Pathway/XM System Management Manual

Managing a Pathway/XM Environment
Compaq NonStop™ Pathway/XM System Management Manual—426761-001
7-10
Specifying the Location for Message Logging
once they scroll off the terminal screen; also, performance is generally better to a
process on a disk file than to a terminal.
The file used initially for message logging, before either of the LOG1 or the LOG2
commands has been specified, is the EMS central event log file, $0. If multiple
Pathway/XM environments reside on a physical (Expand) node, all the Pathway/XM
environments initially log to the same $0 file. Each log message identifies the process
that created it.
To select a destination other than $0 for logging messages, or to specify two destinations
for messages, you use the PXMCOM commands LOG1 and LOG2. For example, to
specify $0 as the log file for errors reported in tokenized event-message format, and to
specify the disk file LOGCOPY as a log file for both error and status change
information in text format, enter:
>> LOG1 $0, EVENTFORMAT
>> LOG2 LOGCOPY, STATUS
Before specifying a disk file other than $0 for logging, you must first create a file with
that name. It is recommended that you use the TACL FUP CREATE command to
create an unstructured file of type 0. (You should ensure that the file is of sufficient
size.) See the LOG1 and LOG2 commands for more information.
PXMCOM records the log file names that you select in the SuperCTL file. After a cool
start or a warm start, the same log files are used again; records produced after the cool
start or warm start are appended to these files.
If an error occurs while error information, status information, or both are being written
to a log file other than $0, the affected process does the following:
1. Closes the log file specified with the file-name parameter.
2. Opens $0.
3. Writes the information to $0. The process writes error information, status
information, or both to $0, depending on what was specified for the initial log file
with the STATUS parameter. Additionally, the process writes the information to $0
in the same format (that is, event messages or text) specified for the initial log file
with the EVENTFORMAT parameter.
If an error then occurs while a Pathway/XM process is writing information to $0, the
process closes $0 and prohibits further error and status logging. The process does not
reopen either the log file or $0.
In the following example, you have configured two log files:
>> LOG1 $0, EVENTFORMAT
>> LOG2 $DATA.PM.LOGFILE, STATUS
If an error occurs on LOG1, the process closes the log because the error occurred on $0;
the process would not reopen LOG1. If an error occurs on LOG2, the process reopens
Caution. If you log information to a terminal, Compaq recommends restricting activity on that
terminal. If the terminal is busy it can cause the Pathway/XM environment to become
suspended while waiting to log messages.