Self-defining sections

A self-defining section of an SMF record tells you where to find an accounting record, how long it is, and how many times that type of record is repeated (with different values). The self-defining sections follow the header, at a fixed offset from the start of the SMF record.

Each self-defining section points to accounting related data. Table 21 summarizes the offsets from the start of the SMF record header.

Table 21. Offsets to self-defining sections Offsets are from the start of the SMF record and are fixed for each type of accounting source.
Record subtype (SMF116STF)	Source of accounting data	Offset of self-defining section	See...
All	Common header	28	X'1C'	Common WebSphere MQ SMF header

Note:

Other self-defining sections refer to data for IBM use only.

Each self-defining section is two fullwords long and has this format:

   ssssssssllllnnnn

where:

ssssssss: Fullword containing the offset from start of the SMF record.
llll: Halfword giving the length of this data record.
nnnn: Halfword giving the number of data records in this SMF record.

Figure 21 shows an example of part of an SMF type 116 record. The numbers in the left-hand column represent the offset, in hexadecimal, from the start of the record. Each line corresponds to sixteen bytes of data, where each byte is two hexadecimal characters, for example 0C. The characters in the right-hand column represent the printable characters for each byte. Non-printable characters are shown by a period (.) character.

In this example, alternate fields in the SMF header are underlined to help you to see them; refer to Table 20 to identify them. The self defining section for one of the message manager accounting data records (at the offset given in Table 21) is shown in bold.

Figure 21. Part of an SMF record 116 showing the header and self-defining sections

000000 01A40000 5E740035 61240100 223FD4E5  *....;.../.....MV*
000000 F4F1D4D8 F0F70000 F6F0F000 00000134  *41MQ07..600.....*
000000 00700001 00000054 00B00001 00000104  *................*
000000 00300001 00000000 00000000 00000000  *................*
000000 00000000 00000000 00000000 00000000  *................*

The self-defining section for the type of message manager accounting data is located at offset X'2C' from the start of the SMF record and contains this information:

The offset of the message manager accounting data is located X'00000104' bytes from the start of the SMF record.
This message manager record is X'0030' bytes long.
There is one record (X'0001').

Note:

Always use offsets in the self-defining sections to locate the accounting records.

1	Thread identification record	36	X'24'	Thread-level and queue-level data records
1	Thread-level accounting	44	X'2C'	Thread-level and queue-level data records
1	Queue-level accounting	52	X'34'	Thread-level and queue-level data records. This section is present only if the WTASWQCT field in the task-related information (WTAS) structure (Table 25) is non-zero.

2	Thread identification record	36	X'24'	Thread-level and queue-level data records
2	Queue-level accounting	44	X'2C'	Thread-level and queue-level data records