7.1 Options and properties used in Java VM
This section describes an overview of all options and properties used in Java VM. This section also describes an overview of the environment variables used in Java VM.
Notes
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The default values of the Java VM options and properties described here might differ from the default values of the servers.
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For details on the default values of the servers, see the description Changing Java VM options by using the create-jvm-options subcommand in the User's Guide.
Java VM options used for list displays
Option |
Overview |
Details |
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Displaying a list of extended Java VM options |
Displays a list of extended Java VM options. |
Java VM options used for the extended thread dump functionality
Option |
Overview |
Details |
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Outputting extended thread dump information |
Specifies whether to output extended thread dump information. |
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Outputting extended thread dumps to the standard output |
Specifies whether to output extended thread dumps to the standard output. |
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Outputting the following information as the thread information of extended thread dumps: the number of times that thread processing was blocked and the number of times the thread was in the wait status |
Specifies whether to output the following information as the thread information of extended thread dumps: the number of times that thread processing was blocked and the number of times the thread was in the wait status. |
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Outputting the following information as the thread information of extended thread dumps: user CPU time and kernel CPU time |
Specifies whether to output the following information as the thread information of extended thread dumps: user CPU time and kernel CPU time. |
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Outputting hash codes as the thread information of extended thread dumps |
Specifies whether to output hash codes as the thread information of extended thread dumps. |
Java VM options used for Java VM log files
Option |
Overview |
Details |
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Specifying the prefix and the output-destination directory of Java VM log files |
Specifies the prefix and the output-destination directory of Java VM log files. |
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Specifying the maximum size for each Java VM log file |
Specifies the maximum size for a single log file. This specification prevents the size of log files from increasing. If the size of a file reaches the maximum size, no logs are output to the file. |
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Specifying how to output log information if an input or output error occurs during log file creation |
Specifies how to output log information if an input or output error occurs during log file creation. Note that Java VM continues processing regardless of the specified value. This option applies to Java VM log files and the log files for the explicit memory management functionality. |
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Specifying the maximum number of Java VM log files that are to be created |
Specifies the maximum number of Java VM log files that are to be created. This specification prevents the number of created files from increasing. |
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Enabling or disabling the asynchronous output functionality for log files |
Specifies whether to enable or disable the asynchronous output functionality for log files. |
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Outputting the header information when a Java VM log file is opened |
Specifies whether to output the header information when a Java VM log file is opened. The header information contains the following information: the Java VM version in the 1st line, and the startup command line information in the 2nd line. You must take into account the size of the output header information when specifying the maximum file size for the -XX:HitachiJavaLogFileSize option. This option applies to Java VM log files and the log files for the explicit memory management functionality. |
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Specifying the rotation time of the Java VM log file |
If the rotation type of the Java VM log file is the shift type, specify the time when the storage destination file is to be switched for this option. This option applies to Java VM log files and the log files for the explicit memory management functionality. The Java VM log file will be switched at the time specified in this option. |
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Specifying the rotation type of the Java VM log file |
Specifies the rotation type of the Java VM log file. This option applies to Java VM log files and the log files for the explicit memory management functionality. |
Java VM option used for the detailed time output
Option |
Overview |
Details |
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Outputting the time (accurate to the millisecond) to the Java VM log file |
Specifies whether to output the time accurate to the millisecond. This option applies to Java VM log files and the log files for the explicit memory management functionality. |
Java VM options used for the extended verbosegc functionality
Option |
Overview |
Details |
---|---|---|
Outputting the extended verbosegc information in CSV format |
Specifies whether to output the extended verbosegc information in CSV format. |
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Outputting the extended verbosegc information to the Java VM log file when a GC occurs |
Specifies whether to output the extended verbosegc information when a GC occurs. |
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Outputting the user CPU time and the kernel CPU time as the extended verbosegc information |
Specifies whether to output the CPU usage time as the extended verbosegc information. |
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Specifying the interval (in seconds) for outputting the extended verbosegc information |
Specifies the interval (in seconds) for outputting the extended verbosegc information. |
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Outputting details on the causes of GCs |
Specifies whether to output details on the causes of GCs. |
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Outputting the date and time when a GC started to the extended verbosegc information |
Specifies whether to output the date and time when a GC started to the extended verbosegc information. |
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Outputting the following information to the Java VM log file: the cumulative heap size allocated by Java VM when java.io.File.deleteOnExit() was called, and the number of times the method was called |
Specifies whether to output the following information to the Java VM log file: the cumulative heap size allocated by Java VM when java.io.File.deleteOnExit() was called, and the number of times the method was called. |
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Outputting the heap information that is internally managed by Java VM, to the Java VM log file |
