Data Collection with -Xloggc | HP jmeter Software for -UX guide

Let the collection generated by the JVM continue for the length of time that you think will be meaningful.

4.Stop the data collection interval by sending the same signal to the JVM: kill -PROF pid

You can now open the saved file in the HPjmeter console and view the collected metrics.

Time periods where no data is collected are shown in a light purple in all the GC graphic visualizers.

Figure 6-1 Appearance of GC Data Collected in Intervals During a Session

NOTE: For the signal to be captured by the JVM, you must either be logged in as root, or you must be the user who started the JVM.

Related Topics

•Using Specialized Garbage Collection Displays (page 157)

Data Collection with -Xloggc

-Xloggcdirects a smaller set of data to a file than what is available with -Xverbosegc. For every garbage collection, the following six fields are printed to the log file:

•Cumulative time since data collection began (in seconds)

•Garbage collection type

•Heap in use before the GC event

84 Analyzing Garbage Collection Data

Image 84

HP jmeter Software for -UX manual Data Collection with -Xloggc, Related Topics

Contents

HPjmeter 4.2 Users Guide Document Notice Table of Contents Monitoring Applications Analyzing Garbage Collection Data 116 Unfinalized Objects Live Objects Bytes 187 192197 199 About This Document Intended AudienceTypographic Conventions Additional HPjmeter Documents Related Information Publishing History HP Encourages Your Comments Features Introducing HPjmeter Concepts JVM AgentNode Agent Completing Installation of HPjmeter Platform Support and System RequirementsAgent Requirements Console Requirements Completing the installation File LocationsAttaching to the JVM Agent of a Running Application Preparing to run Java Example Usage On Java JVM Agent Options Showing Version InformationSelecting Other JVM Agent Options Include=filter1filter2..., exclude=filter1filter2 To specify a file name Noalloc Security Awareness JVM Options Usage ExamplesWorking with Firewalls Configuring User Access Using HPjmeter to Monitor Applications Getting Started 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 Using HPjmeter to Analyze Profiling Data Changing Session Preferences During a SessionView Monitoring Metrics During Your Open Session Configure your application Using HPjmeter to Analyze Garbage Collection Data Monitoring Demonstration Instructions Memory Leak Applications Thread Deadlock Sample See also Heap Usage Notification Thread Deadlock Example Display Setting Data Collection Preferences Monitoring ApplicationsControlling Data Collection and Display Managing Node Agents Managing Node Agents On HP-UXRunning Node Agent as a Daemon Verifying HP-UX Daemon is Running Node Agent Access Restrictions Saving Monitoring Metrics InformationRunning Multiple Node Agents Stopping Node Agents Diagnosing Errors When Monitoring Running Applications Naming Monitoring Data FilesSaving Data from the Console Identifying Unexpected CPU Usage by Method Checking for Application Paging Problems Viewing the Application LoadChecking for Long Garbage Collection Pauses Identifying Excessive Calls to System.gc Reviewing the Percentage of Time Spent in Garbage Collection Monitoring Applications Checking for Proper Heap Sizing Confirming Java Memory LeaksDetermining the Severity of a Memory Leak Identifying Excessive Object Allocation Identifying the Site of Excessive Object AllocationIdentifying Abnormal Thread Termination Identifying Multiple Short-lived Threads Identifying Excessive Lock Contention Identifying Deadlocked ThreadsIdentifying Excessive Thread Creation Identifying Excessive Method Compilation Example Metric Method Compilation Count Using the JMX Viewer Identifying Too Many Classes Loaded Understanding the JMX Summary View JMX Summary Tab Appearance of the Summary JMX Viewer When First Opened JMX Memory Tab JMX Viewer with Summary