Change the CICS® system
attributes.
In the CICS Explorer, the Regions operations view provides
a functional equivalent to this command.
Syntax
Press the Clear key to clear the screen.
You can start this transaction in two ways:
- Type CEMT SET. The SYSTEM keyword is assumed
as the default, so you do not need to type it. The resulting display
lists the current status, similar to that obtained by using CEMT INQUIRE
SYSTEM. You can then tab to the highlighted or blank fields and overtype
them with the required values.
- Type CEMT SET followed by one or more attribute
settings that you want to change. For example, cemt set ag(value)
ma(value) resets the values for
priority aging and the maximum number of tasks allowed at any one
time in the CICS system.
Typing ? at the beginning of either the first or second
line gives a syntax prompt. Resetting the values takes effect immediately.
CEMT SET SYSTEM
.-------------------------.
V |
>>-CEMT SET SYSTEM----+---------------------+-+----------------><
+-AGING(value)--------+
+-AKP(value)----------+
+-+-DEBUG---+---------+
| '-NODEBUG-' |
+-DSALIMIT(value)-----+
+-DSRTPROGRAM(value)--+
+-DTRPROGRAM(value)---+
+-+-SYSDUMP---+-------+
| '-NOSYSDUMP-' |
+-EDSALIMIT(value)----+
+-+-FORCE---+---------+
| '-NOFORCE-' |
+-LOGDEFER(value)-----+
+-MAXTASKS(value)-----+
+-MROBATCH(value)-----+
+-+-CTLGALL----+------+
| +-CTLGMODIFY-+ |
| '-CTLGNONE---' |
+-PROGAUTOEXIT(value)-+
+-+-AUTOACTIVE---+----+
| '-AUTOINACTIVE-' |
+-RUNAWAY(value)------+
+-SCANDELAY(value)----+
'-TIME(value)---------'
Options
- AGING (value)
- Specifies
the time factor for CICS to
use in the priority aging algorithm to increment the priority of a
task. The value is expressed as
milliseconds per unit of priority
,
and must be in the range 0 - 65535. The priority aging factor is defined
initially by the PRTYAGE system initialization
parameter, in which the value represents the number of milliseconds
that must elapse before the priority of a waiting task can be adjusted
upward by 1. For more information about this parameter, see PRTYAGE .
- AKP (value)
- Specifies
the activity keypoint trigger value, which is the number of write
requests to the CICS system
log stream output buffer between the taking of keypoints. The value
can be zero, which turns activity keypointing off, or be in the range
50 - 65535. You cannot change this value if AKPFREQ=0 was specified
at system initialization.
- AUTOACTIVE
- Autoinstall for programs is active.
On first use, if a program, map set, or partition set is not defined,
the definition is created dynamically.
- AUTOINACTIVE
- Autoinstall is not active. If a
program is not defined, a PGMIDERR or transaction abend occurs when
it is referenced.
- CTLGALL
- All autoinstalled program definitions
are cataloged and restored on a warm or emergency restart.
- CTLGMODIFY
- Autoinstalled program definitions
are cataloged only if they are modified (for example, by a CEMT SET
PROGRAM command), so that the modified definitions are restored on
a warm or emergency restart.
- CTLGNONE
- No autoinstalled program definitions
are cataloged. They are autoinstalled again after a warm or emergency
restart.
- DEBUG
- Specifies
that CICS debugging profiles
can be used to select the programs that will run under the control
of a debugging tool. The following debugging tools use debugging profiles:
- Debug Tool, for compiled language application programs (programs
written in COBOL, PL/I, C, C++, and Assembler)
- Remote debugging tools (for compiled language application programs
and Java™ programs)
Other debugging mechanisms, for example the CICS Execution Diagnostic Facility (CEDF), do
not use debugging profiles. For more information about debugging
profiles, see Debugging profiles.
- DSALIMIT (value)
- Specifies
the maximum amount of storage, as a total number of bytes, within
which CICS can dynamically
allocate storage for the four individual DSAs that reside below 16
MB (below the line). For more information, see DSALIM system initialization parameter. If this parameter specifies a value
lower than the current limit, CICS might
not implement the new limit immediately, but attempts to do so over
time as dynamic storage is freed in the individual DSAs.
Note: Dynamic
changes to the DSA limit are cataloged in the
local catalog,
and override values specified in the system initialization table during
all forms of restart: initial, old, and warm. The cataloged value
is
not used if:
- You specify startup values as system initialization parameters
overrides (for example, in SYSIN).
- You re-initialize the CICS catalog
data sets.
Note: That while you are changing the DSA limits
dynamically is possible, it is recommended that you do not do so unless
you are addressing an urgent situation and are trying to avoid cycling
the region. While your change to the DSA limits might be successful
from the CICS perspective,
increasing the limits can cause other problems because the larger
DSA will no longer be contiguous. MVS™ allocates
storage both from high private growing down, and low private growing
up. Increasing the DSA limits dynamically will cause a new piece of
storage that is allocated by CICS in
the middle of the MVS private
storage area. Depending on the MVS use
of storage in this area, you might now be at increased risk of an
S878 or S80A abend as a result.
Similarly, decreasing the DSA
limits dynamically might indeed give back storage to MVS for use, but there is no certainty where
the storage given back will be, and it most likely will not be in
an area where MVS needed it.
Monitor CICS statistics regularly, and
proactively adjust DSA limits, and MXT limits.
- DSRTPROGRAM (value)
- Specifies
the name of the distributed routing program.
