Logging Configuration

There are two ways of configuring Log4j in WSO2 Carbon. Either by manually editing the log4j.properties file or through the management console. Changes you made to Log4j configuration through the management console are persisted in WSO2 Registry. Therefore, those changes will be available after the server restarts. There is also an option to restore the original Log4j configuration from the log4j.properties file using the management console. But if you modify the log4j.properties file and restart the server, you will see the changes you have made. That means the earlier log4j configuration persisted in the registry is overwritten.

Follow the instructions below to set up logging.

1. Log on to the Gadget Server Management Console.

2. Click the "Configure" menu and select "Logging."

3. The "Logging Configuration" window appears.

4. The "Logging Configuration" window has three sections:

• Global Log4J Configuration
• Configure Log4J Appenders
• Configure Log4J Loggers

Using these sections, you can configure the layout and the amount of information about the system activity you want to receive.

Global Log4J Configuration

This section allows you to assign a single log level and log pattern to all loggers.

• Log Level - Reflects a minimum level that this logger cares about. You can view the hierarchy of levels below.
• Log Pattern - Defines the output format of the log file.

Configure Log4J Appenders

This section allows you to configure appenders. Log4j allows logging requests to print to multiple destinations. These output destinations are called "Appenders." You can attach several appenders to one logger.

• Name -The name of an appender. By default, WSO2 Gadget Server comes with the following log appenders configured:** CARBON_CONSOLE - Logs to the console when the server is running.
  • CARBON_LOGFILE - Writes the logs to AS_HOME/repository/logs/wso2carbon.log.
  • CARBON_MEMORY
  • CARBON_SYS_LOG - Allows separation of the software that generates messages from the system that stores them and the software that reports and analyzes them.
  • CARBON_TRACE_LOGFILE

• Log pattern - Defines the output format and layout of the log file that is created.

• Threshold - Filters log entries based on their level. For example, threshold set to "WARN" will allow log entry to pass into appender if its level is "WARN," "ERROR" or "FATAL," other entries will be discarded.

The Available Categories of Logs you can View are:

• TRACE - Designates fine-grained informational events than the DEBUG.
• DEBUG - Designates fine-grained informational events that are most useful to debug an application.
• INFO - Designates informational messages that highlight the progress of the application at coarse-grained level.
• WARN - Designates potentially harmful situations.
• ERROR - Designates error events that might still allow the application to continue running.
• FATAL - Designates very severe error events that will presumably lead the application to abort.

Configure Log4J Loggers

This section allows you to browse through all loggers and define a log level and switch on/off additivity to any of them.

• Logger - The name of a logger.
• Parent Logger - The name of a parent logger.
• Level - Allows to select level (threshold) from the drop-down menu. After you specify the level for a certain logger, a log request for that logger will only be enabled if its level is equal or higher to the logger’s one. If a given logger is not assigned a level, then it inherits one from its closest ancestor with an assigned level. The Log Level is the same as the Threshold list in Loggers above, in name and function.
• Additivity - Allows to inherit all the appenders of the parent Logger if set as "True."