Expand Configuration and Management Manual (G06.24+)

Tracing
Expand Configuration and Management Manual—523347-008
16-3
Tracing a Line in a Multi-Line Path
Tracing a Line in a Multi-Line Path
To start a trace of a line that is part of a multi-line path, enter
-> TRACE LINE $line-name, TO $file-name, SELECT ALL, WRAP
To stop the trace, enter
-> TRACE LINE $line-name, STOP
$line-name specifies the name of the line logical device. $file-name specifies the
name of the file to which the trace records will be written.
Tracing Using SCF
To trace records, you enter the SCF TRACE command using keywords to select
records (refer to TRACE Command on page 15-106 for details about your options).
This command is sent to the Expand product module that has been bound into the
SCF Kernel. The product module converts this command into the Subsystem
Programmatic Interface (SPI) format that is understood by the Subsystem Control
Process (SCP). SCP sends a response to the product module after it receives the SPI
buffer, indicating whether the command has been accepted.
If the command is accepted by SCP, SCP translates the SPI buffer into a bit mask that
it sends to the Expand manager ($ZEXP). The Expand manager sends the bit mask to
either $NCP or the line-handler process, depending on the object type specified in the
TRACE command. The $NCP or Expand line-handler process, when it receives this bit
mask, calls the SCP trace module defined within the Expand subsystem. The SCP
trace module causes the selected records to be sent to the SCP Trace Collector.
The SCP trace module in Expand continues to trace records that meet the selected
criteria until you stop the trace using the STOP keyword in the TRACE command, or
when the maximum file size has been reached and the WRAP option has not been
specified. Once you have stopped the trace, you can use the PTrace commands to
look at the records.
Enter the RUN command (explicitly or implicitly) to initiate the PTrace facility. Once
initiated, enter the FROM command, which causes the Expand product module in
PTrace to send an OPEN to the disk file specified. You can then use several of the
PTrace commands (such as RECORD, NEXT, and FIND) to send the records from the
disk to memory. If you have issued the FILTER or SELECT command, the Expand
product module will check each record sent from the disk file as a result of the
RECORD, NEXT, or FIND command to verify that it meets the criteria you have set
using the FILTER or SELECT command. Records that do not meet the criteria will not
be sent to the terminal or printer; the records will be discarded. The PTrace facility
does not function in block mode; it only functions in conversational mode.
Note. If you have selected the NOCOLL option in the TRACE command, the SCP Trace
Collector will not be initiated and the SCP Trace module in the Expand subsystem will send the
selected records directly to the disk file you have specified.