Overview of WebLogic Logging Services

The WebLogic Server logging services include facilities for writing, viewing, and listening for log messages. While WebLogic Server subsystems use these services to provide information about events such as the deployment of new applications or the failure of one or more subsystems, your application can also use them to communicate its status and respond to specific events. For example, you can use WebLogic logging services to keep a record of which user invokes specific application components, to report error conditions, or to help debug your application before releasing it to a production environment. In addition, you can configure your application to listen for a log message from a specific subsystem and to respond appropriately.

Because each WebLogic Server administration domain can run concurrent, multiple instances of WebLogic Server, the logging services collect messages that are generated on multiple server instances into a single, domain-wide message log. You can use this domain-wide message log to see the overall status of the domain.

To provide this overview of a domain's status, each WebLogic Server instance uses embedded Java Management Extensions (JMX) facilities to broadcast the messages that are in its log files. The broadcast includes all messages that subsystems and applications generate, except for special debug messages that your application can generate. The Administration Server listens for these notifications and writes a subset of them to the domain-wide log file. (See Figure 1-1.)

Figure 1-1 WebLogic Server Logging Services

 

The remainder of this document describes how your application can write and listen for messages, and how you can view them through the WebLogic Server Administration Console.