SNA API Traces May Fail to Capture CMALLC or Allocate Failures

• Microsoft SNA Server, version 4.0

SYMPTOMS

If CPIC or APPC API tracing is enabled for SNA Applications, and the APING sample program is run while the SNA Server service is stopped, the API traces only capture up to the CPIC CMALLC and APPC ALLOCATE requests. Although the APING application fails with a CPIC Error 20, the CPIC CMALLC and APPC MC_ALLOCATE errors and any further API traces are not captured in the trace files.

This problem also affects LU6.2 message tracing. The LU6.2 message traces capture the OPEN(LU62) request, but not the error response.

This problem is not specific to APPC or CPIC applications. This tracing problem can also occur with LUA RUI or SLI applications, if the LUA application ends suddenly after receiving an LUA API error.

CAUSE

The Windows NT SNA Application tracing module (Dbgtrace.dll) fails to flush trace buffer data before the application ends. In this case, the APING program ends immediately after receiving the error, causing the trace buffer to fail to be flushed to the trace file.

STATUS

Microsoft has confirmed this to be a problem in Microsoft SNA Server version 4.0. A supported fix is now available, but has not been fully regression-tested and should be applied only to systems experiencing this specific problem. Unless you are severely impacted by this specific problem, Microsoft recommends that you wait for the next Service Pack that contains this fix. Contact Microsoft Technical Support for more information.

Keywords          : snaappc snacpic snalua snaprog kbbug4.00
Version           : WINDOWS:4.0
Platform          : WINDOWS
Issue type        : kbbug
Solution Type     : kbpending