Trace entries produced by DBCTL

In DBCTL, tracing is started by specifying an option in member DFSVSMxx in the IMS.PROCLIB (where xx is the suffix specified by VSPEC= in the DBCTL startup JCL).

See System definition in IMS product documentation for guidance on the DFSVSMxx member. Alternatively, you can start tracing dynamically with the /TRACE command. (See Operations and automation in IMS product documentation for guidance on the /TRACE command and its keywords.)

In DBCTL, you can start PI tracing in the DFSVSMxx member of the IMS.PROCLIB, as explained here. Alternatively, you can start PI tracing in DBCTL by issuing the command: 
/TRACE SET ON PI

DBCTL produces an external trace when DL/I requests are issued to be processed by DBCTL. This trace corresponds to the CICS® trace for a DL/I request being processed by DBCTL, as shown in Figure 1. (DBCTL does not produce any external traces that correspond with the other CICS trace examples given.)

Figure 1 shows an example of the trace records produced when you use the DL/I trace table. To start the DL/I trace table, DLI=ON must have been specified in the DFSVSMxx member of IMS.PROCLIB. Specifying DLI=ON also enables program isolation and lock trace. For guidance on specifying DLI=ON, see System definition in IMS product documentation. Alternatively, you can start DL/I tracing dynamically using the /TRACE command, as follows: 
/TRACE SET ON TABLE DL/I
For a more detailed example, see Operations and automation in IMS product documentation, example 8.
Figure 1. X'AC' trace entry
The example X'AC' trace entry contains 64 alphanumeric characters, in eight groups of eight. They are briefly identified in the figure, and further explained in the paragraph which follows it. In the first group of eight characters, AC070E87, the first two characters, AC, are the X'AC' database call analyzer entry. The second two characters, 07, are the PST number. The last four characters, 0E87, are the trace sequence number. The second group of eight characters, D9E3D2D5, is an eyecatcher RTKN (recovery token). The third and fourth groups of eight characters are all zeroes, and they are not used. The fifth, sixth, seventh and eighth groups of eight characters are the recovery token. In this example, they are C3C9C3E2, E6D2D8F1, A031BB3E, D5863000.
The DBCTL trace entry shown in Figure 1 includes:
  • X'AC': the database call analyzer entry, which is only present for DBCTL.
  • The partition specification table (PST) number. The PST number is equivalent to a particular DL/I thread number, as displayed using the /DISPLAY command, and can be used to find all DBCTL trace records for a particular thread. (For an example of a thread number being displayed, see Purging a transaction that is using DBCTL.)
  • The trace sequence number.
  • An eyecatcher recovery token. This is the actual characters RTKN, used to draw attention to the recovery token in the same line, and is the same in every X'AC' entry.
  • The recovery token that is passed from CICS via DFHDBAT.

You can print and format this data using the IMS file select and formatting print utility, DFSERA10. You would typically print and format several log types, plus the X'AC' records to enable you to correlate the DBCTL activity with your CICS trace for a DL/I request.