8.11 List of JavaVM options

This section discusses Hitachi JavaVM options. You can specify Hitachi JavaVM options in the following files:

The table below lists and describes the JavaVM options. In this table, the default value is the value that is assumed when the corresponding JavaVM option is omitted from the JavaVM options file for SDP servers (jvm_options.cfg) or the JavaVM options file for RMI connections (jvm_client_options.cfg).

Table 8-9 List of JavaVM options

No.ClassificationOption nameDescription
1Options for specifying the size and ratio of JavaVM memory space-Xmssize#1Specifies the initial Java heap size.
-Xmxsize#1Specifies the maximum Java heap size.
-XX:NewRatio=valueSpecifies the ratio of the Tenured area to the DefNew area. If value is 2, the ratio of the Tenured area to the DefNew area is 1:2.
-XX:PermSize=size#1Specifies the initial size of the Permanent area.
-XX:MaxPermSize=size#1Specifies the maximum size of the Permanent area.
2Extended thread dump function option-XX:[+|-]HitachiThreadDumpToStdoutSpecifies whether a thread dump is to be output to the standard output:
  • -XX:+HitachiThreadDumpToStdout: Outputs an extended thread dump to the standard output and Hitachi JavaVM log file.
  • -XX:-HitachiThreadDumpToStdout: Outputs an extended thread dump only to the Hitachi JavaVM log file, not to the standard output.
The default value is -XX:+HitachiThreadDumpToStdout.
3Hitachi JavaVM log file options-XX:HitachiJavaLog:character-stringSpecifies a prefix for the log file name. A log file name is created in the format character-stringxx.log (xx: serial number, 01 to 99).
For example, if you specify Samp for character-string, the log file name would be Samp01.log.
For character-string, you can also specify a path. If you specify a directory for character-string, a log file is created with the default name in the specified directory.
The default value is javalog.
-XX:HitachiJavaLogFileSize=integer-valueSpecifies the maximum size of one file (in kilobytes), as an integer from 1024 to the value of INT_MAX. If the specified value exceeds the maximum size, nothing will be output to that file.
The default value is 256.
If the specified value is not within the permitted value range, 1024 is assumed.
-XX:HitachiJavaLogNumberOfFile=integer-valueSpecifies the maximum number of files that can be created (in order to limit the number of log files), as an integer from 1 to 99. When the maximum number of files is reached, data is output again to the first file that was created.
The default value is 4.
If a value greater than 99 is specified, 99 is assumed. If 0 or a smaller value is specified, 1 is assumed.
4Detailed time output option-XX:[+|-]HitachiOutputMilliTimeSpecifies whether the time is to be output in milliseconds:
  • -XX:+HitachiOutputMilliTime: Outputs the time to the Hitachi JavaVM log file in milliseconds.
  • -XX:-HitachiOutputMilliTime: Outputs the time to the Hitachi JavaVM log file in seconds.
The default value is -XX:-HitachiOutputMilliTime.
5Extended verbosegc function option-XX:[+|-]HitachiVerboseGC#2Specifies whether the extended verbosegc information is to be output when a garbage collection occurs:
  • -XX:+HitachiVerboseGC: Outputs the extended verbosegc information to the Hitachi JavaVM log file when a garbage collection occurs.
    The extended verbosegc information includes information about the Eden, Survivor, Tenured, and Perm types, which are internal areas for garbage collection.
  • -XX:-HitachiVerboseGC: Does not output the extended verbosegc information to the Hitachi JavaVM log file when a garbage collection occurs.
The default value is -XX:-HitachiVerboseGC.
-XX:[+|-]HitachiVerboseGCPrintCause#3Specifies whether the cause of garbage collection is to be output.
  • -XX:+HitachiVerboseGCPrintCause: Outputs the cause of garbage collection at the end of the extended verbosegc information.
  • -XX:-HitachiVerboseGCPrintCause: Outputs the extended verbosegc information in the regular format.
The default value is -XX:+HitachiVerboseGCPrintCause.
6Extended function option in the event of OutOfMemoryError-XX:[+|-]HitachiOutOfMemoryStackTrace#2Specifies whether a stack trace is to be output in the event of OutOfMemoryError.
  • -XX:+HitachiOutOfMemoryStackTrace: Outputs the exception information and stack trace to the Hitachi JavaVM log file in the event of OutOfMemoryError. For the stack trace, each stack is placed in buffer and then output after code conversion. Because a stack trace is output each time OutOfMemoryError is thrown, it might be output more than once when OutOfMemoryError is thrown again. Note that if OutOfMemoryError occurs during thread creation, stack trace is not output.
  • -XX:-HitachiOutOfMemoryStackTrace: Does not output a stack trace to the Hitachi JavaVM log file in the event of OutOfMemoryError.
The default value is -XX:-HitachiOutOfMemoryStackTrace.
7Class library trace function options-XX:[+|-]HitachiJavaClassLibTrace#2Specifies whether a stack trace is to be output for the class library.
  • -XX:+HitachiJavaClassLibTrace: Outputs a stack trace of the class library.
  • -XX:-HitachiJavaClassLibTrace: Does not output a stack trace of the class library.
The default value is -XX:-HitachiJavaClassLibTrace.
-XX:HitachiJavaClassLibTraceLineSize=integer-valueSpecifies the number of characters (in bytes) per line of class library stack trace, as an integer from 1024 to the value of INT_MAX. If there are more characters than specified, the leading part of the character string that follows at is deleted and as many characters as are specified are output.
The default value is 1024.
If the specified value is not within the permitted value range, 1024 is assumed.
8Local variable information output function options-XX:[+|-]HitachiLocalsInStackTraceSpecifies whether the local variable information is to be output to the stack trace during a thread dump output.
  • -XX:+HitachiLocalsInStackTrace: Outputs the local variable information to a stack trace when a thread dump is output.
  • -XX:-HitachiLocalsInStackTrace: Does not output the local variable information to a stack trace when a thread dump is output.
The default value is -XX:-HitachiLocalsInStackTrace.
-XX:[+|-]HitachiLocalsSimpleFormatSpecifies whether the simple format is to be used to output local variable information.
  • -XX:+HitachiLocalsSimpleFormat: Outputs the local variable information in the simple format.
  • -XX:-HitachiLocalsSimpleFormat: Outputs the local variable information in the regular format.
The default value is -XX:-HitachiLocalsSimpleFormat.
-XX:[+|-]HitachiTrueTypeInLocalsSpecifies whether the actual type name of a local variable object is to be output as a character string when the local variable information is output.
  • -XX:+HitachiTrueTypeInLocals: Outputs the actual object type name to the local variable information.
  • -XX:-HitachiTrueTypeInLocals: Does not output the actual object type name to the local variable information.
The default value is -XX:-HitachiTrueTypeInLocals.
#1
Units for size are bytes.
You can specify the value in kilobytes by adding k or K, or in megabytes by adding m or M.
Example:
-Xms6291456: 6,291,456 bytes
-Xms6144k: 6,144 kilobytes
-Xms6m: 6 megabytes
#2
If you specify these options, a Hitachi JavaVM log file is output.
#3
When the -XX:+HitachiVerboseGC option is specified, this option must also be specified.