Changed Statistics Views in the Profiler of IBM Rational Application Developer V6.0.1

Abstract

IBM Rational Application Developer V6 gives you the ability to profile Java applications. Profiling gives you insight into the performance characteristics of your application. Knowing more about your application's run-time behavior promotes a better understanding of its resource requirements and potential bottlenecks.

See chapter 15 of WebSphere Application Server V6 Scalability and Performance Handbook, SG24-6392-00 for detailed information on the Profiler itself, for information on how to prepare application servers for profiling, and to learn how to set up the profiling function in IBM Rational Application Developer V6.

Contents


IBM Rational Application Developer V6 gives you the ability to profile Java applications. Profiling gives you insight into the performance characteristics of your application. Knowing more about your application's run-time behavior promotes a better understanding of its resource requirements and potential bottlenecks.

Profiler views
In order to understand the behavior of an application, there are a number of different views that you can display in the Profiling Perspective.
Use the following steps to open a view:
  1. Right-click and select Monitoring.
  2. Select Collecting->Profiling (date) ->Open With. You have several options/views to choose from. The available views differ between the Java Profiler and the J2EE Profiler.

Statistics views in Rational Application Developer V6.0.1
There is a significant change in the way you access statistics views in the Profiler in Rational Application Developer V6.0 compared to V6.0.1. In V6.0 you could select Package statistics, Class statistics, Method statistics, and Instance statistics right from the context menu of the appropriate profiling agent. In V6.0.1 this was regrouped to three different kinds of views, each one with up to four different levels.

The three statistics views are:
  • Code Coverage Statistics
  • Execution Statistics
  • Memory Statistics

The four levels are:
  • Package Package icon
  • Class Class icon
  • Method (not available for Memory Statistics) Method icon
  • Instance (only available for Execution and Memory Statistics) Instance icon

You can switch between the package, class, method, and instance levels by selecting one of the toolbar controls.

Opening other views
While working in the statistics views, you can select to open the source code of a selected item, choose the columns to display, or export the data to a file in HTML format using the toolbar controls.

Filtering
You can use the filter function (first icon on the toolbar Filter function on toolbar) to filter out data.

Working with columns
There are different controls available that allow you to manipulate the columns displayed in a view. You can specify the columns to display in the view, show the change in each numeric column, and sort the column data.

To specify which columns to display in the view:
  1. Select the Choose Column button in the toolbar.
  2. In the Choose Columns dialog, select the columns that you want displayed in the view.
  3. Click OK to apply the changes.

To show the change in each numeric column since the last refresh, select Show Delta Columns in the toolbar.

To sort column data:
  1. Click the title of a column.
  2. Click the title of the column again to sort it in reverse order. The title of the column is prefixed with < if the column is sorted in ascending order. It is prefixed with > if it is sorted in descending order.

Memory Statistics
The Memory Statistics view displays statistics about the application heap. It provides detailed information about what is currently loaded into the JVM memory. For example, you can see the names of the classes currently loaded, the number of instances that are alive, and the memory size allocated by every class. Memory statistics are available at the package, class, and instance level.

You can display information such as Class, Package, Total Instances, Live Instances, Collected, Total Size (bytes), and Active Size (bytes) in the Memory Statistics views.
The data can also be shown as percentages. To display the data as percentages, select the Show as Percentage icon (Show as Percentage icon) in the toolbar.
You can access the other views from the Memory Statistics views:

To access Object references of a selected object:
  1. Right-click the object.
  2. select Show Object References. The Object References view is opened and populated with data for the selected object.

To access the Source code view of a selected object:
  1. Right-click the object.
  2. Select Open Source.

Access the Memory Statistics view via the Java Profiling Agent:
  1. Right-click and select Monitoring.
  2. Select Collecting->Open With -> Memory Statistics, or click the appropriate icon in the toolbar.
  3. Select the Package, Class, or Instance level icons to display the appropriate information.

Memory Statistics Table - Package level

Execution Statistics
The Execution Statistics view displays statistics about the application execution time. It provides data such as the number of methods called and the amount of time taken to execute every method. Execution statistics are available at the package, class, method, and instance level.

Information such as Method, Class, Package, Base Time (seconds), Inherited Base Time (seconds), Average Base Time (seconds), Cumulative Time (seconds), Inherited Cumulative Time (seconds), Calls, Inherited Calls and Cumulative CPU Time (seconds) can be displayed in the Execution Statistics views. The available selection depends on the level. For example, you cannot select Method when looking at the class level information.

The data can also be shown as percentages.

Following are other profiling views and source code views that can be opened from the Execution Statistics view:
  • Object references view.
  • The Method Invocation view. You need to switch to the Package, Class, or Method display mode. Select a method, right-click, and select Show Method Invocation.
  • Source code view.

Access the Execution Statistics via the J2EE Request Profiler:
  1. Right-click, and select Monitoring.
  2. Select Collecting -> Open With -> Execution Statistics. Select the Package, Class, or Instance level icons to display the appropriate information. You can use the filter function (first icon on the toolbar) to filter out data.

Execution Statistics view - Method level

Code Coverage Statistics

The Coverage Statistics view displays usage statistics for a selected type of object. Coverage statistics are available at the Package, Class, Method, and Instance levels.

Using this view, you can easily identify classes that are fully utilized and those that are underutilized, which in turn allows you to focus test efforts on those underutilized classes. The Code Coverage Statistics view also provides an overview of the classes and methods referenced for a particular task. This can be useful in identifying unexpected method calls.

The available information is Item names, Class, Package, Calls, Methods missed, Methods hit, % Methods Hit, Units Hit, Total Units and, % Units Hit.

You can only select to open the source code view. No other views can be accessed from the Coverage Statistics.

Access the Execution Statistics via the J2EE Request Profiler.
  1. Right-click, and select Monitoring.
  2. Select Collecting->Open With ->Coverage Statistics. Select the Package, Class, or Method level icons and the filter function to display the desired information.

Coverage Statistics view - Class level

Special Notices

This material has not been submitted to any formal IBM test and is published AS IS. It has not been the subject of rigorous review. IBM assumes no responsibility for its accuracy or completeness. The use of this information or the implementation of any of these techniques is a client responsibility and depends upon the client's ability to evaluate and integrate them into the client's operational environment.

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Publish Date
21 March 2006


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