Allocating Traces

You can allocate all or any combination of traces during your session or in batch. You can display the results online or store them in a file or sequential data set.

Tip: The trace facilities are intended for use in query optimization and problem debugging. Application programs should not be written to depend on the format or content of any trace, as they may change in later releases.

Syntax: How to Allocate a Trace Online

You can store trace information in an MVS sequential data set or CMS file, or you can display it online at the terminal. To capture trace data, issue the appropriate command from the command level. For example, to allocate ddname FSTRACE, issue one of the following commands:

{MVS|TSO} ALLOC F(ddname) DA('userid.FSTRACE') SHR REU 

or

DYNAM ALLOC DD FSTRACE DATASET userid.FSTRACE SHR REUSE 

or:

CMS FILEDEF FSTRACE DISK FSTRACE DATA A  

Note: DCB attributes are LRECL=80 and RECFM=F.

To view the trace information, use the system editor or the FOCUS TED editor.

To display trace data at the terminal, issue the appropriate command from the command level

{MVS|TSO} ALLOC F(FSTRACE) DA(*) 

or

DYNAM ALLOC FILE FSTRACE DA *

or:

CMS FILEDEF FSTRACE TERMINAL 

Syntax: How to Allocate a Trace in Batch

You can write trace results to SYSOUT. BLKSIZE information is optional, but should be compatible with other FSTRACE formats. For example, to allocate ddname FSTRACE:

//FSTRACE   DD   SYSOUT=*,DCB=(LRECL=80,BLKSIZE=80,RECFM=F)

You can also write trace results to an MVS sequential data set. First, allocate the FSTRACE data set in a prior batch step (as shown) or in ISPF:

//ALLOC    EXEC PGM=IEFBR14
//FSTRACE  DD   DISP=(,CATLG),DSN=userid.FSTRACE,
//         UNIT=SYSDA,VOL=SER=USERM1,SPACE=(TRK,(5,5)),
//         DCB=(LRECL=80,BLKSIZE=80,RECFM=F)
                      .
                      .
                      .

Then, allocate the trace data set with DISP=MOD in the batch FOCUS JCL:

                      .
                      .
                      .
//FOCBATCH EXEC PGM=FOCUS
//FSTRACE  DD   DISP=(MOD,KEEP,KEEP),DSN=userid.FSTRACE

Syntax: How to Free Trace Allocations

To disable a data adapter trace, clear the associated allocation

{MVS|TSO} FREE F(ddname)

or

DYNAM FREE FILE ddname

or

CMS FILEDEF ddname CLEAR

where:

ddname

Is the ddname associated with the trace, by default either FSTRACE or FSTRACEP.