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Appendix C. Analyzing CICS restart information
You can programmatically determine the type of CICS shutdown that occurred and
whether it is safe to override the next restart type and perform a cold restart of the
CICS system.
DFHRMUTL provides the SET_AUTO_START keywords to allow a CICS system to
be auto-restarted with a given override. This can include AUTOCOLD, to make
CICS perform a cold start. Care should be taken when performing such a change. A
CICS system that was shutdown warm, and which had no indoubt, commit-failed, or
backout-failed units of work (UOWs) keypointed at that time, can be restarted cold
without loss of data integrity. However, if the system was not shutdown in a
controlled manner, or there are such units of work recorded on the system log, a
cold restart should not be performed, because system data integrity can be
compromised.
To help you determine whether a cold start of the region system is appropriate or
not, CICS provides the following information:
1. The following DFHRMUTL summary information:
v The next CICS start type found on the global catalog, DFHGCD.
v If the next CICS start type is warm, counts of those units of work that were in
an indoubt, commit-failed, or backout-failed state when CICS was shut down.
2. A CICS global catalog record with the following VSAM KSDS key:
X’00000011C4C6C8D9D4C4D440C4C6C8D9D4C4D46DD9C5E2E3C1D9E340’
This record contains three fullword counts following the key. These are:
a. The number of indoubt UOWs
b. The number of commit-failed UOWs
c. The number of backout-failed UOWs
If any of these counts contains a number greater than zero, recovery
information for these units of work is present on the CICS system log. In this
case, a modification of the CICS autostart override record to AUTOCOLD is not
appropriate, because system data integrity would be jeopardized.
CICS deletes this global catalog record during restart, and writes it during a
controlled shutdown. Therefore presence or absence of the record on the
catalog indicates whether the CICS system was previously shutdown warmly
(that is, by the use of CEMT PERFORM SHUTDOWN) or not. If the record
exists on the global catalog, and the three count fields are zero, it is safe to use
DFHRMUTL to modify the autostart override record to AUTOCOLD.
Here is an example of this record, showing the presence of one indoubt unit of
work at the time CICS was shutdown:
KEY OF RECORD -
00000011C4C6C8D9D4C4D440C4C6C8D9D4C4D46DD9C5E2E3C1D9E340
00000011C4C6C8D9D4C4D440C4C6C8D9D4C4D46DD9C5E2E3C1D9E34000000001
0000000000000000
You can use the DFHRMRED Assembler DSECT in a batch program to map the
global catalog record. DFHRMRED is found in the CICSTS32.CICS.SDFHMAC
library.
For more information about the DFHRMUTL utility, see the CICS Operations and
Utilities Guide.
© Copyright IBM Corp. 1977, 2011 871