SNAX/HLS Diagnosis and Support Manual

Trace Analysis Interpretation
Using SNAX/HLS Trace Analysis Program
104706 Tandem Computers Incorporated 2–31
Trace Analysis
Interpretation
The HLSTAP utility formats traces configured by using HLSCOM commands. These
HLSCOM commands allow the specification of which trace data to accumulate on a
session. The trace selections for one session are independent of the selections for
another session. All sessions established can be traced automatically from their
inception if you use the INITIAL^TRACE configuration parameter. (For more
information, see the SNAX/HLS Configuration and Control Manual.)
The information that can be accumulated on a session is:
Verb input and output. At this level, a trace of all verb requests into SNAX/HLS
and all verb replies out of SNAX/HLS pertaining to the session can be requested.
This trace is used to determine application program problems.
LU service calls. At this level, a trace of internal scheduling events that
SNAX/HLS executes on behalf of the session can be requested. This is, in essence,
a dispatcher trace and is intended for SNAX/HLS internal problem determination.
Data flow control (DFC). At this level, a trace of before and after DFC finite state
machines of the session can be requested during the course of message processing.
This trace is intended for SNAX/HLS internal problem determination.
SNALU I/O. At this level, a trace of session messages to and from the SNALU
interface can be requested. (Recall that SNAX/HLS uses the SNALU interface to
communicate with a Tandem SNA access method such as SNAX/XF.)
You are encouraged to read the introductory statements in the IBM SNA Format and
Protocol Reference Manual for more information on the SNA constructs used in
SNAX/HLS.
To help you understand where trace records are produced by SNAX/HLS, Figure 2-3
shows a simplified diagram of trace record generation.