Unformatted lost event records

A lost event record indicates that GTF lost the trace records for one or more events because of an error or overflow of the trace buffer. Figure 1 shows the format of a lost event record.

Figure 1. Unformatted Lost Event Record

┌──────┬─────┬─────┬─────┬─────────┬──────────┬─────┬──────────┐
│length│ res │ AID │ FID │time zone│time stamp│count│   SID    │
└──┬───┴──┬──┴──┬──┴──┬──┴────┬────┴────┬─────┴──┬──┴────┬─────┘
   2      2     1     1       4         8        4       2
 bytes  bytes  byte  byte   bytes     bytes    bytes   bytes
                                                     (optional)

The fields in the lost event record contain the following information:

length

Total length of the record, in bytes.

res

Two bytes of zeroes. Reserved for IBM® use.

AID

Application identifier, which is always zero for lost event records.

FID

Format identifier. The value of FID is one of the following:

X'02', if some trace records are missing because of an error or an overflow of the trace buffer.
X'03', if an entire block of trace records is missing because of an error or an overflow of the trace buffer.

time zone

Value showing the difference between local time and Greenwich mean time (GMT) in binary units of 1.048576 seconds when tracing began.

time stamp

Time stamp showing the eight-byte Greenwich mean time (GMT) when the control record was created.

count

If the FID is X'02', indicating that some trace records are missing, this field contains the number of trace events that are lost.

If the FID is X'03', indicating that an entire block of trace data is missing, this field contains zeros.

SID

The system identifier of the system where this trace record was created. This 2-byte field only exists 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.