Contents
Contents for SNA Server Tracing Help

Understanding Tracing

  Overview of Tracing

  Types of Tracing

  Examples of Tracing Used for Specific Difficulties

Starting Tracing

  Enabling or Disabling Trace Options

Trace Options

  SNA Applications: Message Traces

  SNA Applications: Client API Tracing

  SnaServer (PU 2.1 Node) Trace Options

  SnaBase Trace Options

  Link Service Trace Options


trace file

A file containing detailed records of internal activities on the SNA network, including calls made to APIs, the activities of APIs, and the activities of communication links and internal flows.

SNA Server trace files are created in the TRACES subdirectory of the SNA Server root directory, with the filename extension TRC.


tracing

The action of tracking the activities of APIs, communication links, and internal flows, including the calls made to APIs. Tracing stores a history of activity in trace files.

With the Windows NT operating system, SNA tracing can be turned on with the snatrace utility.


event log

A recorded list of SNA Server events, including events involving communications hardware (for example, communications adapters) or SNA Server software. The types of events recorded may include attempts to establish communication, successful establishment of sessions, failures of system components, attempts to use files that are damaged or missing, configuration problems, and responses from remote systems. View event logs with the Windows NT Event Viewer, described in the Windows NT documentation.


Overview of Tracing

When SNA tracing is turned on, the actions carried out by components of SNA Server are recorded in trace files. Tracing provides detailed information about the exact sequence of events occurring within an SNA server, or between an SNA server and another system on the network.

With the Windows NT operating system, tracing is turned on and off with the snatrace utility. Trace files created by snatrace are placed in the TRACES subdirectory of the SNA Server root directory, and have the filename extension TRC.

Note that event logs can provide system information that is more straightforward to interpret than trace files. Trace files, however, provided more detail than event logs.

If you seek product support, the support technician may request trace files, and then guide you through the process of selecting tracing options.

Types of Tracing

Before setting up tracing, decide which software component(s) you want to trace. Trace files can record internal or external activity for the following software components (listed in the Service Name field):

SNA Applications

SNA Server Admin, the graphical interface for SNA Server

SnaBase, the component of SNA Server that maintains lists of service names and statuses

SnaServer (PU 2.1 node), the component of SNA Server that interacts with clients and other nodes on the SNA network

Link services that have been installed with Setup

When you decide which software component to trace, you will also need to decide what type of tracing to apply to that component. The following topics provide information about software components and the types of tracing:

  Types of Tracing

  Examples of Tracing Used for Specific Difficulties

Starting Tracing

After you have decided what software component(s) and what type(s) of tracing to select, you can enable or disable trace options for SNA Server, as described in the following topics:

  Enabling or Disabling Trace Options

  SNA Applications: Message Traces

  SNA Applications: Client API Tracing

  SnaServer (PU 2.1 Node) Trace Options

  SnaBase Trace Options

  Link Service Trace Options

Other Types of Diagnostic Information

The following list shows some other sources of diagnostic information besides tracing:

Windows NT event logs.

The COM.CFG file (configuration file).

Dump files which may be created by SNA Server when a system trap (exception error) occurs.

Datascope or sniffer traces of protocol exchanges.

For more information about the preceding diagnostic tools, see the Microsoft SNA Server Administration Guide or the Help for SNA Server Admin.


Types of Tracing

Before you can select tracing options, you will need to decide which software component(s) to trace, and what type of tracing to apply to the component(s). The two tables in this topic describe the tracing choices available with the snatrace utility.

Type of tracing	Activity traced	Software component(s) that can be traced
Internal*	Activity within a software component of SNA Server	SNA Applications,  SNA Server Admin, SnaBase,  SnaServer (PU 2.1 node),  link services
Message*	Messages passed into and out of a software component of SNA Server, including messages sent to and received from the SNA network	SNA Applications,  SnaBase,  SnaServer (PU 2.1 node),  link services
API	Information passed into and out of an SNA Server DLL, such as the APPC DLL, as the DLL communicates with an application	SNA Applications
*	Internal tracing is intended for the use of product support technicians. Interpreting internal traces and certain types of message traces requires a special knowledge base.

The following table tells the areas of expertise needed for interpreting various types of  traces.

Type of tracing	Software component traced	Area of  expertise needed
APPC API	SNA Applications	APPC programming
CPI-C API	SNA Applications	CPI-C programming
CSV API	SNA Applications	CSV programming
LUA API	SNA Applications	LUA programming
SNA Formats	SnaServer (PU 2.1 Node)	SNA formats
Data Link Control (messages)	SnaServer (PU 2.1 Node) or link service	DLC interface
Level 2 Messages	Link service	Link service interface
3270 Messages	SNA Applications, SnaServer (PU 2.1 Node), or SnaBase	3270 emulator interface
Admin Messages	All software components for SNA Server	Intended for product support personnel
LU 6.2 Messages	SNA Applications, SnaServer (PU 2.1 Node), or SnaBase	Intended for product support personnel
Internal	All software components for SNA Server	Intended for product support personnel


Examples of Tracing Used for Specific Difficulties

The following table gives some examples of tracing used for specific difficulties.

