The global trap exit DFHTRAP

The global trap exit DFHTRAP is an Assembler language program that can be invoked when the CICS trace domain is called to write a trace entry. DFHTRAP is intended to be used only under the guidance of IBM® Service personnel, to make a detailed diagnosis of a problem without having to stop and restart CICS®.

Typically, the global trap exit is used to detect errors that cannot be diagnosed by other methods:

Errors that occurred some time before the effects are noticed
Errors that cause intermittent problems that are difficult to reproduce

For example, a field might be changed to a bad value, or some structure in storage might be overlaid at a specific offset.

A skeleton version of DFHTRAP is supplied in both source and load-module forms. The source of DFHTRAP is cataloged in the CICS690.SDFHMAC library.