IMS QC status code returned on CHKP call

Problem

When running a BMP, the program was getting a QC status code when issuing a CHKP call.

Resolution

The customer had taken the JCL from the Mainframe where they were running the job (DFSRRC00) as a batch DLI program but the parms are different between DLI batch and BMP.

Solution was to remove the 4th parm (which in DLI batch is the number of buffers) because in the BMP version of DFSRRC00 the 4th parm is the IN parm which specifies an input transaction code. This parameter is necessary only when the application program intends to access the message queues.

If the program type is a BMP and the JCL specifies an INPUT transaction it is assumed to be a message queue driven BMP.   Message driven BMPs expect to receive an input message returned on CHECKPOINT calls and if there are no more input messages then a QC status code is returned.