Analyzing heap and core dumps

Tools and Analysis

Eclipse Memory Analyzer - Use for Out of Memory or leak issues

Install Eclipse Memory Analyzer as eclipse plugin

Install IBM Diagnostic Tool Framework as eclipse plugin - required to be able to open IBM's Java VM type of dump files. .phd

• .phd files - Summary information of objects. This is a much smaller file and requires less memory to open and process the file.

  • Use Eclipse file open... to open the .phd file

• .dmp files - Contains entire dump of memory including every value of all objects and properties.

  • You will need to set your eclipse heap size a few GB larger than the size of the dump file
  • Use Eclipse file open... to open the .dmp file

Getting Started

The tooling is activated in Eclipse by using file open... to open a .phd or .dmp file.

Further usage details can be found here - documentation

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Garbage Collection and Memory Visualizer - view issues related to garbage collection over time

Install GCMV as eclipse plugin

• .trc files - A trace file for garbage collection data over time

Getting Started

The tooling is activated in Eclipse by opening perspective Health Center Garbage Collection and then using File -> Load Data... to open a .trc file.

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IBM Thread and Dump Monitor Analyzer - analyze core dumps for crash determination

Download JAR file

• javacore.*.txt files - Contains reason core was created and stack traces of all threads

Getting Started

• Run the tool using java -jar jca457.jar
• Use File -> open thread dumps to open the javacore.*.txt file
• Click on the thread dump in the Thread Dump List
• Look for line Cause of thread dump

Further usage details - documentation

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Additional References

OpenJ9 Diagnostics Information

Native OOME