Setting Up CTRACE › How to Enable CTRACE

How to Enable CTRACE

To enable CTRACE

1. Create an external writer.
2. Verify the Setup.

Create an External Writer

CTRACE collects trace data from your server. For packet tracing to work, you need to create source JCL that invokes a CTRACE external writer. The external writer is used to write trace data to a data set each time packet tracing is used.

The external writer must use only single data sets for recording trace data. This is because CA NetMaster NM for TCP/IP reads only one trace data set.

To create an external writer

1. Edit the following example JCL to suit your specific requirements. The JCL procedure should be added to your SYS1.PROCLIB system library.

   //PTTCP PROC
   //*
   //* CTRACE External writer for TCP/IP Packet Tracing
   //*
   //IEPROC EXEC PGM=ITTTRCWR,TIME=1440
   //*
   //*TRCOUT01 DD DSN=TCPIP.PTRACE.PTRACE,DISP=OLD
   //
   //TRCOUT01 DD DSN=TCPIP.PTTRACE.PTRACE,DISP=(NEW,CATLG),
   //            VOL=SER=????,UNIT=SYSDA,DSORG=PS,
   //            SPACE=(4096,(100,10))
   

   PTTCP is the name of the external writer. You can change this to suit your installation; it must be between one and seven characters long.

   Do one of the following:

   • Create a trace data set with the attributes DSORG=PS, RECFM=27994, and LRECL=VB.
   • Leave DSORG, RECFM, and LRECL unspecified and allow the program to determine their values.

   After the trace data set is allocated, do one of the following:

   • Modify the JCL so that TRCOUT01 is specified with DISP=OLD.
   • Delete or rename the TRCOUT01 data set before rerunning the procedure.
2. Determine the command that you are going to use to start the CTRACE external writer. You must specify this command on the CTRACE panel when you start CTRACE for the first time from your region. For example:

   TRACE CT,WTRSTART=PTTCP,NOWRAP

   where:

   • TRACE is the MVS TRACE command.
   • CT indicates that it is a component trace.
   • PTTCP is the name of the external writer that you specified in Step 1.

   For more information, see the IBM's MVS Diagnosis: Tools and Service Aids guide.

Verify the Setup

To verify the setup, you must start a CTRACE trace.

To start a trace

1. Enter /CTRACE at the prompt.

   The CTRACE Packet Tracing Menu appears.

2. Enter PT at the prompt.

   The Start CTRACE panel appears.

3. Complete the following field:

   Command to Start CTRACE

   Specifies the command to use to start CTRACE.

4. Press F6 (Action).

   The trace starts.

To stop a trace

1. Enter /CTRACE at the prompt.

   The CTRACE Packet Tracing Menu appears.

2. Enter PTC at the prompt.

   The Confirm Trace Stop panel appears.

3. Press F6 (Confirm).

   The trace stops.