7.4.6 -XX:[+|-]JavaLogHeaderOutput

Description

-XX:[+|-]JavaLogHeaderOutput specifies whether to output the header information when a Java VM log file is opened. The header information consists of the following: the Java VM version in the 1st line, and the startup command line information in the 2nd line. When specifying the maximum file size for the -XX:HitachiJavaLogFileSize option, you must take into account the size of the header information to be output. This option applies to Java VM log files and the log files for the explicit memory management functionality.

If the rotation type is the shift method, the Java VM log file is opened in edit mode when Java VM starts. Therefore, if Java VM starts and stops repeatedly, the log information output for each Java VM execution is written in a single Java VM log file. If this option is enabled, the time when the Java VM started can be checked in the header information, and the log information that is output for each Java VM execution can be distinguished. However, if this option is disabled, it will be difficult to distinguish the log information that is output for each Java VM execution. For this reason, we recommend that you enable this option.

Syntax

-XX:[+|-]JavaLogHeaderOutput

Specifiable values

Type: String

-XX:+JavaLogHeaderOutput

Outputs the header information when a Java VM log file is opened.

-XX:-JavaLogHeaderOutput

Does not output the header information when a Java VM log file is opened.

Default value

If the definition item is omitted:

-XX:+JavaLogHeaderOutput

[JVM]<Fri May 30 19:27:24 2014>Java HotSpot(TM) 64-Bit Server VM 
(24.51-b03-HJDK1000-20140529) for windows-amd64 JRE 
(1.7.0_51-b13-HJDK1000-20140529), built on May 29 2014 16:04:41 by "Java" 
with unknown MS VC++:1600
[JVM]Command : C:\Hitachi\APServer\jdk\bin\java.exe 
-Djava.class.path=. -XX:+HitachiVerboseGC HelloWorld