You can use the Undo logs assignment feature to set up multiple
undo logs, which are associated with particular user IDs, job name prefixes,
or high-level qualifiers of VSAM sphere names. When you submit a VSAM sphere
update job that involves undo logging, CICS® VR searches for any matching associations.
When CICS VR
finds an association that applies to a submitted job, it writes undo records
to the undo log named for the association. If no association is found for
the job, records are written to the default undo log that is defined for the
system. Only one undo log can be used for each job.
When you select option 1,
Undo logs assignment,
on the
"CICS VR
settings" panel, option 8 from the
"CICS VR main menu", the
"CICS VR Undo
logs assignment" panel is displayed. This panel lists all the associations
that are currently in effect.
Figure 1. CICS VR Undo logs assignment panelAdministrate View Help
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DWWPPULA CICSVR Undo logs assignment Row 1 to 8 of 8
Select one or more associations, then select an action. Or, use Add action to
register new association.
S Value Type Undo log name Time (GMT)
_ CICSMVS7 HLQ CM7.UNDOLOG 08.181 15:13:12
_ CICSVR2 HLQ TEST.TST2.UNDOLOG 08.181 15:13:17
_ AT* JOBNAME DWW.USER.UNDOLOG 08.185 16:11:08
_ ATEST2* JOBNAME TEST.TST2.UNDOLOG 08.181 15:14:05
_ ATEST1 JOBNAME TEST.TST1.UNDOLOG 08.179 16:01:43
_ AAAA USERID DWW.USER.UNDOLOG 08.185 15:35:24
_ APROD* JOBNAME PROD.UNDOLOG 06.184 13:17:31
_ TESTUSER USERID TEST.TST1.UNDOLOG 06.184 13:17:31
Command ===>
F1=Help F3=Exit F4=SwSort F5=Add F6=Alter F7=Bkwd
F8=Fwd F10=Menu bar F11=Delete F12=Cancel
The list shows the following information about each association:
- Value
- The string that CICS VR tries to match when searching for any association
that applies to a submitted job.
- Type
- The type of association; so whether the value string is a user ID, a job
name prefix, or the high-level qualifier for a VSAM sphere name:
- USERID
- The value for this association is the user ID under which the job runs.
With this association in effect, for every VSAM sphere update job submitted
by this user, undo records are written to the named undo log. The value is
the exact user ID.
- JOBNAME
- The value for this association is the job name prefix of the VSAM sphere
update job. With this association in effect, for every VSAM sphere update
job with a prefix that matches the stated value, undo records are written
to the named undo log. The value can be an exact job name prefix or it can
be a mask ending with an asterisk (*) as a wildcard. For example, the association
shown in the sample listing with a value of ATEST1 matches
only with the job name prefix ATEST1, but the association with a value of ATEST2* matches
with any of the job name prefixes ATEST2, ATEST2MON, or ATEST23.
- HLQ
- The value for this association is the high-level qualifier (HLQ) of a
VSAM sphere name. With this association in effect, for every VSAM sphere update
job that updates a VSAM sphere with the specified high-level qualifier, undo
records are written to the named undo log. The value is the exact high-level
qualifier.
- Undo log name
- The undo log that is used if this association applies to a job. The name
of the undo log consists of a prefix, which can be up to 18 characters, followed
by .UNDOLOG.
- Time
- The time when the association was last updated.
You can sort the list of associations by association value, association
type, or undo log name. To sort the list, press F4, SwSort, to loop through
the different sorting types. Each time you press F4, the list is repopulated
based on the new sorting type.
Matching rules for associations
CICS VR must
find only one matching association to select the correct undo log for a particular
VSAM sphere update job. You do not have to define all the types of association
for each job. For example, if CICS VR finds a user ID association for
a particular job, it can select the correct undo log on this basis, and does
not need to find a job name prefix association and high-level qualifier association
as well.
However,
because you can define different types of association, some VSAM sphere update
jobs that you submit might match the value for more than one association.
For example, a job might be submitted with the job name prefix ATEST2, to
update a VSAM sphere with a name that has the high-level qualifier CICSVR2.
This job matches more than one association in the sample listing. Because
only one undo log can be used for each job, CICS VR applies some matching rules to
make sure that it has selected the undo log that you intended for the job:
- The user ID associations are searched first, followed by the job name
prefix associations, followed by the high-level qualifier associations.
- If a match is found with an association of one type, CICS VR continues
searching all the remaining association types, to check that no conflicting
associations of other types occur. If another matching association is found
that names a different undo log, CICS VR undo logging produces an error
and does not start. For example, if a job is submitted with the job name prefix
ATEST2 to update a VSAM sphere with a name that has the high-level qualifier
CICSVR2, CICS VR
finds a matching association for both the job name prefix and the high-level
qualifier. Because these associations both name the undo log TEST.TST2.UNDOLOG,
they do not conflict, and the undo logging can proceed. However, if the same
job is submitted with the job name prefix ATEST1, a matching job name prefix
association exists that names the undo log TEST.TST1.UNDOLOG, followed by
a matching high-level qualifier association that names the undo log TEST.TST2.UNDOLOG.
In this case, you have a conflict, and the undo logging cannot proceed.
- For job name prefix associations, if you have set up associations using
masks, and a job name prefix therefore matches the value of more than one
association, CICS VR
selects the association with the fullest match. For example, the sample listing
includes job name prefix associations with values of AT*, ATEST2*, and ATEST1.
For a job submitted with the job name prefix ATEST23, CICS VR selects the association with a
value of ATEST2*, rather than AT*,
because that is the fullest match.
- If you are updating multiple VSAM spheres in the same job, and you have
no matching user ID association or job name prefix association, all the VSAM
sphere names must have a high-level qualifier association, and these must
all point to the same undo log.
- If you have no high-level qualifier associations in effect at all for
the VSAM spheres in the job, that is also acceptable. If CICS VR finds
that one of the VSAM sphere names has a high-level qualifier association pointing
to a different undo log, or that some have matching associations but others
do not match any association, CICS VR undo logging produces an error
and stops. This error cannot be discovered until processing starts against
the first VSAM data set that is different from those encountered previously.
- If a matching user ID association or job name prefix association for the
job exists, it is not important if some of the VSAM sphere names do not match
any association, but it is important if they have associations pointing to
different undo logs, because of a conflict.
If
an error occurs, the job proceeds without undo logging.
If no matching
associations of any type are found for a job, the undo records are written
to the default undo log that is defined for the system. The prefix for the
default undo log name is specified in the CICSVR_UNDOLOG_PREFIX(prefix) parameter
in the active IGDSMSxx member of SYS1.PARMLIB. The default prefix is DWW,
so the default name for the default undo log is DWW.UNDOLOG.
You must define the default undo log before you submit any job involving undo
logging. CICS VR undo logging explains
how to define an undo log.