Transaction trace (TTrace) is attached as a daughter task in the system trace address space, after master scheduler initialization completes. Once initialization has completed, and the first transaction trace command is entered with a filter that specifies the attributes of the work unit(s) to be traced, transaction trace is activated. Additional information, such as the use of an external writer, is also allowable for transaction trace processing.
Once transaction trace is activated, WLM Classify invokes a filter exit to determine whether the current work unit is traced. The work unit's attributes are compared with the command filter attributes to determine if tracing should occur. If tracing is required, a non-zero token is built and returned to the Classify caller. If no tracing is performed for that work unit, set the transaction trace token to zero. The caller (CICS® or IMS™, for example) propagates the token in a manner similar to the propagation of the service class token.
Transaction trace writes trace data in a transaction trace data space in the trace address space. When an external writer is defined, the record is also written to the external writer. Use interactive problem control system (IPCS) to view the transaction trace records.