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Running a Performance Analysis
Investigating Your Results
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Threads are excluded from the Call Graph by default, because the vast majority of
threads are created by the application server. You have no control over these threads, so
you can safely hide the data associated with them. What you do see are your
application’s methods. Your data set includes only the call trees initiated by the methods
that started your Java EE application.
In the Call Graph, you can include the threads in the data set. Including threads allows
you to analyze their call trees collectively and individually. For example, if you find an
expensive method invoked by two threads, you can select one thread and isolate its call
tree. The data changes to reflect only the single thread. If the method is still a hotspot,
the selected thread is probably the cause. To confirm your assumption, you can reset the
graph and select the other thread.
Regardless of the type of application you are analyzing, your results would be clearer in
the Call Graph if you used the data collection filters. Your own methods stand out if you
collected method-level detail on your own package, and left all other code in the
encapsulated state. Encapsulated data is displayed in the Call Graph as locked nodes,
(that is, there is a lock icon on the node) or nodes with an asterisk (Encapsulated using
the Grouped option).
To identify hotspots along the critical path:
1 In the Snapshots Navigator, double-click the Performance snapshot that you want
to analyze.
The Summary view opens, providing you with a list of potential hotspots and
suggesting the top five focus methods with which you can continue your
Performance analysis.
Note
When JDBC data is recorded in the snapshot, the Methods tab is displayed on the
foreground and the JDBC tab is displayed on the background.
2 In the Methods tab, select the Elapsed Time or the CPU Time option to display
the suggested methods based on elapsed time data or on CPU time data (provided
that the latter is available).
3 Select a method in the list, right-click, and select Investigate.
The Methods view opens.
4 Ensure that the Call Graph is set to sort methods by Elapsed Cumulative Time
and the Color to Show metric is set to Hot Paths (Elapsed Time).
5 If you are analyzing a Java EE application, you can focus your investigation by
isolating the tree that represents your application. Find the entry point to your
application (for example, a doGet() or doPut() method), select a method,
right-click, and select Isolate Selected Node.