Specifies whether to output the heap information that is internally managed by Java VM, to the Java VM log file. |
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Outputting the age distribution for the Survivor area to the Java VM log file |
Specifies whether to output the age distribution for the Survivor area to the Java VM log file when -XX:+PrintTenuringDistribution is specified. |
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Outputting the number of Java threads to the Java VM log file |
Specifies whether to output the number of Java threads to the Java VM log file. This information can be used to monitor the number of Java threads. |
Java VM options used for the functionality that outputs the code cache area information
Option |
Overview |
Details |
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Specifying the usage threshold rate of the code cache area |
Specifies the usage rate of the code cache area. This is the rate at which a message is output to indicate that usage has reached the threshold value. |
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Outputting a message to the Java VM log file when the code cache area becomes insufficient during JIT compilation of a Java method |
Specifies whether to output a message to the Java VM log file when the code cache area becomes insufficient during JIT compilation of a Java method. |
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Specifying whether to output the following information to the Java VM log file: the usage rate of the code cache area and the message informing the user that usage has reached the threshold value |
Specifies whether to output the usage rate of the code cache area. In addition, this option specifies whether to output the message informing the user that usage has reached the threshold value, to the Java VM log file. |
Java VM options used for the extended functionality when an OutOfMemoryError occurs
Option |
Overview |
Details |
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Enabling or disabling the functionality that forcibly terminates processing when an OutOfMemoryError occurs |
If an OutOfMemoryError occurs, a message is output to the standard output and processing is forcibly terminated. |
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Outputting thread dumps when an OutOfMemoryError occurs |
Thread dumps are output when an OutOfMemoryError occurs. When the C heap in the J2SE class library is insufficient, thread dumps are not output, to prevent the recurrence of C heap insufficiency due to the output of thread dumps. |
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7.8.3 -XX:[+|-]HitachiOutOfMemoryAbortThreadDumpWithJHeapProf |
Outputting class-wise statistics to the thread dump log file that is output when an OutOfMemoryError occurs |
Specify whether to output class-wise statistics to the output thread dump log file that is output when -XX:+HitachiOutOfMemoryAbortThreadDump is specified. If G1GC is used, this functionality is disabled. If the option that enables this functionality is specified when G1GC is being used, the specification is not applied, and this functionality is disabled. |
Outputting the cause type when an OutOfMemoryError occurs |
Specifies whether to output the cause type when an OutOfMemoryError occurs. |
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Outputting the memory size requested when an OutOfMemoryError occurs |
Outputs the memory size requested when an OutOfMemoryError occurs. |
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Outputting the exception information and the stack trace to the Java VM log file when an OutOfMemoryError occurs |
Specifies whether to output the exception information and the stack trace to the Java VM log file when an OutOfMemoryError occurs. |
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Specifying the number of characters (in bytes) per line of the stack trace that is output when an OutOfMemoryError occurs |
Specifies the number of characters (in bytes) per line of the stack trace that is output when an OutOfMemoryError occurs. |
Java VM options used for the class library trace functionality
Option |
Overview |
Details |
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Outputting the stack trace for the class library |
Outputs the stack trace for the API to the Java VM log file when a method that affects the entire system is used. |
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Specifying the number of characters (in bytes) per line of the stack trace for the class library |
Specifies the number of characters (in bytes) per line of the stack trace for the class library that is output when the -XX:+HitachiJavaClassLibTrace option is specified. |
Java VM options used for the functionality that outputs the local variable information
Option |
Overview |
Details |
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Outputting the character strings of the String objects that were obtained via a local variable object |
Outputs the character strings of the String objects that were obtained via a local variable object in a class corresponding to applicable_range, as strings that represent variable values. |
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Adding the local variable information of each method to the stack traces generated when thread dumps are output, and outputting the stack traces |
Adds the local variable information of each method to the stack traces that are generated when thread dumps are output, and then outputs the stack traces. |
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Outputting the local variable information of the methods in the stack traces |
Collects the local variable information of the methods in the stack traces when the java.lang.Throwable.fillInStackTrace method is executed. |
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Changing the output format of local variable information to the simple output format, where one variable is output per line |
Changes the output format of the local variable information to the simple output format, where one variable is output per line. |
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Outputting actual object type names to the local variable information |
Outputs the name of the object type that is set for a class or an array-type local variable when collecting local variable information. |
Java VM options used for the explicit memory management functionality
Option |
Overview |
Details |
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Specifying the upper limit on the release ratio that is set during the automatic release processing of the explicit memory management functionality |
Specify the maximum release rate that can be set in the automatic release processing of the explicit memory management functionality. The release rate is the ratio of the amount of the heap area that is actually released by automatic release processing, to the amount selected during the automatic release processing. |
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Specifying the file path for the explicit memory management functionality exclusion configuration file |
Specifies the file path for the explicit memory management functionality exclusion configuration file that is used by the functionality that excludes classes from the explicit memory management functionality. The explicit memory management functionality is not applied to the classes specified in this file. |
