Java virtual machine log files

The Java virtual machine (JVM) log files contain the output for the System.out and System.err output streams for the application server process. One log file is created for the System.out output stream and another for the System.err output stream. The JVM logs contain print data written by applications. The data may be written directly by the application in the form of System.out.println(), System.err.print(), or other method calls. Data may also be written indirectly by the application calling a JVM function, such as Exception.printStackTrace(). In addition, the System.out JVM log contains system messages, also known as message events, written by the application server.

The JVM log files are self-managing. The maximum file size and the number of log files to archive and when to archive log files are user defined.

The log files must have the following granted authorities:

• *Public *Exclude
• QEJBSVR *RW

If the application server is running under a user profile other than the default (QEJBSVR) and the user profile does not have QEJBSVR specified as a group profile, the user profile must have explicit *RW authority to the JVM log file.

Application print data may be formatted with the JVM to display as a WebSphere system message or as plain text. WebSphere system messages are always preformatted.

See these topics for information on how to use the JVM log files:

• Configure the Java virtual machine log files
  Learn how to configure the JVM log files for your application server through the administrative console .

• View the Java virtual machine log files
  Learn how to view the JVM log files through the administrative console and other methods.

• Interpret the contents for the Java virtual machine log files
  Learn about the formatting of the information contained in the log files.