Chapter 9. Logging and Statu s9.1. Logging Overview
The purpose of logging is to record events of interest that occur in HPSS in the sequence they occur to
support diagnostic research.
HPSS provides eight log message types:
•Alarm
•Event
•Status
•Debug
•Request
•Security
•Accounting
•Trace
The purpose of each of these log message types is described later in this chapter.
Log messages are deposited in four places. Certain high priority messages are transmitted to SSM and
displayed on the Alarms and Events window. This allows the administrator to see events unfoldi ng in
close to real time. All log messages are coded in a binary format and written to one of two central log
files. The Log Daemon writes these files alternatively. Also, the Log Client on each host writes a large
circular ASCII file with log messages just for that host as they are received. This file makes it easy for
the administrator to copy the file and quickly search it for an event of interest using ordinary text
processing tools. Finally, if HPSSLOGGER is set, HPSS will log to the location specified by HPSS
LOGGER (syslog or stdout) if the logger isn't running/available.
The HPSS logging facility is comprised of two types of servers, Log Clients and the Log Daemon. Log
Clients run on each HPSS node. A Log Client receives log messages from each HPSS server running on
its node and filters those messages based on the configured log policies. Messages that pass the filter are
logged locally based on the Log Client’s configuration and are then sent to the Log Daemon. The Log
Daemon checks the log policies to see which messages are to be displayed in the Alarms and Events SSM
window before entering them into the central log.
For useful logging to take place, it is important that the log policies, Log Clients and Log Daemon are all
configured and managed properly.
The HPSS logging system includes these components:
1. Log Policies (Section 9.2: Log Policies on page 295)
2. Local logs (Section 9.5 Error: Reference source not found on page 301)
3. The Central Log (Section 9.3: Managing the Central Log on page 299)
4. Log Clients and Log Daemon (Section 5.1.4: Log Client Specific Confi guration on page 100 and
Section 5.1.1: Log Daemon Specific Configuration on page 101)
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