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Controlling (based on reference relationships) the movement of objects from the JavaHeap to Explicit memory blocks when full GC occurs |
Specifies whether to control (based on reference relationships) the movement of objects from the JavaHeap to Explicit memory blocks when full GC occurs. This option enables the objects that were moved to the Explicit heap when full GC occurred, to be moved to the Tenured area. |
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Specifying the file path for the configuration file that disables exclusions from the explicit memory management functionality |
Specifies the file path for the configuration file that disables exclusions from the explicit memory management functionality. This file is used by the functionality that excludes classes from the explicit memory management functionality. The functionality that excludes classes from the explicit memory management functionality is not applied to the classes specified in this file, even if those classes are also specified in the explicit memory management functionality exclusion configuration file. |
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Enabling or disabling the functionality that excludes classes from the explicit memory management functionality |
Specifies whether to enable or disable the functionality that excludes classes from the explicit memory management functionality. |
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Enabling or disabling the functionality for automatically placing Explicit memory blocks |
Specifies whether to enable or disable the functionality for automatically placing Explicit memory blocks. |
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Specifying the file path for the automatic placement configuration file used by the functionality for automatically placing Explicit memory blocks |
Specifies the file path for the automatic placement configuration file used by the functionality for automatically placing Explicit memory blocks. |
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Specifying the maximum size of the entire Explicit heap |
Specifies the maximum size of the entire Explicit heap. |
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Enabling or disabling the automatic release of the explicit memory management functionality |
Specifies whether to use the automatic release functionality of the explicit memory management functionality. |
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Enabling or disabling the functionality that saves the amount of memory in the Explicit heap that is used for HTTP sessions |
Specifies whether to enable or disable the functionality that saves the amount of memory in the Explicit heap that is used for HTTP sessions. |
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Specifying whether to allocate Explicit memory blocks by using the same method as 08-00 |
Specifies whether to allocate Explicit memory blocks by using the same method as 08-00. Enable this option if the applications that were used in 08-00 are to be used in 08-50, instead of the new functionality implemented in 08-50 and later. |
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Specifying the prefix and output-destination directory of the log file for the explicit memory management functionality |
Specifies the prefix and output-destination directory for the log files of the explicit memory management functionality. |
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Specifying the maximum size (in bytes) per log file of the explicit memory management functionality |
Specifies the maximum size (in bytes) per file. |
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Specifying the maximum number of log files that are to be created by the explicit memory management functionality |
Specifies the maximum number of Java VM log files that are to be created. This specification prevents the number of created files from increasing. |
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Specifying the event log level for the explicit memory management functionality |
Specifies the event log level for the explicit memory management functionality. |
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Changing the location where objects are moved during the release of Explicit memory blocks, to the Tenured area |
Specifies the location where objects are moved during the release of Explicit memory blocks. |
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Enabling or disabling the explicit memory management functionality |
Specifies whether to enable or disable the explicit memory management functionality. |
Java VM options used for specifying the maximum values for resources
Option |
Overview |
Details |
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Specifying the maximum memory size of the C heap to be allocated during JIT compilation |
Specifies the maximum memory size of the C heap to be allocated during JIT compilation. |
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Specifying the maximum number of threads |
Specifies the maximum number of threads. |
Java VM options used for the JIT compiler continuation functionality
Option |
Overview |
Details |
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Enabling or disabling the JIT compiler continuation functionality |
Specifies whether to enable or disable the JIT compiler continuation functionality. |
Java VM options used to execute Java application programs
Option |
Overview |
Details |
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Executing Java application programs |
If you execute the java command or the javaw command with this option specified, you will be able to execute Java application programs. |
Java VM options used for the functionality for the compressed object pointer
Option |
Overview |
Details |
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Enabling or disabling the compressed object pointer functionality |
Specifies whether to enable or disable the compressed object pointer functionality. |
Java VM properties used for the finalize-retention-cancellation functionality
Property |
Overview |
Details |
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Enabling or disabling the finalize-retention-cancellation functionality |
Specifies whether to enable or disable the finalize-retention-cancellation functionality. |
Java VM properties used for performance-based trace analysis
Property |
Overview |
Details |
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Enabling or disabling performance-based trace analysis |
Specifies whether to enable or disable performance-based trace analysis. |
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Specifying the specification format for the performance-based trace analysis configuration file |
Specifies whether to enable each of the following specification formats for the performance-based trace analysis configuration file. |
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Specifying the file path for the performance-based trace analysis configuration file |
Specifies the file path for the performance-based trace analysis configuration file. |
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Specifying the maximum number of target methods of the performance-based trace analysis |
