Using the Class Loading Page

The Class Loading page contains information about classes loaded and unloaded during the recording.

This page displays class loading data in both tables and graphs.

Using the Class Loading Page: Selections and Aspects

Use the drop-down menus at the top of the page to choose a selection and aspect if desired. Data from other pages can be saved to the selection drop-down menu by dragging an area of a chart (or selecting data from a table) and choosing Store Selection or Store Selection and Set As Focused Selection from the context menu.

The following controls provide additional behavior:

Show concurrent: Show all events concurrent to the selected aspect.
Contained: Only show events that are fully contained in the time range from the active selection aspect
Same threads: Only show events in threads related to the active selection aspect.

Using the Class Loading Page: Tables and Graphs

You can select any of the following to be displayed on the graph:

Class Loading: The number of classes loaded during the interval.
Class Unloading: The number of classes unloaded during the interval.
Loaded Class Count: The number of classes loaded since JVM start.
Unloaded Class Count: The number of classes unloaded since JVM start.

The first table contains the Class Loaders and Class Statistics subtabs.

Table Columns are labeled as follows:

Class Loaders Tab

Defining Class Loader: The defining class loader.
Classes Loaded: The number of classes loaded by this class loader.
Classes Unloaded: The number of classes unloaded.

Class Loader Statistics Tab

Start Time: The defining class loader.
Classes Loaded: The number of classes loaded by this class loader.
Classes Unloaded: The number of classes unloaded.

This page also contains Class Loading, Class Defining and Class Unloading subtabs.

Class Loading Tab

Loaded Class: The name of the loaded class.
Duration: The duration of the class loading.
Defining Class Loader: The name of the defining class loader.
Initiating Class Loader: The name of the initiating class loader.
Thread: The thread where the class was loaded.
End Time: The end time of the class loading event.

Class Defining Tab

Start Time: The time at which the class was defined.
Defining Class Loader: The name of the defining class loader.
Defined: The name of the class that was defined

Class Unloading Tab

Unloaded Class: The name of the unloaded class.
Defining Class Loader: The name of the defining class loader.
End Time: The end time of the class unloading event.

Using the Class Loading Page: Configuring Rules

You can set configuration attributes for the rules associated with this page by clicking the Edit Configuration icon.

The following options are available:

Class Leak

Warning limit: The number of loads to a class that should trigger a warning.
Class limit: the maximum number of classes exceeding the Warning Limit to report.

Class Loading Pressure

Classloading duration limit: The shortest classloading duration that should trigger a warning.
Classloading ratio limit: The minimum ratio between time spent in classloading and the total duration of the recording.