This part describes the use of the message buffer pool.
Anmerkung:
The message buffer pool is available under z/OS.
The following topics are covered:
The message buffer pool is a cache memory which is used to store the Natural system messages and the user texts.
Before an error message is output, Natural first checks whether the corresponding message text is available in the message buffer pool. If so, this text is output. Otherwise, the error message would be read from the database, and would be stored in the message buffer pool.
The message buffer pool is available only as a global buffer pool. Its
use is optional, and is controlled by the Natural profile parameter
BPI or the
corresponding macro NTBPI.
When used, the message buffer pool is allocated in a data space.
The following prerequisites must be met if you want to use the message buffer pool:
The module NATMBPvr must have
been linked into an Authorized Program Facility (APF) library; see the
corresponding
step
in Installing Natural on
z/OS in the Installation for z/OS
documentation.
The message buffer pool must have been created and started; see the corresponding step in Installing Natural on z/OS in the Installation for z/OS documentation.
The keyword subparameter TYPE of
profile parameter BPI or macro
NTBPI
must be set to MSG.
The message buffer pool is operated by the program
NATMBPvr which must be executed from
within an Authorized Program Facility (APF) library.
The following topics are covered below:
Anmerkung:
In the following document,
vrs or
vr represents the relevant version of
the product. For information on product versions, see
Version in the
Glossary.
The functions
available from NATMBPvr (see also
Function
Parameters) are activated in that they are
provided by a parameter card (PARM=),
read from a file (see below),
or supplied by the MODIFY operator command
unless NATMBPvr has not been
terminated.
NATMBPvr expects the first
command in the parameter field (PARM=) of the EXEC
statement.
You may enter:
one of the functions described in the section Common Message Buffer Pool Operating Functions,
or a reference to an input file with
CF=<dd-name>, where
<dd-name> represents a DD name
defined in the JCL.
Only "card image" files are supported; that is,
RECFM=F,LRECL=80, and only the first 72 bytes of the input record
are honored.
Every record included from the input file represents a command.
Blank records or records prefixed with an asterisk (*) are ignored.
A file is processed until End-Of-File (EOF).
Example: PARM='CF=SYSIN1'
If the parameter field is not supplied or blank, the commands will be
read from file SYSIN by default.
It is only possible to enter one function at a time at the console, or one function per line using the command file, otherwise an error message will be returned.
Each command received from parameter card, from file input or from operator console input is displayed on the operator console.
To start the program NATMBPvr,
either start a started task or submit a job which executes
NATMBPvr.
The program NATMBPvr is stopped
by using the TERMINATE function (see
Common Message Buffer Pool
Operating Functions) or, in case of emergency, by using
the CANCEL operating program.
The following examples show sample batch jobs for creating and terminating a global buffer pool.
Anmerkung:
In the following examples, v,
vrs or
vr represents the relevant version of
the product. For information on product versions, see
Version in the
Glossary.
//MBPSTART JOB //* //* Starts a message buffer pool with the name NATvrMBP and //* a size of 10 MB. //* The subsystem used is NATv. //* //STEP EXEC PGM=NATMBPvr,PARM='BP=NATvrMBP,SI=10' //SETPLIB DD DISP=SHR,DSN=USER.APF.LINKLIB
//MBPRES JOB //* //* Starts a message buffer pool with the name MBP and a default size of //* 100 MB. The subsystem used is SAGS. //* //STEP EXEC PGM=NATMBPvr,PARM='BP=MBP,S=SAGS'
//MBPSTRT2 //* Read commands from SYSIN1: //* //* Start 2 message buffer pools (subsystem ID Nvrs) with name //* NATMBP1 - size=1000MB //* NATMBP2 - size=2000MB //* If the buffer pools should shut down, send operator command MODIFY with //* parameter "CF=SYSIN2" to execute the corresponding FSHUTs. //* //STEP EXEC PGM=NATMBPvr,PARM='CF=SYSIN1' //SYSIN1 DD * CREATE,BP=NATMBP1,S=Nvrs,SI=1000M CREATE,BP=NATMBP2,S=Nvrs,SI=2000M SHOWBP S=Nvrs //SYSIN2 DD * FSHUT,BP=NATMBP1,S=Nvrs FSHUT,BP=NATMBP2,S=Nvrs //*
The following functions are available:
Anmerkung:
The function names can be abbreviated. It is sufficient to use the
first character only, for example T for
TERMINATE.
This function creates a message buffer pool with the specified parameters.
The message buffer pool with the specified parameters is deallocated.
The message buffer pool operating program is terminated. Prior to that, all active message buffer pools are deallocated.
Displays all Zaps applied to the message buffer pool operating program.
The functions of the message buffer pool operating program can be controlled with the aid of parameters. These parameters can be specified in any sequence. They can be abbreviated.
The following parameters are available:
BPNAME |
Name of message buffer pool. |
BPLIST |
Name of the preload list (optional). |
SUBSID |
Natural subsystem ID. |
SIZE |
Size of the message buffer pool. |
Anmerkung:
The underlined part of the parameter name marks the shortest possible
abbreviation.
BPNAME=value specifies the name
of the message buffer pool to be created.
| Value | Explanation |
|---|---|
| 8 bytes | The name of the message buffer pool.
Anmerkung: |
MTBP |
This is the default value. |
BPLIST=value specifies the name
of the optional preload list.
| Value | Explanation |
|---|---|
| 8 bytes | The name of the preload list.
Anmerkung: There is no default value. |
SUBSID=value specifies the ID
of the Natural subsystem.
| Value | Explanation |
|---|---|
| 4 bytes | The ID of the Natural subsystem.
Anmerkung: |
NATv |
This is the default value, where
v is the first digit of the current
Natural version.
|
SIZE=value specifies the size
of the message buffer pool.
| Value | Explanation |
|---|---|
| 1 - 2000 MB | The size of the message buffer pool. |
100 |
This is the default value. |
Refer to Message Buffer Pool Messages in the Messages and Codes documentation.