GTF creates trace records for each system event you select when
requesting GTF tracing. The header portion of system data records
for events is shown in Figure 1. Individual
event record formats The format of individual system data records
are shown in Unformatted trace records for events in alphabetical order.
Note that this section does not include all system events.
Figure 1. Header
for Unformatted System trace record Format┌──────┬─────┬─────┬─────┬──────────┬─────┬──────────┐
│length│ res │ AID │ FID │time stamp│ EID │ SID │ ... data ...
└──┬───┴──┬──┴──┬──┴──┬──┴────┬─────┴──┬──┴────┬─────┘
2 2 1 1 8 2 2
bytes bytes byte byte bytes bytes bytes
(optional)
The fields in the record contain the following information:
- length
- Total length of the record, in bytes.
- res
- Two bytes of zeros. Reserved for IBM® use.
- AID
- Application identifier, which is always X'FF' for system
data records.
- FID
- Format identifier of the routine that will format the trace record.
- time stamp
- Time stamp showing the eight-byte Greenwich mean time (GMT) when
the record was created.
- EID
- Event identifier, which identifies the event that produced the
trace record.
- SID
- System identifier, which identifies the system where the record
was produced. The SID field contains zeros when the record is a split
record. This 2-byte field is only created when GTF trace data from
multiple systems was merged using the IPCS COPYTRC command. When
present, the SID is an array index you can use to locate the source
descriptor information for a particular system. For example, if the
SID value for a record is 3, the source descriptor information for
the system issuing the record is the third source descriptor in the
control record.
To check to see whether trace data for a block
of output comes from multiple systems, look in the control record
for the options field and see if the GTWCFSID bit is set on.
See Control records for the options field.
- data
- Trace data gathered for the requested event. The length of this
field varies according to the event being traced. The data portions
for individual system trace records are shown starting on Unformatted trace records for events.