This document explains the features of Natural Advanced Facilities specific to a CICS environment.
NATSPOOL accumulates all reports generated during a Natural user session
in the spool file. To physically print a report, NATSPOOL schedules a
Natural session at the physical printer by issuing an EXEC CICS START
command.
This new Natural session, the NATSPOOL spool server, retrieves various
dynamic parameters from the task which has issued the START request.
The logical connection between the two Natural sessions used by NATSPOOL
is shown below.
To install NAF in a CICS environment, set the NATSPOOL parameters listed
below.
You can also specify these parameters with Function 30.5 (Set Spool Option) as described in Layout of Spool File. After Natural Advanced Facilities has been installed, use Function 30.5 to set the CICS options.
| Parameter | Explanation |
|---|---|
INITEXI=OFF/ON |
Specifies whether the NAF initialization exit is executed. This exit requires exclusive control (ADABAS EXU USER) by the spool file. |
INITMCO=OFF/ON |
Specifies whether the initialization exit sends messages to the console. |
INITMLO=OFF/ON |
Specifies whether the initialization exit sends messages to the CICS log file. |
INITSID= name |
Specifies the CICS SYSID that performs the initialization exit. |
PRINSID= name |
Specifies the default CICS SYSID for the spool server used if
no SYSID has been specified for the printer on the spool file (see
also Function
31.4 in the section Objects - Function
31).
|
TRANP= name |
Specifies the CICS transaction ID of the spool server. The name specified
must be identical to the corresponding name specified as transaction ID in the
CICS PCT. This PCT entry must point to the Natural load module, that is,
NATP starts Natural.
For performance reasons, we highly recommend that you select different names for the spool server transaction ID and the terminal transaction ID. |
TRMTASK=OFF/ON |
Specifies that the spool server terminates and another task starts each
time a single report has been printed.
Specifying |
You can omit a parameter or set the value (OFF/ON or
name) assigned to blank.
The following rule of precedence applies to the use of parameters:
For all parameters that have not been defined in NAFPRMC or have been
set to blank, the corresponding values defined in the spool file applies.
Parameters that have been defined in the NAFPRMC parameter module by
setting the value not equal to blank rank before the values defined on the spool
file. As a result, you can use the NAFPRMC parameter module to set
certain options for certain tasks only. This can be useful for several CICS
environments sharing the same spool file.
CICS contains a facility called Intercommunication Support, which allows different CICS regions to share resources and communicate with each other. Multiple Region Operation (MRO) is a CICS facility which provides such support for regions within the same processor.
The MRO function-shipping option allows programs in the "application-owning" (local) region to access resources in the "resource-owning" (remote) region, by shipping appropriate requests to the remote region.
These requests are carried out in the remote region by a mirror transaction provided by CICS. The resources accessed can also be transactions, in which case the process is known as Remote Transaction Initiation.
Using the MRO approach, it is possible to ship the START request of the
asynchronous NATSPOOL spool server to a remote region (that is, to print in
such a region).
The MRO option is useful if growth of tasks is anticipated, because there are constraints on the number of tasks a CICS region can manage.
When a spool server is started, three different types of dynamic parameters apply:
- Parameters set up by the spool server itself
To allow for dedicated Natural Advanced Facilities threads of minimum size, the spool server always allocates buffers of minimum size. Most sizes are set to 0.
- Parameters passed from the user session to the spool server
The spool server and the user session which started the spool server always use the same system files (
FNAT,FUSER,FDICandFSPOOL), the same buffer pool (BPID), and the same setting of theRCAparameter.- Parameters defined in the Natural parameter module
All further parameters not mentioned above are taken from the Natural parameter module.
The definition of the system file(s) in the Natural parameter module can be overwritten
by the user. This is accomplished by specifying any of the corresponding file parameters
(DBID, FNR, FDIC,
FNAT, FSEC or
FSPOOL) dynamically when starting a Natural session. The actual
values will then be transferred by the originating terminal task to the spool server.
This holds both for spool servers started automatically and for spool servers started by
using NATSPOOL functions.
When DBID or FNR are processed, the
supplied value is also applied to the spool file specification.
Once the spool server has been started, it will observe these file definitions for as
long as the task is active. Reports will be printed only from the file defined by the
currently active FSPOOL, even if there are reports with the same
Destination/Form on another FSPOOL file.
In this way a unique CICS spool server is able to manage reports created on different spool files under the same CICS (for example, for production or test processing).
Before starting a spool server, NATSPOOL checks if the terminal status of
the printer allows internally generated session requests to create a session
(TRMSTAT=INTLOG or CREATESESS=YES). If this is not the case,
for example after VTAM LOSTERM errors, NATSPOOL forces this
status and then tries to start the spool server.
After startup of CICS, when the first Natural session is invoked, the spool file is
scanned for printers or reports interrupted during the previous CICS session.
Interrupted printers which are not in status DEAC are reset to status
FREE, interrupted reports to status TOBE. 20 seconds after
this first stage of initialization, all interrupted printers are restarted with the
interrupted Destination/Form. The interval of 20 seconds allows this first stage of
initialization to finish as an exclusive user of the spool file.
The Natural initialization ensures that the spool file is to be updated under exclusive control of this first session. Other starting sessions will be delayed until this part of the initialization has finished.
If an error is encountered during scanning the spool file, the system operator is notified, the scan is terminated normally, and Natural initialization continues.
This scan is performed for the defined spool file, that is, dynamic setting of
FSPOOL is also taken into account.
If the spool file is shared among CICS sessions, the spool file scan must be disabled
(see Function
30.5 and the NAFPARMC parameter module in
Installing Natural Advanced
Facilities under CICS on z/OS) because it requires exclusive
control of the spool file.
If a spool server terminates normally, each printer is checked for status
INOP. If a printer is found to be in status INOP and no
alternate printer is available, the printer is set to status PEND, and the
spool server tries to start again on that printer. If the printer becomes
INOP again, the same procedure is repeated twice. Afterwards, a restart
is no longer attempted on that printer.
Support for SNA character string (SCS) printers is provided.
The data stream to SCS printers may only contain user data and SCS control codes. It must not contain a write control character (start printer bit) or orders (such as the end-of-message character). The SCS control codes perform functions similar to orders, in that they allow the output to be formatted, however, the range of control is greater.
The only SCS control codes used by NATSPOOL are FF (form
feed) and NL (new line).
It is only possible to have one spool transaction ID per Natural transaction ID.
The operation mode of the spool server can be defined with Function 30.5 or the
NAFPARMC parameter module as described in Installing Natural Advanced Facilities
under CICS on z/OS.
By default, the NATSPOOL spool server operates as a pseudo-conversational
CICS task (that is, in Terminate Task=Y mode). The spool server will then
be terminated (and another task will be started) each time a single report has been
printed. Pseudo-conversational mode of operation is recommended if there are several
physical printers active at the same time.
Specify Terminate Task=N to run in conversational mode. The same CICS task
prints all reports with the same Destination/Form. Conversational mode is recommended if
not many physical printers are active at any one time, and fast printing is required.
Otherwise, the maximum number of active CICS tasks (AMXT keyword in CICS
SIT) may be reached.
Before sending output to a printer, the spool server rolls out the session to release the thread. This allows the thread to be released if the printer is interrupted while printing, for example, when running out of paper or switched off. After the output has been sent successfully, the session is rolled in again. Since relocation is turned off during this roll request, the same thread is selected.
