This document describes purpose and usage of a Natural Global Buffer Pool (GBP) under the operating system z/VSE.
The following topics are covered:
Certain parts of the Natural global buffer pool are identical under z/VSE and z/OS. These parts are concentrated in a separate section (see Common GBP Operating Functions under z/OS and z/VSE) which covers the following topics:
See also:
Natural Global Buffer Pool Manager Messages in the Natural Messages and Codes documentation
The Natural global buffer pool is a segment of storage assigned from the z/VSE system GETVIS storage above 16 MB (or from storage below, if requested), used by Natural to load and execute Natural programs. The Natural global buffer pool is allocated in storage key 9, so that all participating partitions have write-access to it.
Using a global buffer pool, multiple Natural sessions under different TP monitors (multiple copies of CICS, Com-plete, etc.) and/or in multiple batch sessions share the same area - thus requiring less storage than would be required for a local buffer pool in each environment.
A Natural global buffer pool under z/VSE requires the subsystem storage protection facility of an ESA/390 or compatible processor. Consequently, it also requires a minimum operating system level of z/VSE Version 2 Release 4 for support of this hardware feature.
No installation procedure required. The global buffer pool is operated by program NATGBPvr which is contained in and executed from the Natural load library.
The functions available from
NATGBPvr are activated in that they
are
provided by a parameter card (PARM=),
read from a file (see below)
or supplied by the operator (AR command
MSGxx with
xx being the z/VSE partition ID) unless
NATGBPvr has not been terminated.
NATGBPvr expects the first command in the
parameter field (PARM=) of the EXEC job
control statement.
You may enter:
one of the functions described in the section Common GBP Operating Functions under z/OS and z/VSE
or a reference to an input file with
CF=<dlbl-name>, where
<dlbl-name> represents a DLBL
name defined in the JCL or the z/VSE (partition) standard labels. 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. An asterisk
(*) for <dlbl-name> indicates to
NATGBPvr that input has to be read from
SYSIPT. A file is processed until End-Of-File (EOF).
Example: PARM='CF=SYSIN1'
If the parameter field is not supplied or is blank, the commands will
be read from SYSIPT 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 the parameter card, from file input or from
operator console input is shown on the operator console and is logged to
SYSLST.
To start program NATGBPvr
submit a job that executes
NATGBPvr.
Important:
To ensure that the global buffer pool is retained after a
system failure, the global buffer pool should be started automatically during
machine IPL.
After all commands are processed,
NATGBPvr terminates unless
RESIDENT=Y
was specified or
a buffer pool with a cache was created.
NATGBPvr will return one of the
following condition codes:
| 0 | All functions executed successfully. |
| 20 | An error has occurred; see the message log for details. |
The following examples show sample batch jobs for creating and terminating a global buffer pool.
In the following examples, the notation vrs or vr stands for the relevant version, release, system maintenance level numbers. For further information on product versions, see Version in the Glossary.
// JOB GBPSTART /* /* Starts a global buffer pool with the name NATvrGBP, a size of 1 MB and /* a text block size of 4 KB. The global buffer pool is allocated above 16 MB. /* The subsystem used is NATv. /* After the allocation, the job GBPSTART terminates. /* // LIBDEF PHASE,SEARCH=SAGLIB.NATLIB // EXEC NATGBPvr,SIZE=NATGBPvr,PARM='BPN=NATvrGBP,N=(1000)' /* // EXEC LISTLOG /&
// JOB GBPRES /* /* Starts a global buffer pool with the name GBP, a default size of /* 100 KB and a text block size of 1 KB. The global buffer pool is allocated /* below 16 MB. The subsystem used is SAGS. /* After the allocation, the job GBPRES will wait for further commands. /* Further commands may be entered using AR command MSG partition-id: /* the job GBPRES will then prompt for console input. /* // LIBDEF PHASE,SEARCH=SAGLIB.NATLIB // EXEC NATGBPvr,SIZE=NATGBPvr,PARM='BPN=GBP,N=(,BL,1),S=SAGS,R=Y' /* // EXEC LISTLOG /&
// JOB GBPSTOP /* /* Stops the global buffer pool GPB if it contains no active objects. If it /* does contain active objects, the operator console will prompt for a reply. /* Depending on the reply, the shutdown will be forced (Y) or aborted (N). /* The subsystem used is NATv. /* // LIBDEF PHASE,SEARCH=SAGLIB.NATLIB // EXEC NATGBPvr,SIZE=NATGBPvr,PARM='FSHUT,BPN=GBP' /* // EXEC LISTLOG /&
// JOB GBPSTRT2 /* Read commands from SYSIPT: /* /* Start 3 global buffer pools (subsystem id Nvrs) with name /* NATGBP1 - size=1024KB and a cache with size 2048KB /* NATGBP2 - size=2048KB without cache /* Display all buffer pools of subsystem id "Nvrs". /* /* Note: The job does not terminate by itself, but stays resident and waits /* for operator commands, because it owns the data space allocated for /* buffer pool NATGBP1. /* /* If the buffer pools should shut down, wake up sleeping job by MSG partition-id /* and enter parameter "CF=*" to execute the corresponding FSHUTs. /* // LIBDEF PHASE,SEARCH=SAGLIB.NATLIB // EXEC NATGBPvr,SIZE=NATGBPvr CREATE,BPN=NATGBP1,S=Nvrs,N=(1M),BPC=2M CREATE,BPN=NATGBP2,S=Nvrs,N=(2M) SHOWBP S=Nvrs /* FSHUT,BPN=NATGBP1,S=Nvrs FSHUT,BPN=NATGBP2,S=Nvrs SHOWBP S=Nvrs /*
The module NATGBPTX is delivered in source form. It
contains all error messages in English in mixed case. The messages can be
translated into other languages as required. In this case, the
"new" NATGBPTX source module has to be assembled and
NATGBPvr has to be relinked.
To issue the global buffer pool messages including their variable parts
in upper case, the global buffer pool parameter module NATGBPRM
has to be assembled with the UCTRAN parameter set to
YES, and NATGBPvr has to
be relinked.
To relink NATGBPvr, use the
following JCL:
// OPTION CATAL,LIST ACTION NOAUTO,SMAP PHASE NATGBPvr,* INCLUDE NATGBPMG INCLUDE NATGBPRM INCLUDE NATGBPTX INCLUDE NATBPMGR ENTRY CMSTART /*