Memory Tab Selected JMX Threads Tab JMX Viewer with Summary Threads Tab Open Changing Mbean Values and Monitoring the Result JMX Runtime TabJMX Notifications Tab Using the Functions in the JMX Server View MBean Filter MBean Attribute Tab MBean Operations Tab 10 MBean Operations Tab Open for Display MBean Notifications Tab MBean Information Tab 12 MBean Information Tab Open for Display Profiling Applications Profiling Overview Tuning Performance TracingSampling Preparing a Benchmark Collecting Profile Data Profiling with -Xeprof If timeon=sig... has not been specified, the default is Profiling with Zero Preparation Profiling with -agentlibhprof Following options are useful Supported -agentlibhprofoptions Naming Profile Data Files Generate more complete call graphs Inclusive Method CPU Times Profiling with -Xeprof Profiling with -agentlibhprof Approaches to Analyzing Performance Data Considerations in Interpreting the DataLooking at the Data from the Bottom Up Looking at the Data from the Top Down Locating Summary Information for Saved Data Sets Inclusive Versus Exclusive TimeTime Units CPU Versus Clock Time Adjusting Scope Estimate menus Comparing Profiling Data Files Scaling Comparison Data Reading Profiling Histograms Key to Thread States Reported by Interpreting the Histogram Presentation Using Call Graph Trees Interpreting Call Graph Data Example of Node Color Display Using Sub-Trees Options for Manipulating the Call Tree DisplayTree Pruning Auto-Expanding the Call Tree Using Heuristics to Locate Possible Hot Spots Searching the Trees Using Heuristics to Locate Possible Hot Spots Analyzing Garbage Collection Data Obtaining Garbage Collection DataData Collection with -Xverbosegc Java ... -Xverbosegchelp 13, Old generation, in bytes. These spaces are reported Collecting GC Data with Zero Preparation Collecting Glance Data for Viewing in HPjmeter Data Collection with -Xloggc Related Topics Using -XX+PrintGCDetails and -XX+PrintHeapAtGC Together Naming GC Data Files Comparing Garbage Collection Data Files Basic Garbage Collection Concepts Key to Garbage Collection Types Recognized by HPjmeter Understanding the Summary Presentation of GC Data Common Garbage Collection Types Recognized by HPjmeter Summary Panel Showing Garbage Collection Statistics Understanding the System Details Captured with GC Data Basic Garbage Collection Concepts Analyzing Garbage Collection Data Using the Console Using the Main Window FunctionsStarting the Console Data Representation Main Console Window Icons and Their Meaning Node AgentJVM Agent Open and Cached Sessions Time Slice EntriesSaving Data Console Tool Bar Buttons Console Menu Choices Monitor Menu Remember Main Window Location Console Guide Console Guide Location and First Screen Setting Monitoring Session Preferences Status BarSpecifying Metrics to Collect for Monitoring Enabling Monitoring Alerts Specifying Filters for Monitoring Editing FiltersAdding Filters Using Alerts Viewing Monitoring Data in HPjmeterSpecifying Filter Sets Appearance of Alert Threshold in GC Duration Visualizer Using the Alert Controller Appearance of Alert Notices in the Main Console Pane Alert Controller Window Editing E-mail Notification Attributes Viewing a Log of the Alert History Responding to Alerts Abnormal Thread Termination Alert Identifying Abnormal Thread Termination Thread Histogram Expected Out Of Memory Error Alert Excessive Compilation AlertGC Duration Notification Heap Usage Notification Java Collection Leak Locations Alert Array Leak Locations Alert 13 Java Collection Leak Locations Visualizer Process CPU Usage Alert 14 Array Leak Locations Visualizer System CPU Usage Alert Thread Deadlock Alert Unfinalized Queue Growth Using Visualizer Functions Profiling Data Viewer Using Monitoring Displays Locating Information About a JVM and its Environment Monitor Code and/or CPU Activity Menu Java Method HotSpots Details Thrown Exceptions Thrown Exceptions with Stack Traces