HP jmeter Software for -UX guide

Figure 6-2 Summary Panel Showing Garbage Collection Statistics

Heap Capacity Initial, final, and peak sizes allocated for various organizational spaces in the heap.

Peak Usage of Capacity The highest percentage of actual use by the application of the heap at its final capacity configuration. A rule of thumb for optimal utilization would be to have the eden space at 100% with the survivor and old spaces showing some reserve capacity, depending on the application.

GC Activity Summary In this example, a comparison of scavenges and full garbage collection of the old and permanent generations, showing number of GC occurrences, duration, and memory usage for each GC type displayed.

Duration of the Measurement The approximate, elapsed, wall clock time for the entire data collection.

Measurement Enabled and Measurement Disabled “Measurement enabled” refers to the total time during which zero preparation GC data collection has been activated during the session thus far. “Measurement disabled” refers to the total time during which no data was collected (zero preparation GC data collection is not in use). These values are visible on this tab when zero

Basic Garbage Collection Concepts

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HP jmeter Software for -UX manual Summary Panel Showing Garbage Collection Statistics

Contents

HPjmeter 4.2 Users Guide Document Notice Table of Contents Monitoring Applications Analyzing Garbage Collection Data 116 Unfinalized Objects Live Objects Bytes 192 187197 199 Intended Audience About This DocumentTypographic Conventions Additional HPjmeter Documents Related Information HP Encourages Your Comments Publishing History Introducing HPjmeter Features Node Agent ConceptsJVM Agent Platform Support and System Requirements Completing Installation of HPjmeterAgent Requirements Console Requirements File Locations Completing the installationAttaching to the JVM Agent of a Running Application Preparing to run Java On Java Example Usage Selecting Other JVM Agent Options JVM Agent OptionsShowing Version Information Include=filter1filter2..., exclude=filter1filter2 To specify a file name Noalloc Working with Firewalls Security AwarenessJVM Options Usage Examples Configuring User Access Getting Started Using HPjmeter to Monitor Applications To connect to a node agent via a SecureShell SSH tunnel Using HPjmeter to Monitor Applications Set Session Preferences When the Optional Port Box Is Not Used Getting Started View Monitoring Metrics During Your Open Session Using HPjmeter to Analyze Profiling DataChanging Session Preferences During a Session Configure your application Using HPjmeter to Analyze Garbage Collection Data Monitoring Demonstration Instructions Memory Leak Applications See also Heap Usage Notification Thread Deadlock Sample Thread Deadlock Example Display Controlling Data Collection and Display Setting Data Collection PreferencesMonitoring Applications Managing Node Agents On HP-UX Managing Node AgentsRunning Node Agent as a Daemon Verifying HP-UX Daemon is Running Saving Monitoring Metrics Information Node Agent Access RestrictionsRunning Multiple Node Agents Stopping Node Agents Naming Monitoring Data Files Diagnosing Errors When Monitoring Running ApplicationsSaving Data from the Console Identifying Unexpected CPU Usage by Method Checking for Long Garbage Collection Pauses Checking for Application Paging ProblemsViewing the Application Load Reviewing the Percentage of Time Spent in Garbage Collection Identifying Excessive Calls to System.gc Monitoring Applications Determining the Severity of a Memory Leak Checking for Proper Heap SizingConfirming Java Memory Leaks Identifying the Site of Excessive Object Allocation Identifying Excessive Object AllocationIdentifying Abnormal Thread Termination Identifying Multiple Short-lived Threads Identifying Excessive Thread Creation Identifying Excessive Lock ContentionIdentifying Deadlocked Threads Example Metric Method Compilation Count Identifying Excessive Method Compilation Identifying Too Many Classes Loaded Using the JMX Viewer JMX Summary Tab Understanding the JMX Summary View JMX Memory Tab Appearance of the Summary JMX Viewer When First Opened JMX Viewer with Summary Memory Tab Selected