9.3 About Directing Log Output to a File or the System File

To send log output to a destination, you configure a log writer.

A log writer can send log output to one, none, or both of the following:

A log file.

This file resides under the root installation directory of the component.
The system file of the host for the component.

If more than one component resides on the same host, all components send data to the system log file on that host.

You can send logs of a particular level, or logs of different levels, to more than one type of log writer. For instance, you can send Fatal data to the system log, and send Trace data to a file. Or, you can send Fatal data to both the system log and a file.

You define log writers in the log configuration file using the LOG_WRITER parameter in a log-handler definition. See "Parameters in the WebGate Second Compound List and Log Handlers" for details.

The log writers are described in Table 9-3.

Table 9-3 Log Writers

Writer Description

Writer	Description
`SysLogWriter`	Sends data to the system log file for the computer that hosts the component being logged. Typically, the system log file contains event information from multiple applications and the host operating system. For Windows, this is the application log file located at My Computer, Manage, Event Viewer, Application. For UNIX platforms, the name and location of the system log file can vary according to the computer and the preferences of the system Administrator. Consult the Administrator of the computer for the file location. The default log configuration file sends Fatal, Error, and Warning messages to the system log file.
`FileLogWriter`	This writer is recommended when you want to save log data for an OAM Server or other single-process application on a disk file. The FileLogWriter opens the log file and holds it open for disk writes until the approximate file size limit or file rotation interval has been reached. Oracle does not recommend this log writer for situations where more than one process needs to write to the same log file. For these situations, use the MPFileLogWriter.
`MPFileLogWriter`	This writer resembles the FileLogWriter, except that it opens and closes the log file each time it writes data to the file. This enables multiple processes to write to the file in turn. However, this practice can slow performance substantially. Oracle recommends using MPFileLogWriter only when FileLogWriter fails to record logging data from some of the processes associated with a multi-process application, for example, an Access Client installed on a multi-process Web server (such as Apache) or the Solaris version of the iPlanet Web server.

SysLogWriter

Sends data to the system log file for the computer that hosts the component being logged. Typically, the system log file contains event information from multiple applications and the host operating system.

For Windows, this is the application log file located at My Computer, Manage, Event Viewer, Application.

For UNIX platforms, the name and location of the system log file can vary according to the computer and the preferences of the system Administrator. Consult the Administrator of the computer for the file location.

The default log configuration file sends Fatal, Error, and Warning messages to the system log file.

FileLogWriter

This writer is recommended when you want to save log data for an OAM Server or other single-process application on a disk file.

The FileLogWriter opens the log file and holds it open for disk writes until the approximate file size limit or file rotation interval has been reached. Oracle does not recommend this log writer for situations where more than one process needs to write to the same log file. For these situations, use the MPFileLogWriter.

MPFileLogWriter

This writer resembles the FileLogWriter, except that it opens and closes the log file each time it writes data to the file. This enables multiple processes to write to the file in turn. However, this practice can slow performance substantially.

Oracle recommends using MPFileLogWriter only when FileLogWriter fails to record logging data from some of the processes associated with a multi-process application, for example, an Access Client installed on a multi-process Web server (such as Apache) or the Solaris version of the iPlanet Web server.