Monitoring Metric Thrown Exceptions with Stack Traces Monitor Memory and/or Heap Activity Menu Heap Monitor Garbage Collections Monitoring Metric 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 Monitor Threads and/or Locks Menu Thread Histogram Already acquired by another thread Lock Contention 14 Monitoring Metric Lock Contention Monitor JVM and/or System Activity Menu Method Compilation Count Method Compilation Frequency Loaded Classes Percent % CPU Utilization 17 Monitoring Metric Loaded Classes Related Topics Using Profile Displays Viewing Profiling or GC Data in HPjmeter Using Visualizer Functions Inline Candidates Exceptions Thrown Memory Leaks Menu Choices Profile Code and/or CPU ActivityMethod Call Count Exclusive Method Times CPU Exclusive Method Clock TimesCall Graph Tree with Call Count Call Graph Tree with CPU Call Graph Tree with Clock TimeInclusive Method CPU Times Inclusive Method Clock Times Average Exclusive Method Clock Times Average Inclusive Method CPU TimesAverage Inclusive Method Clock Times Starvation by Method Profile Memory and/or Heap Activity Starvation RatioMethods with Loops Exclusive Class CPU Times Objects Created by Method Created Objects CountCreated Objects Bytes Live Objects Count Reference Graph Tree Reference Sub-Trees by Size Using Profile Displays For string and char arrays, see String and char arrays 21 Long String Pop-up Box Class Loaders 23 Class Loaders Visualizer 24 Class Types Pop-up Window Guidelines Profile by Threads Residual Objects CountResidual Objects Bytes Threads Histogram Profile by Locks Thread Groups Histogram Lock Delay Method Exclusive Lock Delay Call Graph TreeContested Lock Claims by Method All Lock Claims by Method Lock Delay Method Inclusive Lock Contention Ratio by MethodAverage Exclusive Method Lock Delay Exclusive Method Lock Delay / Clock Time Using Heuristic Metrics from the Estimate Menu Exclusive Class Lock DelayInline Candidates Exceptions Thrown Using Specialized Garbage Collection Displays Heap Usage After GC Duration Stop the World 27 GC Metric Heap Usage After GC Related Topics Cumulative Allocation 28 GC Metric Duration Related Topics Creation Rate 29 GC Metric Cumulative Allocation Related Topics Allocation Site Statistics 30 GC Metric Creation Rate Related Topics 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 Multiple User-Defined 37 User-Defined Comparisons of GC Metrics Related Topics 38 Multiple User-Defined Metrics Glance Data 40 GC Metric Glance Data 41 Glance Data Metric Configuration Box Run Queue Average Glance System Call Data Are private 42 GC Metric Glance System Call Data Using Visualizer Tool Bars Common Tool Bar Buttons Tool Bar Buttons for Manipulating Tabular Data Tool Bar Buttons for Manipulating Graphical DataTool Bar Buttons for Manipulating Garbage Collection Data Special Button or Other Gadget Functions Mark an Item for Search Find a Search Pattern 44 Locating an Item Pause or Resume Graphical Time-based Scrolling Changing Time Interval in GC Data Visualizers 46 The View Menu Selections in the GC Viewer Using Visualizer Tool Bars Changing Time Interval in Monitoring Visualizers Change Color Selection for Histogram Display 50 Time Interval Use in a Monitoring Visualizer Thread Histogram Profile by Threads Understanding How HPjmeter Works Performance Overhead on Running Applications Using Confidence Interval to Indicate Sample Validity Data Sampling ConsiderationsConsole Overhead How Memory Leak Detection Works Related Topics Page Troubleshooting InstallationDocumentation and Support Identifying Version Numbers Console See also To Take Advantage of Dynamic Attach If you see this JVM agent error on startup JVM agent Node agent Zero Preparation Profiling Unexpected Behavior in Visualizers Connecting to the HPjmeter Node Agent Quick References Start and stop verbose GC data 0.14 0.02 Active mode Glossary Jvmpi SSL Symbols Index 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