You can output the size of all instances those are under the members of each class that has instances, to the extended thread dump, as the statistical information for each class. This statistical information is called as class-wise statistical information. You can output the class-wise statistical information multiple times for investigating the change in the Java object by garbage collection, the status of the Java object having short life, change in the size of each class, and the Java object parent-child relation. You can use this information for measuring the memory used for one transaction and for investigating the memory leak.

The class-wise statistical information is output based on the following functionality:

• Instance statistical functionality
• STATIC member statistical functionality
• Reference-related information output functionality
• Pre-statistical garbage collection selection functionality
• Unused objects statistical functionality in the Tenured area
• Base object list output functionality for Tenured augmentation factors

For details about each functionality, see 9.3.2 Functionality that requires the class-wise statistical functionality.

Moreover, in the class-wise statistical information, the instances in the Java heap (combining the Eden area, the Survivor area, and the Tenured area) and in the Permanent area are the target for statistics. Additionally, when using Explicit management heap functionality, you can also target the instances that exists the in Explicit heap for statistics. For details about how to output a class-wise statistical information, see 9.3.3 Outputting Statistic Information for Each Class.

Reference note

The extended thread dump is set such as to be output by default. For details about the settings for acquiring the extended thread dump, see 3.3.19(1) Settings for Acquiring Thread Dumps of JavaVM. For details about an output information, see 5.5 JavaVM Thread Dump.

Also, you can output the class-wise statistical information in the CSV format. For details about how to output the class-wise statistical information in the CSV format, see 9.10 Class-wise statistical information analysis functionality.