Dump analysis introduction

In a pseudoabend supervisor call (SVC) dump that is generated by module DFSERA20, you can find the failing program specification table (PST) by searching the save areas for the caller of module DFSERA20. In the save area flow, DFSERA20 is called INTERA20 and register 1 contains the failing PST address.

The SNAP call facility identifies calling routines that generate snap dumps. SVC dumps are generated only for the intended abend codes or status codes, and for unknown calling routines.

The following list provides general considerations for dump analysis:

The first request block (RB) on the RB chain represents the IMS batch region controller (DFSRRC00). The second RB on the RB chain represents the batch program controller (DFSPCC30). Module DFSPCC30 always links to the application program that is named in the parameter field of the EXEC statement. Therefore, the application program must be represented by the third RB. However, if the application program uses an IMS service, and that service abends, the third RB points to the offending IMS routine.
The last two SVRBs represent ABEND and ABDUMP. The register contents at the time of abend are usually found in the first abend SVRB. The IMS STAE work area (DFSFSWA0) and the RTM work area in z/OS® are also used to hold the register contents at abend time.
There are two PSTs in a batch environment. One is used for all application calls and the second is used for background write whenever it is activated.
Each PST has a 20-level save area set as part of the PST. When the abend occurs, ABDUMP prints the save areas that are associated with the active PST.
At abend time, the IMS STAE routine gets control to flush the database buffers and close the log data set. It builds six additional save areas and chains them to the last save area in the active PST. The IMS STAE routine is partially contained within module DFSPCC30 and has an entry ID starting with the characters PCE.
Most IMS modules use register 12 as a base register.