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How To Collect JVM Heap and GC Information Using JRMC And Other Tools? (Doc ID 1379015.1)

Last updated on FEBRUARY 07, 2020

Applies to:

Oracle Fusion Application Toolkit - Version to [Release 1.0]
Information in this document applies to any platform.
***Checked for relevance on 10-JUL-2013***


This document contains guidelines for collecting/reviewing JVM Heap information using JRockit Mission Control for memory related issues.


Troubleshooting Steps

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In this Document
Troubleshooting Steps
 JRockit Management Console
 Console > General
 Console > MBeans
 Console > Runtime > System
 Console > Runtime > Memory
 JRockit Flight Recorder
 JFR > General
 JFR > Memory > Overview
 JFR > Memory > GC General
 JFR > Memory > GC Graph
 JFR > Memory > GC Advanced
 JFR > Memory > Allocation
 JFR > Memory > Heap Contents
 JFR > Memory > Object Statistics
 JFR > Advanced
 JRockit Memory Leak Detector
The JRockit Memory Leak Detector helps you discover memory leaks in a Java application and determine their cause. The JRockit Memory Leak Detector trend analyzer discovers slow leaks, shows detailed heap statistics (including referring types and instances to leaking objects) and allocation sites, and provides a quick drill down to the cause of the memory leak. The Memory Leak Detector uses advanced graphical presentation techniques to make it easier to navigate and understand complex information.

In JVM Browser, you would see a list of WebLogic Server processes. You need to identify the process you intend to analyze using the process ID. You can use GUI tools such as System Monitor (if any) in your server or CL commands such as ps -ef | grep weblogic.Name=bi_server to identify the process name.

A memory leak in Fusion Applications causes the application to run slower over time, because the garbage collector must work harder to free memory. After a while, the JVM throws an out-of-memory error. Note that applications with a small memory leak can sometimes run for days until an out-of-memory error occurs. To look for initial signs of a memory leak, you can take a Flight Recorder recording and check the heap usage after each old collection. A continuously rising memory usage could indicate a memory leak.  You can diagnose memory leaks by using the Memory Leak Detector, which helps you pinpoint the class that causes the memory leak.

 Other tools/methods to collect Heap/GC information
 Command-line tool included with the JRockit JDK that you can use to send diagnostic commands to a running JVM process.

 Execute the following commands from the WLST prompt.

 WebLogic Admin Console
 Follow the below navigation path to view Heap and GC information in WebLogic Admin Console.

WebLogic Admin Console > Environment > Servers > SERVER_INSTANCE > Monitoring > Performance


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