Logging is one of your most important troubleshooting tools. It is the process by which GlassFish Server captures data about events that occur during server operation, such as configuration errors, security failures, or server malfunction. This data is recorded in a log file, and is usually your first source of information when Enterprise Server problems occur. The primary purpose of log files is to provide troubleshooting information. Analyzing the log files can help determine the health of the server and identify problem areas.
By default all GlassFish Server log information is captured in the server.log file, typically located in domain-dir/logs. You can view logging information by using the Administration Console or the asadmin utility. You can also open the server.log file in a text editor and search for the module that you are interested in.
For information about using the Administration Console log viewer and logging functions, see the Administration Console online help. For information about viewing logging information from the command line, see Viewing Log Information in Oracle GlassFish Server 3.0.1 Administration Guide.
Logging is configured by editing the logging.properties file, located by default in the same directory as the domain.xml file, typically domain-dir/config. Logging can also be configured using the Administration Console.
Log levels such as SEVERE, WARNING, INFO, CONFIG, and others can be set to provide different types and amounts of information. The default setting is INFO. Each GlassFish Server module has its own logger, and each logger has its own namespace. Log levels can be set globally for all loggers, or individually for module-specific loggers.
For complete details about logging see Chapter 7, Administering the Logging Service, in Oracle GlassFish Server 3.0.1 Administration Guide.