TS/MP Management Programming Manual (G06.24+, H06.03+)

Event Management
NonStop TS/MP Management Programming Manual—540082-001
10-5
Error Lists and Error Recovery
Error Lists and Error Recovery
Pathway subsystem event messages do not contain error lists to describe errors
reported by other subsystems. These errors are indicated by simple tokens. For
example, when the PATHMON process reports a file system I/O error (such as ZPWY-
ERR-PM-PATHCTLIO), the error value is reported in the token ZPWY-TKN-ERROR.
If an error occurs while error or status information is being written to a log file, the
PATHMON process:
1. Closes the log file specified with the ZFILE option.
2. Opens $0 (a collector process provided with the Pathway subsystem).
3. Writes the information to $0. 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, 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.
This example commands configure two log files:
LOG1 $0, EVENTFORMAT
LOG2 $DATA.PM.LOGFILE, STATUS
If an error occurs on 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, the PATHMON process 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.
Message Filters
EMS provides you with the capability to create programs called filters, which allow
applications to select particular event messages from among all the event messages
that have been issued. Filters select event messages to be returned to an application
by examining the values of tokens in the event message.
Any of the tokens in an event message can be used for selecting the event messages
to be returned to an application. You can create filters that return all event messages
issued during a particular time period, all event messages with a certain event number,
all event messages associated with a particular CPU, and so forth.
When designing event-message filters, consider: