Logging and Internationalization

WebLogic's logging infrastructure plays an important role in the administration and management of a domain. Every important subsystem within WebLogic supports the logging framework, sending informational, warning, and error notifications. These notifications can help you understand the state of a server instance and its subsystems, and are critical when handling any errors and failures. These notifications are made easier because of the distributed nature of WebLogic's logging architecture, which allows it to be managed centrally. This chapter begins by looking at how the logging architecture is distributed throughout a WebLogic domain and at how the separate server logs eventually combine into a domain log on the Administration Server. We'll also look at how to access the various log files and interpret them so that you can detect errors and the source of these errors.

The logging architecture in WebLogic 8.1 is implemented using a combination of WebLogic's JMX services and the JDK 1.4 logging API, making it a perfect partner to the management and control facilities provided by the JMX framework. Indeed, we describe how to use the JMX services to write your own applications that listen for log events, allowing you to create powerful management applications that can react to critical notifications. We also show you how to manipulate logging by writing standard log handlers and filters.

Two important features of the logging architecture are its extensibility and support for internationalization. We show you how to create your own catalog of log messages, and how to use WebLogic-supplied tools to automatically generate Java classes that can be used within your own code. This makes it very easy to instrument your own applications. The log messages generated from your applications fit in seamlessly with the internally generated log messages, thereby ensuring that your code can take full advantage of the distributed logging architecture. The log message catalogs that you create can be written in any language and can be accompanied by translations for different locales. The built-in support for internationalization ensures that the log messages are presented in the appropriate language for the current locale under which WebLogic is running.