System Description › SMF Logstream Dump Processing › Logstream Dump Process User Exit

Logstream Dump Process User Exit

This exit has two purposes:

• It can alter the command that is going to be issued by the IEFU29L exit intercept. This way the command to start the automated dump procedure will be tailored to your data center's needs.

  Note: If the command length is altered, you are responsible for changing the value of the last byte of the command to be issued in the parameter list.

• It can be used to suppress some or all of the START commands that will be issued through the use of return codes.

This exit lets you tailor the command that will be issued to the system to initiate automatic SMF logstream dump processing. The exit is invoked in AMODE 31, and must remain in AMODE 31 for the entire time of operation. The exit follows typical z/OS linkage for entry and return.

The following registers are meaningful on entry to the routines:

R13

Calling Save Area. The calling registers must be saved here and restored from here upon return, with the exceptions noted below.

R14

Return Address. The address to branch to when exit processing is completed.

Note: The AMODE is not set in the address, and return should be done with a BR R14 instruction.

R15

The Entry Address. This is the address of the exit.

R1

Four Fullword Parameter List:

Register 1 points to this four-word parameter list:

+0

Address of the first byte of the command to be issued. The command is:

S CASFDUML,LS=logstream.name

+4

Address of the last byte of the command to be issued. If the command is altered by the exit and the length changes, it is the responsibility of the exit to update the value of this parameter with the new address of the last byte of the command.

+8

Address of the last byte of the command buffer (in case you wish to lengthen the command.)

+C

A 256 byte work area for the exit's use. It is expected, but not required, that the exit will use this as a save area and work area.

The return codes are as follows:

Note: If a return code is not listed, follow the directions for return code 0.

0

Issue the command that is in the buffer

4

Do not issue the command in the buffer, but call with the next logstream name, if any.

8

Do not issue the command in the buffer, and do not call the exit again.

12

Issue the command in the buffer, and do not call the exit again.

16

Terminate intercept processing. The exit will not be called again, and no further START commands will be issued for any subsequent logstreams

Note: If a return code of 8 or 12 is set, a START command will be issued to initiate automated dump processing for all remaining active logstreams that have not yet been processed by the intercept. If you do not want to have any more commands issued, you must use a return code of 16.

A sample exit named SMFLSTBL is provided in the CASFSRC library. The sample can be used as is, or it can be modified as needed. Once you have constructed the exit, it must be assembled, linked, and placed into a link list library (see LSTBLAL sample JCL). To activate the exit, modify the PARM settings for automated dumping as indicated in the CASFRIMP sample from “ENABLE” to “ENABLELS,LX=(exitname).”