Trace TCP applications

You can use the quality of service (QoS) trace to work with trace functions and to view the current trace buffer.

To run the trace on the server, type TRCTCPAPP (Trace TCP/IP Application command) from a command-line interface.

Here is a sample of the trace selections to complete:

TCP/IP application...........> *QOS
Trace option setting.........> *ON
Maximum storage for trace....> *APP
Trace full action............> *WRAP
Argument lists...............> 'lvl=4'
QoS trace type...............> *ALL

The following table introduces the possible parameters to use in a trace. If a setting does not appear on the character-based interface, you must enter it in a command. For example, TRCTCPAPP APP(*QOS) MAXSTG(1000) TRCFULL(*STOPTRC) ARGLIST('l=4 c=i').

Settings Options
TCP/IP application QOS
Trace option setting *ON, *OFF, *END, *CHK
Maximum storage for trace (MAXSTG) 1-16000, *APP
Trace full action (TRCFULL) *WRAP, *STOPTRC
Argument lists (ARGLIST) Levels: 'lvl=1', 'lvl=2', 'lvl=3', 'lvl=4' Content: 'c=a', 'c=i', 'c=d' , 'c=m'
QoS trace type *ALL

Maximum storage for trace

1-16000
This is the maximum storage size for the trace data. The trace either stops or wraps when this size is reached. The default size is 4MB. To specify the default size, select *APP.
*APP
This is the default option. It tells the application to use its default trace size. The default trace size for the QoS server is 4MB.

Trace full action

*WRAP
Wraps the trace information when the trace reaches the maximum disk space (trace buffer size). Wrapping will allow the system to overwrite the oldest information in the file, so you continue recording the trace information. If you do not select wrap, then the trace operation stops when the disk is full.
*STOPTRC
Stops collecting information when the system reaches maximum disk space.

Argument lists

Specifies which error levels and content will be logged. There are two arguments allowed in the TRCTCPAPP command: trace level and trace content. When you specify the trace level and trace content, make sure all attributes are contained in a single set of quotations. For example, TRCTCPAPP 'l=4 c=a'

Note: Log levels are inclusive. This means that when you select a log level, all previous log levels are also selected. For example, if you select level 3, then levels 1 and 2 are automatically included. In a typical trace, it is recommended you specify 'l=4'.

Trace levels

Level 1: System errors (SYSERR)
Logs errors that occur in systems operations. If this error occurs, the QoS server cannot continue. For example, a system error might occur if you are running out of system memory or if your system cannot communicate with TCP/IP. This is the default level.
Level 2: Errors between objects (OBJERR)
Logs errors that occur within the QoS server code. For example, an object error might occur because a server operation encounters some unexpected result. This is generally a serious condition that must be reported to service.
Level 3: Specific Events (EVENT)
Logs any QoS operation that has occurred. For example, an event log records commands and requests. The results are similar to the QoS journaling function.
Level 4: Trace messages (TRACE)
Traces all data being transferred to and from the QoS server. For example, you might use this high-level trace for logging anything that you think might be helpful for debugging problems. This information is helpful to determine where a problem occurred and how to reproduce the problem.

Trace content

Only specify one content type. If you do not specify what content to trace, then (by default) all content will be traced.

Content = All ('c=a')
Traces all functions of the QoS server. This is the default value.
Content = Intserv ('c=i')
Traces the IntServ operations only. Use this if you determine the problem to be IntServ related.
Content = Diffserv ('c=d')
Traces the DiffServ operations only. Use this if you determine the problem to be DiffServ related.
Content = Monitor ('c=m')
Traces the monitor operations only.

If you need help interpreting the trace output, read the trace output example on the trace output page, which contains sample output with comments to help you interpret its meaning. The TRCTCPAPP function is typically used by the service, so if you have problems reading the output, you might contact your service representative.

Related reference
TRCTCPAPP (Trace TCP/IP Application) Command Description