32,767 for systems with one buffer per page (a buffer size greater than 2036 bytes) or 16,383 for systems with two buffers per page (a buffer size of 2036 or less). You specify the size of buffers on the BUFSIZE parameter of the BUFFER initialization statement.

Note: Specifying more buffers than are appropriate for the available amount of central storage can degrade performance. A value of 16,383 consumes approximately 64 megabytes of virtual storage (some in ECSA and some in the JES3 auxiliary address space as defined on the csapages and auxpages parameters). Specifying a maximum of 32,767 consumes approximately 128 megabytes of virtual storage (some in ECSA and some in the JES3 auxiliary address space as defined on the csapages and auxpages parameters).

If you do not want to allocate JES3 auxiliary storage, specify 0 as the auxpages value.

JES3 uses the following defaults if you do not specify values for the PRTPAGE parameter or both the csapages and auxpages parameters:

csapages:: 16 times the number of spool data sets or 512, whichever is smaller.
auxpages:: 0

If only one subparameter is specified, the other subparameter defaults to zero.

SELECT=

Specifies the name of the job selection mode to be initially assigned to this main. The scheduling controls associated with this job selection mode should be appropriate for the main being defined by this MAINPROC statement. The selmode must match the NAME parameter on a SELECT initialization statement (except if the default JS3BATCH is used).

SPART=

Specifies the spool partition that JES3 is to use for jobs that execute on the main defined by this statement. The partition name must match a partition name specified on an SPART statement. To specify the default spool partition, omit the SPART parameter.

If you specify an undefined partition name, JES3 uses the default partition.

A partition name specified on a //*MAIN JES3 control statement or on a CLASS statement can override the partition name specified by this parameter. For a discussion of the order of overrides and when they occur, see “Determining the Order of Spool Partition Overrides” and “How the User Can Request A Spool Partition” in z/OS JES3 Initialization and Tuning Guide .

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

TRKGRPS=

Specifies the number of track groups (as defined by the GRPSZ parameter on the BUFFER or SPART statement) JES3 is to allocate to jobs that execute on this main. For guidelines on how to determine the appropriate value for the TRKGRPS parameter for your installation, see “Determining Track Group Allocation Sizes” in z/OS JES3 Initialization and Tuning Guide.

prigrps: Specifies the number of track groups to be initially allocated to jobs that execute on this main. The specified value may be 1 through 9.
secgrps: Specifies the number of track groups to be allocated to jobs that execute on this main subsequent to their primary allocation. JES3 allocates the specified amount of spool space after the job uses up its initial allocation, and again (for an unlimited number of times) when the job uses up each secondary allocation and requests more spool space. The specified value may be 1 through 9.

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

USRPAGE=

Specifies the number of 4K pages for each open SYSOUT data set. The USRPAGE parameter indicates pages of user address space for SYSOUT buffers. These pages are used as required and released when they are no longer required. Specify a 1- or 2-digit number from 1 to 20.

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