Monitoring the trace

Use the MVS™ DISPLAY TRACE command to check the trace options currently in effect. The following example is an example of a console showing the display command and the resulting output (the line numbers were added for discussion reference).

 1.     14.27.14  D TRACE,COMP=SYSTCPIP,SUB=(tcpiproc)             
 2.     14.27.14  IEE843I 14.27.14  TRACE DISPLAY      
 3.             SYSTEM STATUS INFORMATION                       
 4.      ST=(ON,0064K,00064K) AS=ON  BR=OFF EX=ON  MT=(ON,064K) 
 5.       TRACENAME                                             
 6.       =========                                             
 7.       SYSTCPIP                                              
 8.                           MODE BUFFER HEAD SUBS             
 9.                           =====================             
10.                           OFF         HEAD    1             
11.          NO HEAD OPTIONS                                    
12.       SUBTRACE            MODE BUFFER HEAD SUBS             
13.      -------------------------------------------------------
14.       TCPIPROC            ON   0008M                        
15.          ASIDS      *NONE*                                  
16.          JOBNAMES   EZASOKJS                                   
17.          OPTIONS    SOCKAPI                                 
18.          WRITER     CTW

For component SYSTCPIP, do not be misled by line 10 in the example. It always says the trace is off because TCP/IP uses the subtrace for all tracing. The subtrace TCPIPROC on line 14 indicates the actual state of the trace. In this example, the trace is active (ON) with an internal buffer size of eight megabytes and only the SOCKAPI option is active. Only one application (EZASOKJS) is being traced and the trace is being written to an external writer.

Line: Description
1: The MVS DISPLAY TRACE command. For more information about this command, see z/OS MVS System Commands.
2–4: These are explained in z/OS MVS System Messages, Vol 1 (ABA-AOM) for IEE843I.
5–7: Show that this is the CTRACE component SYSTCPIP.
8–11: These are not applicable for TCP/IP because TCP/IP uses only the subtrace facility of the MVS CTRACE service. Instead of activating a global trace, the trace options are specified for each stack individually. Thus, there can be multiple TCP/IP stacks with different CTRACE options. Note however that line 10 is useful — it shows that there is one subtrace (meaning one TCP/IP stack is active).
14: Shows the "subtrace" name is the TCP/IP procedure name (TCPIPROC in this example), whether the trace is active (MODE=ON), and the buffer size is eight megabytes. The buffer size is the number of bytes that is used for recording the trace.
15–16: Show the ASID and JOBNAME filtering values. If any ASIDs or JOBNAMEs are listed, only those trace entries matching the ASID or JOBNAME are collected. "ASIDS *NONE*" indicates that all address spaces are being traced (there is no filtering).
17: Shows the specific options that are active, as specified in the TRACE command or in the CTIEZBxx PARMLIB member. If port or IP address filtering were active, they would appear on this line.
18: Shows the external writer is inactive. If the writer is active, the writer procedure name is shown instead of *NONE*.