Connection program (DFHDBCON)

This program invokes the adapter requesting connection to DBCTL. It can be invoked either from the menu program or from the CICS® PLT.

DFHDBCON issues an ATTACH request of the CICS control program that later carries out resynchronization of indoubt units of work with DBCTL. The control program then issues a WAIT request.

The connection program continues by loading, activating (using the EXEC CICS ENABLE command), and then calling the adapter (using a DFHRMCAL request). A set of parameters is passed to the adapter which includes:
  • The CICS applid
  • The DRA startup parameter table suffix (optional)
  • The DBCTL ID (optional)
  • A set of exit addresses.

As a result of the DFHRMCAL request issued from the connection program, the adapter loads the DRA startup/router module from the CICS STEPLIB library and passes control to it, supplying it with various parameters including the CICS applid, DRA startup parameter table suffix, and DBCTL ID. The DRA startup/router module loads the DRA startup table. It then initiates the processes required to establish the DRA and then returns control to the adapter which, in turn, returns control to the connection program which then terminates. Until this point is reached, any DBCTL requests issued from CICS tasks are rejected by the CICS RMI stub (the DBCTL call processor).

The DRA startup/router module is responsible for establishing the DRA environment, using the parameters specified in the DRA startup table in the CICS STEPLIB library, overridden by any parameters passed to it.

The DRA establishes contact with the DBCTL address space and then invokes the control exit to initiate the resynchronization process.