Self-defining sections
Use this topic as a reference for format of the self-defining sections of the SMF record.
A self-defining section of a type 115 SMF record tells you where to find a statistics 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 fixed offsets from the start of the SMF record. Each statistics record can be identified by an eye-catcher string.
The following types of self-defining section are available to users for type 115 records. Each self-defining section points to statistics data related to one of the IBM MQ components. Table 1 summarizes the sources of the statistics, the eye-catcher strings, and the offsets of the self-defining sections from the start of the SMF record header.| Source of statistics | Record subtype (SM115STF) | Offset of self-defining section | Eye-catcher of data | |
|---|---|---|---|---|
| Dec | Hex | |||
| Storage manager | 1 | 100 | X'64' | QSST |
| Log manager | 1 | 116 | X'74' | QJST |
| Message manager | 2 | 36 | X'24' | QMST |
| Data manager | 2 | 44 | X'2C' | QIST |
| Buffer manager - one for each buffer pool, see note below | 2 | 52 | X'34' | QPST |
| Lock manager | 2 | 60 | X'3C' | QLST |
| Db2® manager | 2 | 68 | X'44' | Q5ST |
| Coupling Facility manager | 2 | 76 | X'4C' | QEST |
| Topic manager | 2 | 84 | X'54' | QTST |
| SMDS usage | 2 | 92 | X'5C' | QESD |
| Buffer manager - one for each buffer pool, see note below | 215 | 36 | X'24' | QPST |
| Channel initiator | 231 | QWSX | ||
| Data manager page set - one for each page set | 201 | 36 | X'24' | QIS1 |
- For the Buffer Manager entry in subtype 2 the self-defining section will always show zeros indicating that there are no buffer manager records.
- Other self-defining sections refer to data for IBM use only.
Buffer manager statistics go into different subtypes depending on the settings for OPMODE in the system parameters. If IBM MQ Version 8.0 new functions have been enabled with OPMODE, buffer manager statistics will go into subtype 215, and the self defining section for buffer manager statistics in subtype 2 will be all zeros. Otherwise, buffer manager statistics will go into subtype 2 and subtype 215 statistics will not be generated.
Each self-defining section is two fullwords long and has this format:ssssssssllllnnnnwhere:
| ssssssss | Fullword containing the offset from the 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. |
For more information see, Examples of SMF statistics records.
Note: Always use offsets in the self-defining sections to locate the statistics records.