Validating and maintaining your SMF mapping libraries

This section provides information on the following topics:

• Validating an SMF record layout
• Updating a layout’s source
• Maintaining XREFs
• Coding your own user layouts.

Validating an SMF Record Layout

For most record types, the last field mapped should be the last data field in the record. Scrolling DOWN (PF8) to the end of the formatted display for a layout should reveal an information line like the following:

If the information line does not say BOTTOM OF DATA, then there is probably a difference between the release level of z/OS or JES running at the time the SMF records were written, and the documentation used by Compuware to create the PL/I layout for a given record type.

If the SMF records were generated by an older system, there may be new fields defined for z/OS contained in the layout. Since these new fields don’t exist in the data, the information line at the end of the data might say:

In the case where the layout is longer than the data, there is probably no corrective action necessary. The extra layout fields are probably present to reflect future z/OS SMF record contents.

Many SMF records contain self-defining fields that can be examined to locate differences between your current version of actual SMF data records and the Compuware-supplied SMF record PL/I layouts. These self-defining fields are called “triplets”, and a triplet is present for each possible following section of fields. Each triplet consists of three binary values: a section offset, a section length, and a section count.

The value of a section offset triplet field should match the displayed offset (SHOW OFFSET, OFFSET RELATIVE) of the first layout field in the referenced section, as shown in Using Self-Defining “Triplet” to Verify Layout Accuracy. Remember, when viewing “offline” data, offsets will differ by 4. For an offline record, the triplet offset data value of a section is 4 bytes greater than the relative location of the section’s fields.

Updating a Layout’s Source

When a change is required to one of the supplied PL/I layouts, complete the following steps:

1. Use ISPF edit to update the PL/I library.
2. Insert new fields or comment out extra fields as needed. When removing extra fields, use the following PL/I coding syntax:
   /* (start comment)
   */ (end comment)
3. Be sure to make the same changes to both the SMFxxx (offline) and SMNxxx (online) members.
4. After your editing changes are completed, you can use the record layout.

Maintaining XREFs

If any XREF member changes are needed, use the XREF function, File-AID option 7, to edit existing XREF members and to create new ones.

Coding Your Own User Layouts

You may use the supplied PL/I layouts of SMF records and the examples provided by the supplied XREFs to create your own layouts and XREFs for data files such as:

• CICS journals
• DB2 logs
• IMS logs
• User SMF records.

Using Self-Defining “Triplet” to Verify Layout Accuracy