The daily batch cycle is becoming more complex every day with additional
ftps and charge jobs. This additional complexity makes scheduling to prevent
file contention nearly impossible. MVS's Dynamic allocation can be used to
dramatically increase to probability that a data set or set of data sets will
be available for use when required.
A program is available that will determine the availability of a data set
or group of data sets, wait for their availability and pass a return code to
indicate their (un)availability. The program name is DR0475BA and it resides
in the 'NPAPPL.BATCH.LOADLIB' link list data set.
DR0475BA has several keyword parameters to control is behavior. A keyword
parameter is a parameter of the form 'keyword=value'. The table below specifies
the keywords, their use and their default values. All of the keywords are
optional, but if no keywords are specified, the name of the data set(s) to
insure availability of must be input via 'SYSIN DD'.
Keyword Value Meaning Default
------- ----- ---------------------------------------------------- -------
DISP= * Disposition of allocated data set(s) SHR
FREE= Y(es) Free immediately upon successful allocation Yes
N(o) Hold data set until end of step
CONT= Y(es) Continue even if allocation fails No
N(o) Terminate step on 1st failure
TIME= # Number of seconds to loop waiting for data set 60
LOOP= # Number of loops to attempt to allocate data set 10
DSN= dsn The data set name to attempt to allocate none
* as defind in IBM standard JCL (SHR,OLD,MOD,NEW)
# numeric value 1 thru 65535 (unsigned binary halfword)
Examples: PARM='DISP=OLD,DSN=VPPMV.PROD.YISEGMD,TIME=5,LOOP=20'
PARM='DISP=SHR,FREE=YES,CONT=YES'
PARM='DSN=NPPM3.PROD.D.PMCNTROL'
If all specified data sets are successfully allocated with the required disp,
the return code will be zero. If any data set can not be allocated, the rc
will be 4.
To be effective, the data sets allocated by DR0475BA must be allocated as soon
as possible by the next job step. If the data sets are in separate steps, use
individual executions of DR0475BA to insure availability before each step.
If multiple data sets are required, they must be input via SYSIN DD with the
data set name beginning in column 1.
Examples: //STEP01 EXEC PGM=DR0475BA,PARM='DISP=OLD'
//SYSOUT DD SYSOUT=*
//SYSIN DD *
VPPMV.PROD.YICPIMD
VPPMV.PROD.YAAPMMD
VPPMV.PROD.YISEGMD
/*
A sample production job using DR0475BA is PCCC$3C2.