The statements for the ASCHPMxx parmlib member are listed below
and explained in more detail later.
- 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
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
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 one- to eight-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
- 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 should not exceed the maximum number of address
spaces allowed by your installation, and you should 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 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
may 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 may be needed elsewhere are left
idle. If this value is too small, the scheduler may waste time and
resources 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 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
- RESPGOAL(nnnnnnnn)
- An optional
parameter that specifies the response time goal for TPs executing
within this class. The RESPGOAL value is the total time in seconds
that an installation wants to allow for queueing 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. TP 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
associated with creating and deleting transaction initiators.
Value
range: 0.000001 - 31536000 seconds (365 days)
Default:
1
- MSGLIMIT(nnnnn)
- An optional
parameter that, for all TPs running within the class, specifies the
maximum number of messages written to the TP's message log each time
the TP runs. For more information about selecting a 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
- 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.
Value Range: A one- to eight-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. 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.
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 currently running is allowed to complete its processing.
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.
Value range: PURGE or DRAIN
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 TP 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 TP when a class name is not specified in a TP profile.
If the TP profile does not specify a class name, and there is
no default defined by this parameter, the request to run the TP 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 one- to eight-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 one- to four-characters. The name must begin with
an alphabetic or national character (@, $, #), and the remaining characters
(if any) can be alphanumeric or national.
Default:
Primary JES subsystem.
- TPDEFAULT
- The TPDEFAULT statement
supplies default information when it is missing from the scheduler
JCL section of a TP profile scheduled by the APPC/MVS transaction
scheduler. Defaults include the region size of the TP, time limit
for running the TP, 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.
- REGION({nnnnK|nnnnM})
- An optional
parameter that specifies the default region size assigned to TP profiles
that do not specify a region size.
Value range: 0K - 9999K
or 0M - 2047M
Default: 2M
- TIME(NOLIMIT|mmmm[,ss])
- An optional parameter
that specifies the default step time limit 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:
- minutes: 1 - 1440
- seconds: 1 - 59
- NOLIMIT
Default: TIME(1440)
- MSGLEVEL(1,n)
- An optional
parameter that specifies the level of messages 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 sub-parameters (1,n).
The first sub-parameter
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 sub-parameter n controls the generation of
messages that occur when the TP profile is accessed to run a TP. If
you specify 0 for this sub-parameter, allocation/termination messages
are generated only if the TP abnormally terminates. If you specify
1 for this sub-parameter, allocation/termination messages are always
generated.
This sub-parameter works in conjunction 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 log on error. If the value of KEEP_MESSAGE_LOG is always and
MSGLEVEL is (1,1), messages are always written to the TP message log.
(Note when KEEP_MESSAGE_LOG is always and MSGLEVEL is (1,0),
allocation/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 sub-parameter must be 1, which results in the
following format:
MSGLEVEL=(1,messages)
Value
range for messages: - (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 have an effect on SYSOUT processing.
For more information, see the MSGCLASS keyword in
z/OS MVS JCL Reference.
Value range:
A - Z, 0 - 9
Default: A