Non-stop TRAN and PSB after an application abends

In IMS 15, the DFSNDMX0 exit can be programmed to control transactions and programs when IMS calls the exit after an application abends in an IFP region. This enhancement is delivered through APAR PH 31457.

A system administrator can code the Non-Discardable Messages exit (DFSNDMX0) exit to specify what happens to transactions and programs when IMS calls the exit after an application program abends in an IFP region. This enhancement provides the system programmer a more consistent mechanism to control the transactions and the programs after an application abends, across all dependent region types.

The DFSNDMX0 exit has been enhanced to support the message driven IFP regions operation. A system programmer can now program the exit to specify the following transactions status:

  • 1 DO NOT (U)STOP TRAN OR PSB
  • The following Return Codes of the DFSNDMX0 exit will be supported for IFP region.
    • 0 = CONTINUE NORMAL PROCESSING
    • 4 = DISCARD THE INPUT MESSAGE FROM THE MESSAGE QUEUE

Due to the Fastpath architecture and way of operation, all return codes of the of the DFSNDMX0 exit are not supported for IFP regions operation. Return code 0 and 4 will be supported while return code 8, 12, and 16 will not be supported. Return codes other than 0 and 4 will be treated as 0. For more information about the DFSNDMX0 exit routine, see NDMX: Non-Discardable Messages user exit (DFSNDMX0 and other NDMX exits).

Migration considerations

To enable calling the NDMX exit for IFP regions, code the new optional parameter and keyword, NDMX_CALLED_FOR=(IFP(Y)), on the USER_EXITS section of the DFSDFxxx member. The EXITDEF and NDMX_CALLED_FOR must be specified to enable the IFP region support.

Log record changes

The following log records are new or changed by this enhancement in IMS 15:
Table 1.
Log record Description of enhancement
X '67D0'

DFS67D0

A new one byte field, D0CRGTYP, has been added to the subtype x'0C' log record written by DFSNDMI0 during NDM user exit interface processing to indicate the type of IMS dependent region processed. The D0CRGTYP field will contain one of the following values:

  • x'88' = Java Message Processing Region (JMP)
  • x'80' = Message Processing Region (MPP)
  • x'50' = Message Driven Fast Path Region (IFP)
  • x'40' = Message Driven Batch Message Processing Region (BMP)

Changes to exit routines

The DFSNDMX0 exit routine has been enhanced to support the message driven IFP regions operations. To activate the support for message driven IFP regions, specify additional parameter NDMX_CALLED_FOR(IFP(Y)) in the USER_EXITS section of the DFSDF member. An example can be found in the USER_EXITS section of the DFSDFxxx member in the IMS Systems Definition Manual.

Documentation changes

The following table lists the publications that contain new or changed topics for the New function name enhancement. Publications that are not impacted by this enhancement are not included in the table.

Table 2. Links to topics that have new or changed content for this enhancement
Publication New or changed topics
Release planning
System definition
Exit routines