Configuring CICS CCTL connections to IMS DBCTL systems

To connect CICS® to databases managed by IMS DB, you must define the CICS resources and initialize the IMS DBCTL system.

• Define CICS resources
  If you use DBCTL exclusively, define the PSBs and DMBs in IMS by using one of the following methods:

  • Use the APPLCTN and DATABASE macros.
  • In systems that have dynamic resource definition (DRD) enabled, use the commands CREATE DB and CREATE PGM.
  • In systems that have dynamic resource definition (DRD) enabled, use the Program Creation user exit routine (PGMCREAT) to define the PSBs that are associated to programs scheduled in BMP and JBP dependent regions.

  If you want to function-ship requests to a remote CICS system, in which the database manager can be DBCTL or remote DL/I (function-shipping), you need to generate a PDIR only.

  CICS routes DL/I requests to remote DL/I or DBCTL according to the PSB that is named. If the PSB does not appear in the CICS PDIR, and CICS is connected to DBCTL, CICS routes the request to DBCTL.

  Related reading: Refer to CICS Transaction Server for z/OS® CICS System Definition Guide and CICS Transaction Server for z/OS CICS Resource Definition Guide for information on defining PDIRs and DDIRs.

• Initialize IMS DBCTL
  Use the procedure library member DBC to initialize the DBCTL subsystem. Also generated are procedures for DBRC and DL/I, which are used to initialize the DBRC and DL/I address spaces. The DBRC and DL/I procedures are started automatically by DBCTL during DBCTL address space initialization. All three procedures use positional parameters on the EXEC statement:

  PARM='region type, parm1, parm2, parm3,...'

  The region types specified are:

  PARM='DBC' for DBCTL
  PARM='DRC' for DBRC
  PARM='DLS' for DLISAS

  When all three address spaces have been initialized successfully, DBCTL issues:

  DFS989I DBCTL READY

  When the READY message is received, the IMS console operator enters a /START command. The commands options are:

  • /NRESTART CHECKPOINT 0 for a cold start with no previous shutdown
  • /NRESTART for a warm start
  • /ERESTART for an emergency restart after a failure

  Related reading: See CICS Transaction Server for z/OS IMS Database Control Guide for additional details.