CA IDMS VSAM Transparency Architecture › Request Processing Modules › The CA IDMS VSAM Transparency Front End

The CA IDMS VSAM Transparency Front End

The CA IDMS VSAM Transparency front end is the application request processing module that does the following:

• Initializes and terminates files through the open/close processing routine. This routine:
  • Opens and closes files
  • Initializes and terminates the front-end control blocks at the job level (for batch processing), transaction level (for CICS processing), and file level (for either batch or CICS processing)
  • Calls the back-end module for back-end control block initialization or termination
• Interfaces with batch applications through the batch interface routine. This routine:
  • Receives batch process calls (GET, PUT, POINT, ERASE, ENDREQ, CHECK)
  • Saves the user environment
  • Sets up the CA IDMS VSAM Transparency environment
  • Calls the communication manager routine

  For CICS, the batch interface is functionally replaced by the CA IDMS VSAM Transparency CICS interface.

• Handles all communication between the VSAM application and the back end through the communication manager routine. This routine:
  • Validates application requests
  • Transmits processing requests to the back-end module
  • Receives data and status information from the back end and transmits this information back to the VSAM application