A number of the Web Server subsystems create log files and log their events to these files. The primary purpose of these log files is to provide troubleshooting information.
Web Server Error Logs are the first place you should look for information, when you need to troubleshoot a runtime issue. For issues related to installation, see the installation log files.
In addition to the message text, a logged message provides the following information:
Date and time of the event
Log level for the event — Web Server-specified log level ID or name
Process identifier (PID) — PID of the Web Server process
(optional) Virtual server identifier (VSID) — VSID that generated the message
Message identifier (MID) — subsystem and a four digit integer
Message data
The specific logs associated with each Web Server problem area are discussed in the associated chapters of this manual.
The Web Server has many log levels that can be set in the Administration GUI (FINEST, FINER, FINE, CONFIG, INFO, WARNING, SEVERE, ALERT, and FATAL). All messages are logged when the log level is set to FINEST and only serious error messages appear if the log level is set to FATAL.
Note that the more detailed log levels (FINEST, FINER, FINE) can generate high volumes of log information for certain events, which may make it appear at first glance that there is an error condition when in fact there is not.
All messages with a log level less than the default level of INFO (FINEST, FINER, FINE, and CONFIG) provide information related to debugging and must be specifically enabled. Instructions for doing this are contained in the Sun Java System Web Server Administrator's Guide.
In addition to the standard JDK log levels, the Web Server has added log levels designed to map more intuitively to the Web Server log file (server.log) and to tightly integrate with Solaris. The log levels ALERT and FATAL are specific to the Web Server and are not implemented in the JDK1.4 logging API.
For information on the event log mechanism used in the Microsoft Windows operating environment, refer to the Windows help system index using the keywords Event Logging. If you choose to send logs to the Windows server.log file, only messages with a log level of INFO, WARNING, SEVERE, ALERT, or FATAL are logged to the Windows Event Log.
The Administration GUI provides the following two logging options:
Option 1 — Log stdout (System.out.print) content to the event log
Option 2 — Log stderr (System.err.print) content to the event log
When these options are set, stdout and stderr messages are written to the server.log file. (The event log is a syslog daemon on Solaris and Event Log on Microsoft Windows.)
If the above options are not set:
Anything written to stdout or stderr (that is, using System.out or System.err) will not appear in the logs.
Messages logged with the JDK logger will appear in the logs.
Messages written to stdout or stderr appear with the INFO level, but do not have a message ID.