TS/MP 2.5 Management Programming Manual

Log File Error Recovery
While your Pathway subsystem is running, the PATHMON process and the Pathway/iTS TCPs
report errors and status information to a log file. Using the fields associated with ZLOG1INFO and
ZLOG2INFO, you can direct the PATHMON process to report errors only, or errors and changes
in object status as well. You can direct the PATHMON process to log information to only one file
or to copy the information to two files. Also you can request that this error and status information
be formatted either as text or as event messages. For more information about TCPs, see the
Pathway/iTS System Management Manual.
If an error occurs while error information, status information, or both are being written to a log
file, the PATHMON process:
1. Closes the log file specified with the ZFILE field.
2. Opens $0 (a collector process provided with TS/MP).
3. Writes the information to $0. The PATHMON process writes error information, status
information, or both to $0 depending on what was specified for the initial log file with the
ZSTATUS field. Additionally, the PATHMON process writes the information to $0 in the same
format (that is, event messages or text) specified for the initial log file with the ZEVENTFORMAT
field.
If an error then occurs while information is being written to $0, the PATHMON process closes $0
and prohibits further error and status logging. The PATHMON process does not reopen either the
log file or $0.
In this example, you have configured two log files:
LOG1 $0, EVENTFORMAT
LOG2 $DATA.PM.LOGFILE, STATUS
If an error occurs in LOG1, the PATHMON process closes the log because the error occurred on
$0; PATHMON process does not reopen LOG1. If an error occurs on LOG2, the PATHMON
process reopens $DATA.PM.LOGFILE as LOG2 $0, STATUS. The PATHMON process then sends
both error information and status information to $0, because LOG1 used the default value
(ZPWY-VAL-OFF) for ZSTATUS and LOG2 specified ZPWY-VAL-ON for ZSTATUS. Additionally,
PATHMON process now sends both event messages and text messages to $0, because LOG1
specified ZPWY-VAL-ON for ZEVENTFORMAT and LOG2 used the default value (ZPWY-VAL-OFF)
for ZEVENTFORMAT.
Considerations
• The CONTROL PM command encompasses the functions of the ALTER PATHMON, CONTROL
PATHMON, LOG1, and LOG2 commands in the PATHCOM interface.
• If the CPU you specify for the ZBACKUPCPU field is the CPU where the PATHMON primary
process is running, the PATHMON process returns the error:
*1095* ILLEGAL CPU NUMBER
and does not change the location of its backup process.
If the CPU you specify for ZBACKUPCPU is a CPU that does not exist or that is not operational,
the PATHMON process returns the error:
*1093* BACKUP PROCESSOR DOWN
The PATHMON process also returns this error if you specify a backup CPU and your system
is a single-processor system.
• If the primary PATHMON process is running in the CPU defined for the backup PATHMON
process because of a SWITCH command or some other processor change, the ZBACKUPCPU
option causes the PATHMON process to change the PATHMON configuration file so that it
contains the current CPU numbers for both the primary and backup PATHMON processes.
118 Pathway Subsystem Control Commands