HPjmeter 4.2 User's Guide

4 Monitoring Applications ............................................................................................36
Controlling Data Collection and Display.............................................................................................36
Setting Data Collection Preferences......................................................................................................36
Managing Node Agents........................................................................................................................37
Managing Node Agents On HP-UX................................................................................................37
Running Node Agent as a Daemon...........................................................................................37
Verifying HP-UX Daemon is Running.......................................................................................37
Starting Node Agents Manually................................................................................................37
Stopping Node Agents...............................................................................................................38
Node Agent Access Restrictions......................................................................................................38
Running Multiple Node Agents......................................................................................................38
Saving Monitoring Metrics Information...............................................................................................38
Saving Data from the Console.........................................................................................................39
Naming Monitoring Data Files.............................................................................................................39
Diagnosing Errors When Monitoring Running Applications..............................................................39
Identifying Unexpected CPU Usage by Method.............................................................................39
Viewing the Application Load........................................................................................................40
Checking for Long Garbage Collection Pauses...............................................................................40
Checking for Application Paging Problems....................................................................................40
Identifying Excessive Calls to System.gc()......................................................................................41
Reviewing the Percentage of Time Spent in Garbage Collection....................................................41
Checking for Proper Heap Sizing....................................................................................................43
Confirming Java Memory Leaks......................................................................................................43
Determining the Severity of a Memory Leak..................................................................................43
Identifying Excessive Object Allocation..........................................................................................44
Identifying the Site of Excessive Object Allocation.........................................................................44
Identifying Abnormal Thread Termination....................................................................................44
Identifying Multiple Short-lived Threads.......................................................................................44
Identifying Excessive Lock Contention...........................................................................................45
Identifying Deadlocked Threads.....................................................................................................45
Identifying Excessive Thread Creation...........................................................................................45
Identifying Excessive Method Compilation....................................................................................46
Identifying Too Many Classes Loaded............................................................................................47
Using the JMX Viewer...........................................................................................................................47
Understanding the JMX Summary View.........................................................................................48
JMX Summary Tab.....................................................................................................................48
JMX Memory Tab.......................................................................................................................49
JMX Threads Tab........................................................................................................................51
JMX Runtime Tab.......................................................................................................................52
JMX Notifications Tab................................................................................................................52
Changing Mbean Values and Monitoring the Result......................................................................52
Using the Functions in the JMX Server View..................................................................................53
The MBean Filter........................................................................................................................53
The MBean Attribute Tab...........................................................................................................54
The MBean Operations Tab........................................................................................................55
The MBean Notifications Tab.....................................................................................................56
The MBean Information Tab......................................................................................................56
5 Profiling Applications .................................................................................................58
Profiling Overview................................................................................................................................58
Tracing.............................................................................................................................................59
Sampling..........................................................................................................................................59
Tuning Performance........................................................................................................................59
Preparing a Benchmark........................................................................................................................60
Collecting Profile Data..........................................................................................................................61
4 Table of Contents