HPjmeter 4.3 User's Guide

Setting Data Collection Preferences...........................................................................................46
Managing Node Agents.........................................................................................................47
Managing Node Agents On HP-UX......................................................................................47
Running Node Agent as a Daemon.................................................................................47
Verifying HP-UX Daemon is Running................................................................................47
Starting Node Agents Manually......................................................................................47
Stopping Node Agents..................................................................................................48
Node Agent Access Restrictions...........................................................................................48
Running Multiple Node Agents............................................................................................48
Saving Monitoring Metrics Information......................................................................................48
Saving Data from the Console.............................................................................................49
Naming Monitoring Data Files.................................................................................................49
Diagnosing Errors When Monitoring Running Applications..........................................................49
Identifying Unexpected CPU Usage by Method......................................................................49
Viewing the Application Load..............................................................................................50
Checking for Long Garbage Collection Pauses.......................................................................50
Checking for Application Paging Problems............................................................................50
Identifying Excessive Calls to System.gc()..............................................................................51
Reviewing the Percentage of Time Spent in Garbage Collection...............................................51
Checking for Proper Heap Sizing.........................................................................................53
Confirming Java Memory Leaks...........................................................................................53
Determining the Severity of a Memory Leak...........................................................................53
Identifying Excessive Object Allocation.................................................................................54
Identifying the Site of Excessive Object Allocation..................................................................54
Identifying Abnormal Thread Termination..............................................................................54
Identifying Multiple Short-lived Threads.................................................................................55
Identifying Excessive Lock Contention....................................................................................55
Identifying Deadlocked Threads...........................................................................................55
Identifying Excessive Thread Creation...................................................................................56
Identifying Excessive Method Compilation.............................................................................56
Identifying Too Many Classes Loaded...................................................................................57
Using the JMX Viewer.............................................................................................................57
Understanding the JMX Summary View.................................................................................58
JMX Summary Tab........................................................................................................58
JMX Memory Tab..........................................................................................................59
JMX Threads Tab...........................................................................................................61
JMX Runtime Tab...........................................................................................................63
JMX Notifications Tab....................................................................................................63
Changing Mbean Values and Monitoring the Result...............................................................63
Using the Functions in the JMX Server View...........................................................................64
The MBean Filter...........................................................................................................64
The MBean Attribute Tab................................................................................................64
The MBean Operations Tab............................................................................................66
The MBean Notifications Tab..........................................................................................67
The MBean Information Tab............................................................................................67
5 Profiling Applications ...............................................................................69
Profiling Overview..................................................................................................................69
Tracing.............................................................................................................................70
Sampling..........................................................................................................................70
Tuning Performance............................................................................................................70
Preparing a Benchmark...........................................................................................................71
Collecting Profile Data.............................................................................................................72
Profiling with -Xeprof..........................................................................................................72
Profiling with Zero Preparation.............................................................................................74
Contents 13