Difficulty	What to trace
SNA Server can't connect to host	For the SnaServer (PU 2.1 node), trace Data Link Control and 3270 Messages
SNA Server Admin doesn't reflect changes in network services	For the SnaServer (PU 2.1 node), trace  Admin Messages; for SNA Server Admin,  enable internal tracing
Windows NT-based client can't connect to an SNA resource	On any client: enable internal tracing On a 3270 or LUA client: For SNA Applications, trace 3270 messages On an APPC or CPI-C client: For SNA Applications, trace LU 6.2 messages


Enabling or Disabling Trace Options

After you have decided what software component(s) to trace and what type(s) of tracing to use, you can enable or disable trace options with the snatrace utility.

To enable or disable trace options

1	If you have not already started the SNA Server tracing utility, at a command prompt, type

snatrace

See Note About Starting snatrace Remotely.

The SNA Server Trace Options dialog box appears.

2	In the Service name box, select a name from the list:

Service name	Kind of activity traced
SNA Applications	Activity generated by applications that use SNA APIs
SNA Server Admin	Activity generated by the SNA Server Admin interface
SnaBase	Activity generated by the SNA base, which maintains lists of service names and statuses
SnaServer	Activity generated as the local SNA Server (PU 2.1 node) interacts with clients and other nodes on the SNA network
Name of link service(s) specified during setup	Activity between a link service and other software components
For information about how the listed service names relate to types of tracing, see Types of Tracing.

3	Under Internal Tracing, drag the scroll box to the desired level of internal tracing for the selected service.

Internal tracing is intended for the use of product support technicians. Interpreting internal traces requires a special knowledge base. If a product support technical requests internal tracing, the level needed is generally Full Tracing.

Disabling internal tracing does not disable other tracing options.

4	If message tracing is available for the selected service, select appropriate options:

To enable or modify message tracing, specify the intended trace options. For more information, see the listing for the selected service under "Trace Options" in Contents for SNA Server Tracing Help.

To disable message tracing, or to clear existing options from the dialog box, choose Clear.

5	If the selected service is SNA Applications, select options for API tracing:

To enable or modify API tracing, specify the intended trace options. For more information, see SNA Applications: Client API Tracing.

To disable API tracing, or to clear existing options from the dialog box, choose Clear.

6	Select or clear the Minimize Disk Access by Buffering Writes check box. See Choosing a Buffering Option.

7	Repeat steps 2-6 for each service that you want to trace.

8	Choose OK.

SNA Server trace files are created in the TRACES subdirectory of the SNA Server root directory, with the filename extension TRC.


Note About Starting snatrace Remotely

On an SNA server, you can start the snatrace utility remotely by typing

snatrace \\servername

For servername, substitute the name of the server for which you want trace files. You can also start snatrace locally or remotely through SNA Server Admin; for information, see the Microsoft SNA Server Administration Guide.

On a Windows NT-based client, the snatrace utility can only be started locally.


Choose between the following:

To minimize the writing of trace information to disk, and instead cause the information to be held in a memory buffer until it is efficient to write it to disk, select this box.  This avoids unnecessary slowing of the system, but does not protect trace information from being lost if the system goes down.

To cause trace information to be written to disk as soon as it is generated, clear this box. This slows the system, but ensures that trace information is not lost if the system goes down.


SNA Applications: Message Traces

Trace option	Activity traced for SNA Applications  on the local system
Admin Messages	Messages between SNA Server Admin (considered as an "application"), and SnaBase and SnaServer (PU 2.1 node)
3270 Messages	Messages between 3270 applications (3270 emulators and/or LUA programs) on the local system and the SnaServer (PU 2.1 node)
LU 6.2 Messages	Messages between the APPC DLL on the local system and the SnaServer (PU 2.1 node)


SNA Applications: Client API Tracing

Trace option	Activity traced for SNA Applications
APPC API	Activity between APPC applications and the APPC DLL on the SNA server
CPI-C API	Activity between CPI-C applications and the  CPI-C DLL on the SNA server
LUA API	Activity between LUA/SLI and LUA/RUI applications and the LUA DLL on the SNA server
CSV API	Activity between CSV applications and the CSV DLL on the SNA server


SnaServer (PU 2.1 Node) Trace Options

Trace option	Activity traced for the SnaServer  (PU 2.1 node)
Admin Messages	Messages between the SnaServer (PU 2.1 node) and SNA Server Admin.
3270 Messages	Messages between the SnaServer (PU 2.1 node) and all 3270 clients (3270 emulators and/or LUA programs).
Data Link Control	Messages between the SnaServer (PU 2.1 node) and link services.
SNA Formats	Data link control messages that are in SNA formats. Such messages require a knowledge of SNA formats and protocols in order to be understood.
LU 6.2 Messages	Messages between the SnaServer (PU 2.1 node) and the APPC DLL.


SnaBase Trace Options

Trace option	Activity traced for SnaBase
Admin Messages	Messages between the SnaBase software, which maintains lists of service names and statuses, and SNA Server Admin
3270 Messages	Messages between the SnaBase software, which maintains lists of service names and statuses, and 3270 applications (3270 emulators and/or LUA programs)
LU 6.2 Messages	Messages between the SnaBase software, which maintains lists of service names and statuses, and the APPC DLL


Link Service Trace Options

Trace option	Activity traced for the link service
Admin Messages	Messages between the link service and SNA Server Admin
Data Link Control	Activity between the link service and SnaServer (PU 2.1 node)
Level 2 Messages	Information related to Level 2 in the international standards organization (ISO) model