IBM SC34-6814-04 - Manual (Page 286)

v A predatory takeover. A “predatory takeover” can occur, if you are using VTAM
Release 3.4.0 or above, and a VTAM application with the same APPLID as that
of the executing CICS system assumes control of all the sessions of the
executing CICS system.
XXRSTAT gives you the choice of allowing the system which has suffered the
takeover to continue or to terminate.
To avoid potential integrity exposures, CICS default action after a predatory
takeover is to terminate without a dump. If you want CICS to terminate with a
dump, your exit program should return UERCABDU. CICS terminates with the
abend code specified by your exit program.
If you want CICS to continue after a predatory takeover, your exit program must
return UERCCOIG. Message DFHZC0101 is issued and CICS continues
processing without VTAM support. The predatory application assumes control of
all VTAM sessions.
Note: Allowing CICS to continue after a predatory takeover could cause integrity
problems and is not recommended. You are also recommended to use
RACF to protect your CICS APPLIDs.
For more information about this exit and the circumstances in which you can use it,
refer to the CICS/ESA 3.3 XRF Guide.
Exit XXRSTAT
When invoked
After either of the following:
v CICS is notified of a VTAM failure by the TPEND exit.
v A predatory takeover.
Exit-specific parameters
UEPERRA
Address of parameter list containing:
UEPGAPLD
Address of the 8-byte generic applid
UEPSAPLD
Address of the 8-byte specific applid
UEPDOMID
Address of the 4-byte domain ID
UEPERRID
Address of the 4-byte error ID.
Note:
1. No DSECT is provided for the above parameter list. You need to
code your own DSECT to access the named fields.
2. When VTAM has failed, the domain ID is ‘ZC ’ (uppercase Z,
uppercase C, and two blanks), and the error ID is the character
string ‘3443’.
Return codes
UERCNORM
Take the system action. The system action depends on the reason
why the exit was invoked:
264 Customization Guide