- DTRPROGRAM (value)
- Specifies
the name of the dynamic routing program.
- EDSALIMIT (value)
- Specifies
the maximum amount of storage, as a total number of bytes, within
which CICS can dynamically
allocate storage for the individual DSAs that reside above 16 MB but
below 2 GB (above the line). For more information, see EDSALIM system initialization parameter. If EDSALIMIT specifies
a value lower than the current limit, CICS might
not implement the new limit immediately, but attempts to do so over
time as dynamic storage is freed in the individual DSAs.
Note: Dynamic
changes to the EDSA limit are cataloged in the
local catalog,
and override values specified in the system initialization table during
all forms of restart: initial, old, and warm. The cataloged value
is
not used if:
- You specify startup values as system initialization parameters
overrides (for example, in SYSIN).
- You re-initialize the CICS catalog
data sets.
Note: That while you are changing the EDSA limits
dynamically is possible, it is recommended that you do not do so unless
you are addressing an urgent situation and are trying to avoid cycling
the region. While your change to the EDSA limits might be successful
from the CICS perspective,
increasing the limits can cause other problems because the larger
EDSA will no longer be contiguous. MVS allocates
storage both from high private growing down, and low private growing
up. Increasing the EDSA limits dynamically will cause a new piece
of storage that is allocated by CICS in
the middle of the MVS private
storage area. Depending on the MVS use
of storage in this area, you might now be at increased risk of an
S878 or S80A abend as a result.
Similarly, decreasing the EDSA
limits dynamically might indeed give back storage to MVS for use, but there is no certainty where
the storage given back will be, and it most likely will not be in
an area where MVS needed it.
Monitor CICS statistics regularly, and
proactively adjust EDSA limits, and MXT limits.
- FORCE
- Force all CICSAPI user application
programs to run under the QR TCB, even if they are defined with the
CONCURRENCY(THREADSAFE) attribute. The FORCE option
does not apply to certain programs, for example OPENAPI programs,
or C or C++ programs compiled with XPLINK. For details, see FORCEQR system initialization parameter.
- LOGDEFER (value)
- Specifies
the log deferral interval in milliseconds. This interval is the period
of time used by CICS Log Manager
to determine how long to delay a forced journal write request before
invoking the MVS system logger.
The value is in the range 0 - 65535. For more information, see LGDFINT system initialization parameter.
- MAXTASKS (value)
- Specifies
the maximum number of tasks, both active and suspended, allowed at
any one time in the CICS system.
The value must be in the range 10 - 2000.
Note: The value assigned
to MAXTASKS might be less than the requested value, because of CICS storage constraints. If this
occurs, the message CEILING REACHED is displayed when the request
is made.
- MROBATCH (value)
- Specifies
the number of MRO requests from connected regions that are batched
before this region is posted. The value must be in the range 1 - 255.
- NODEBUG
- Specifies
that you do not want to use CICS debugging
profiles to select the programs that will run under the control of
a debugging tool. The following debugging tools use debugging profiles:
- Debug Tool, for compiled language application programs (programs
written in COBOL, PL/I, C, C++, and Assembler)
- Remote debugging tools (for compiled language application programs
and Java programs)
Other debugging mechanisms, for example the CICS Execution Diagnostic Facility (CEDF), do
not use debugging profiles. For more information about debugging
profiles, see Debugging profiles.
- NOFORCE
- Do not force user application programs
to run under the QR TCB. CICS honors
the CONCURRENCY(THREADSAFE) attribute on user application programs,
and allows user programs to run on an open TCB to avoid unnecessary
TCB switching.
- NOSYSDUMP
- Specifies
that system dumps are suppressed.
- PROGAUTOEXIT (value)
- Specifies
the name of the user-provided program that the program autoinstall
code calls to select or modify a model definition.
- RUNAWAY (value)
- Specifies
the interval, in milliseconds, for which a task can have control before
it is assumed to be looping.
You can specify 0, or a value in
the range 500–2700000. The value chosen is rounded down to a
multiple of 500. CICS purges
a task if it has not given up control after this interval (that is,
if the task appears to be looping). If you specify zero, runaway task
control is inoperative (that is, tasks do not get purged if they appear
to be looping). The value is independent of, and can be less than,
the TIME value.
CICS runaway-task detection is based upon task
time, that is, the interval is decremented only when the task has
control of the processor. You do not, therefore, need to allow for
the effect of other jobs when setting the value.
- SCANDELAY (value)
- Specifies
the terminal scan delay value for the CICS region,
which is initially set by the ICVTSD system initialization parameter.
The default value is zero. The terminal scan delay facility was used
in earlier releases to limit how quickly CICS dealt with some types of terminal output
requests made by applications, in order to spread the overhead for
dealing with the requests. Specifying a nonzero value was sometimes
appropriate where the CICS system
used non-SNA networks. However, with SNA and IPIC networks, setting
ICVTSD to 0 is appropriate to provide a better response time and best
virtual storage usage. If required, you can reset this value by overtyping
it with a different value in the range 0–5000 milliseconds.
- SYSDUMP
- Specifies
that system dumps are not suppressed.
- TIME (value)
- Specifies
the interval, in milliseconds, for which CICS releases control to the operating system
if no transactions are ready to resume processing. This interval is
known as the region exit interval.
The value can
be in the range 100 - 3600000, and must be greater than or equal to
the SCANDELAY value.
In the summary report
of the dispatcher statistics, the TIME value
is referred to as the ICV time value.