JMX Viewer with Summary Threads Tab Open JMX Threads Tab JMX Notifications Tab Changing Mbean Values and Monitoring the ResultJMX Runtime Tab MBean Filter Using the Functions in the JMX Server View MBean Attribute Tab 10 MBean Operations Tab Open for Display MBean Operations Tab MBean Information Tab MBean Notifications Tab 12 MBean Information Tab Open for Display Profiling Overview Profiling Applications Sampling Tuning PerformanceTracing Preparing a Benchmark Profiling with -Xeprof Collecting Profile Data Profiling with Zero Preparation If timeon=sig... has not been specified, the default is Following options are useful Profiling with -agentlibhprof Supported -agentlibhprofoptions Generate more complete call graphs Naming Profile Data Files Inclusive Method CPU Times Profiling with -Xeprof Profiling with -agentlibhprof Considerations in Interpreting the Data Approaches to Analyzing Performance DataLooking at the Data from the Bottom Up Looking at the Data from the Top Down Inclusive Versus Exclusive Time Locating Summary Information for Saved Data SetsTime Units CPU Versus Clock Time Estimate menus Adjusting Scope Comparing Profiling Data Files Scaling Comparison Data Key to Thread States Reported by Reading Profiling Histograms Interpreting the Histogram Presentation Interpreting Call Graph Data Using Call Graph Trees Example of Node Color Display Options for Manipulating the Call Tree Display Using Sub-TreesTree Pruning Auto-Expanding the Call Tree Searching the Trees Using Heuristics to Locate Possible Hot Spots Using Heuristics to Locate Possible Hot Spots Data Collection with -Xverbosegc Analyzing Garbage Collection DataObtaining Garbage Collection Data Java ... -Xverbosegchelp 13, Old generation, in bytes. These spaces are reported Collecting Glance Data for Viewing in HPjmeter Collecting GC Data with Zero Preparation Related Topics Data Collection with -Xloggc Naming GC Data Files Using -XX+PrintGCDetails and -XX+PrintHeapAtGC Together Comparing Garbage Collection Data Files Key to Garbage Collection Types Recognized by HPjmeter Basic Garbage Collection Concepts Common Garbage Collection Types Recognized by HPjmeter Understanding the Summary Presentation of GC Data Summary Panel Showing Garbage Collection Statistics Understanding the System Details Captured with GC Data Basic Garbage Collection Concepts Analyzing Garbage Collection Data Starting the Console Using the ConsoleUsing the Main Window Functions Main Console Window Data Representation JVM Agent Icons and Their MeaningNode Agent Saving Data Open and Cached SessionsTime Slice Entries Console Menu Choices Console Tool Bar Buttons Remember Main Window Location Monitor Menu Console Guide Location and First Screen Console Guide Specifying Metrics to Collect for Monitoring Setting Monitoring Session PreferencesStatus Bar Enabling Monitoring Alerts Adding Filters Specifying Filters for MonitoringEditing Filters Specifying Filter Sets Using AlertsViewing Monitoring Data in HPjmeter Appearance of Alert Threshold in GC Duration Visualizer Appearance of Alert Notices in the Main Console Pane Using the Alert Controller Alert Controller Window Viewing a Log of the Alert History Editing E-mail Notification Attributes Abnormal Thread Termination Alert Responding to Alerts Identifying Abnormal Thread Termination Thread Histogram GC Duration Notification Expected Out Of Memory Error AlertExcessive Compilation Alert Java Collection Leak Locations Alert Heap Usage Notification 13 Java Collection Leak Locations Visualizer Array Leak Locations Alert 14 Array Leak Locations Visualizer Process CPU Usage Alert System CPU Usage Alert Unfinalized Queue Growth Thread Deadlock Alert Profiling Data Viewer Using Visualizer Functions Locating Information About a JVM and its Environment Using Monitoring Displays Java Method HotSpots Monitor Code and/or CPU Activity Menu Details Thrown Exceptions with Stack Traces Thrown Exceptions Monitoring Metric Thrown Exceptions with Stack Traces Heap Monitor Monitor Memory and/or Heap Activity Menu Monitoring Metric Garbage Collections Garbage Collections GC Duration Percentage of Time Spent in Garbage Collection Unfinalized Objects Allocated Object Statistics by Class Allocating Method Statistics Current Live Heap Objects