Note on terminology: DBCTL refers to the CICS®—IMS/ESA® DBCTL (database
control) interface.
The recoverable service table (RST) is used for CICS DBCTL XRF (extended recovery facility) support. It contains a description
of the DBCTL configuration. On detection of a DBCTL failure, the active CICS
system uses the RST together with the MVS™ subsystem VERIFY to determine the existence
of a suitable alternative DBCTL subsystem. The alternate CICS system
uses the RST to check for the presence of a DBCTL subsystem. For security
reasons, the RST should be link-edited into a library authorized using APF. The RST is not loaded as part of the CICS nucleus.
You can code the following macros in a
recoverable service table:
- DFHRST TYPE=INITIAL establishes the control section.
- DFHRST TYPE=RSE specifies the start of a recoverable service element (RSE).
An RSE consists of a (nonempty) set of identifiers of equivalent DBCTL subsystems,
the CICS applids associated with these DBCTL subsystems, and the application
identifiers of the CICS systems which use the DBCTL subsystems.
- DFHRST TYPE=SUBSYS specifies one of the DBCTL subsystems in an RSE.
- DFHRST TYPE=FINAL concludes the RST (see TYPE=FINAL (end of table)).
The RST to be used by the system must be defined in the system
initialization table by the following system initialization parameter:

.-NO-.
>>-DFHSIT--...--,RST=--+----+----------------------------------><
'-xx-'