Java Heap Dump error - Metadata does not appear to be polymorphic

Question

I get this Stacktrace when trying to take a heap dump from a running Java process. What causes this and what do I have to do to make a proper heap dump?

Dum         


        

Answer 1

On Ubuntu, I resolved this issue by installing the openjdk-dbg package:

sudo apt-get install openjdk-8-dbg

I now suspect that this resolved my issue indirectly by upgrading the jdk to a version that corrected the bug. You might be able to resolve this issue with:

 sudo apt-get install openjdk-8

Note: After java is upgraded, you must restart the java process in order to get a proper dump. If you don't, you will get something like this:

Attaching to process ID 21957, please wait...
Exception in thread "main" java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at sun.tools.jmap.JMap.runTool(JMap.java:201)
    at sun.tools.jmap.JMap.main(JMap.java:130)
Caused by: sun.jvm.hotspot.debugger.UnmappedAddressException: 7f21453c9bf8
    at sun.jvm.hotspot.debugger.PageCache.checkPage(PageCache.java:208)
    at sun.jvm.hotspot.debugger.PageCache.getData(PageCache.java:63)
    at sun.jvm.hotspot.debugger.DebuggerBase.readBytes(DebuggerBase.java:225)
    at sun.jvm.hotspot.debugger.linux.LinuxDebuggerLocal.readCInteger(LinuxDebuggerLocal.java:498)
    at sun.jvm.hotspot.debugger.linux.LinuxAddress.getCIntegerAt(LinuxAddress.java:69)
    at sun.jvm.hotspot.HotSpotTypeDataBase.getLongValueFromProcess(HotSpotTypeDataBase.java:604)
    at sun.jvm.hotspot.HotSpotTypeDataBase.readVMTypes(HotSpotTypeDataBase.java:164)
    at sun.jvm.hotspot.HotSpotTypeDataBase.(HotSpotTypeDataBase.java:89)
    at sun.jvm.hotspot.HotSpotAgent.setupVM(HotSpotAgent.java:395)
    at sun.jvm.hotspot.HotSpotAgent.go(HotSpotAgent.java:305)
    at sun.jvm.hotspot.HotSpotAgent.attach(HotSpotAgent.java:140)
    at sun.jvm.hotspot.tools.Tool.start(Tool.java:185)
    at sun.jvm.hotspot.tools.Tool.execute(Tool.java:118)
    at sun.jvm.hotspot.tools.HeapDumper.main(HeapDumper.java:83)
    ... 6 more