Name of class to which object belongs Thread Histogram Monitor Threads and/or Locks Menu Already acquired by another thread 14 Monitoring Metric Lock Contention Lock Contention Method Compilation Count Monitor JVM and/or System Activity Menu Loaded Classes Method Compilation Frequency 17 Monitoring Metric Loaded Classes Related Topics Percent % CPU Utilization Viewing Profiling or GC Data in HPjmeter Using Profile Displays Using Visualizer Functions Inline Candidates Exceptions Thrown Memory Leaks Method Call Count Menu ChoicesProfile Code and/or CPU Activity Call Graph Tree with Call Count Exclusive Method Times CPUExclusive Method Clock Times Call Graph Tree with Clock Time Call Graph Tree with CPUInclusive Method CPU Times Inclusive Method Clock Times Average Inclusive Method CPU Times Average Exclusive Method Clock TimesAverage Inclusive Method Clock Times Starvation by Method Starvation Ratio Profile Memory and/or Heap ActivityMethods with Loops Exclusive Class CPU Times Created Objects Count Objects Created by MethodCreated Objects Bytes Live Objects Count Reference Sub-Trees by Size Reference Graph Tree Using Profile Displays For string and char arrays, see String and char arrays 21 Long String Pop-up Box 23 Class Loaders Visualizer Class Loaders 24 Class Types Pop-up Window Guidelines Residual Objects Count Profile by ThreadsResidual Objects Bytes Threads Histogram Thread Groups Histogram Profile by Locks Lock Delay Call Graph Tree Lock Delay Method ExclusiveContested Lock Claims by Method All Lock Claims by Method Lock Contention Ratio by Method Lock Delay Method InclusiveAverage Exclusive Method Lock Delay Exclusive Method Lock Delay / Clock Time Exclusive Class Lock Delay Using Heuristic Metrics from the Estimate MenuInline Candidates Exceptions Thrown Heap Usage After GC Using Specialized Garbage Collection Displays 27 GC Metric Heap Usage After GC Related Topics Duration Stop the World 28 GC Metric Duration Related Topics Cumulative Allocation 29 GC Metric Cumulative Allocation Related Topics Creation Rate 30 GC Metric Creation Rate Related Topics Allocation Site Statistics 31 GC Metric Combined Sets of Allocation Site Statistics 32 GC Metric Separated Sets of Allocation Site Statistics Using Visualizer Functions Filter Field Descriptions Using Visualizer Functions User-Defined X-Y Axes 37 User-Defined Comparisons of GC Metrics Related Topics Multiple User-Defined 38 Multiple User-Defined Metrics Glance Data 40 GC Metric Glance Data 41 Glance Data Metric Configuration Box Run Queue Average Are private Glance System Call Data 42 GC Metric Glance System Call Data Common Tool Bar Buttons Using Visualizer Tool Bars Tool Bar Buttons for Manipulating Garbage Collection Data Tool Bar Buttons for Manipulating Tabular DataTool Bar Buttons for Manipulating Graphical Data Mark an Item for Search Special Button or Other Gadget Functions Find a Search Pattern 44 Locating an Item Changing Time Interval in GC Data Visualizers Pause or Resume Graphical Time-based Scrolling 46 The View Menu Selections in the GC Viewer Using Visualizer Tool Bars Changing Time Interval in Monitoring Visualizers 50 Time Interval Use in a Monitoring Visualizer Change Color Selection for Histogram Display Thread Histogram Profile by Threads Performance Overhead on Running Applications Understanding How HPjmeter Works Console Overhead Using Confidence Interval to Indicate Sample ValidityData Sampling Considerations How Memory Leak Detection Works Related Topics Page Installation TroubleshootingDocumentation and Support Identifying Version Numbers See also To Take Advantage of Dynamic Attach Console JVM agent If you see this JVM agent error on startup Zero Preparation Profiling Node agent Unexpected Behavior in Visualizers Quick References Connecting to the HPjmeter Node Agent Start and stop verbose GC data 0.14 0.02 Glossary Active mode Jvmpi SSL Index Symbols Alert Notification Editor, 107 alerts Restore Roots Alert Notification Editor, 108 count Collecting with zero preparation, 83 GC event Glance system call data, 174 graphical scrolling JVM Duration Stop the World, 158 enable, 99 User-Defined X-Y Axes for GC analysis, 167 viewing, 29 Program termination, 47 overhead Scale Special, 72 scaling data Xeprofoptions Xbootclasspath