Specifies the maximum number of target methods of the performance-based trace analysis. |
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Outputting to the trace information, the line number of the last executed statement of the method |
Specifies whether to output to the trace information, the line number of the last executed statement of the method when the method ends normally. |
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Specifying the trace output level for performance-based trace analysis |
Specifies the output level for the names of traced methods. The names are output in the specified level to the optional information (OPT) of the performance-based trace analysis information. |
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Outputting the names of exception or error classes to the trace information |
Specifies whether to output the names of exception or error classes to the operation information (OPR) of the trace information when a method ends abnormally. |
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Specifying how the name of an exception or error class is edited if the name exceeds 32 characters |
Specifies how the name of an exception or error class is to be modified if the name exceeds 32 characters. If the name of an exception or error class is 32 characters or less, all characters are output to the trace information regardless of the specification in this property. |
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Outputting logs when the class file specified in the performance-based trace analysis configuration file is successfully overwritten |
Specifies whether to output logs when the class file specified in the performance-based trace analysis configuration file is successfully overwritten. |
Java HotSpot VM options used for Application Server
Option |
Overview |
Details |
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Continuing Java VM execution when a user logs off from Windows |
Specifies whether to continue Java VM execution when a user logs off from Windows in an environment that includes JDK version 6 or later. |
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Loading the native agent library |
Loads the native agent library libname. |
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Specifying the maximum size of the Compressed Class Space |
Specifies the maximum size of the Compressed Class Space. |
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Specifying the number of threads that can execute concurrent marking in parallel |
Specifies the number of threads that can execute processing for Concurrent Marking in parallel when G1GC is enabled. |
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Specifying the target amount of time for which applications are stopped by GC for G1GC |
Specifies the target amount of time (in milliseconds) for which applications are stopped by GC for G1GC. |
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Specifying the maximum value of the Metaspace area |
Specifies the maximum value of the Metaspace area. |
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Specifying the threshold value for the number of times Java objects are replaced in the From space and in the To space when CopyGC is executed |
Specifies the threshold for the number of times Java objects are replaced in the From space and in the To space when CopyGC is executed. After the specified threshold is exceeded, the Java objects to be replaced are moved to the Tenured area. |
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Specifying the standard value for the full GC that originated in the Metaspace area |
Specifies the standard value for the full GC that originated in the Metaspace area. |
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Specifying the ratio of the Tenured area to the New area |
Specifies the ratio of the Tenured area to the New area. |
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Specifying the number of threads that can execute G1GC in parallel |
Specifies the number of threads that can execute G1GC in parallel. |
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Specifying the maximum size of the code cache area |
Specifies the maximum size of the code cache area. |
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Specifying the ratio of the Eden area to each of the following spaces in the Survivor area: the From space and the To space |
Specifies the ratio of the New::Eden area to each of the following spaces in the New::Survivor area: the From space and the To space. |
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Specifying the target proportion of the Java objects in the Survivor area after GC is executed |
Specifies the target proportion (0% to 100%) of the New::Survivor area that is to be made up of Java objects after GC is executed. |
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Executing G1GC |
Specifies whether to execute G1GC. This option cannot be specified at the same time as the options (UseSerialGC and HitachiUseExplicitMemory). |
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Executing SerialGC |
Specifies whether to execute SerialGC. |
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Outputting the information specified in information_type |
Outputs the information specified in information_type. |
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Outputting logs to file whenever a GC event occurs |
Similar to -verbose:gc, a report is sent whenever a GC event occurs. In addition, data about the event is recorded in file. In addition to the information reported when -verbose:gc is specified, the amount of time (in seconds) that has elapsed from the first GC event is included at the beginning of each event report. |
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Specifying the initial size of the JavaHeap |
Specifies the initial size of the JavaHeap. |
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Specifying the maximum size of the JavaHeap |
Specifies the maximum size of the JavaHeap. |
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Generating the profile for a running program, and outputting the profiling data to the standard output |
If you specify this option, the profile for a running program is generated, and the profiling data is output to the standard output. This option is provided as a program development utility. This option is not intended for use in a system that is running in the production environment. |
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Specifying the maximum area size per stack |
Specifies the maximum area size per stack. |
Environment variables used in Java VM
Environment variables |
Overview |
Details |
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An environment variable that enables the java command to be executed |
If you execute the java command with this option specified, you will be able to execute Java application programs that do not link with Application Server. |
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Specifying the directory where thread dump files are output |
Specifies the directory where thread dump files are output in the batch file. |
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An environment variable that enables the javaw command to be executed |
If you execute the javaw command with this option specified, you will be able to execute Java application programs that do not link with Application Server. |