Eclipse Community Forums: Memory Analyzer » DTFJ Error Opening Core Dump

Home » Eclipse Projects » Memory Analyzer » DTFJ Error Opening Core Dump

DTFJ Error Opening Core Dump [message #1816032]

Thu, 17 October 2019 13:24

Eclipse User

Hello,

I'm trying to open a WebSphere core.dmp file using Memory Analyzer with DTFJ installed and getting this exception:

java.lang.NoSuchFieldError: J9_JAVA_CLASS_RAM_ARRAY
	at com.ibm.j9ddr.vm29.pointer.helper.J9ClassHelper.isArrayClass(J9ClassHelper.java:72)
	at com.ibm.j9ddr.vm29.j9.gc.GCObjectModel_V1.isIndexable(GCObjectModel_V1.java:188)
	at com.ibm.j9ddr.vm29.j9.gc.GCObjectModel_V1.isIndexable(GCObjectModel_V1.java:182)
	at com.ibm.j9ddr.vm29.j9.gc.GCObjectModel_V1.getSizeInBytesWithHeader(GCObjectModel_V1.java:157)
	at com.ibm.j9ddr.vm29.j9.gc.GCObjectModel_V1.getConsumedSizeInBytesWithHeader(GCObjectModel_V1.java:90)
	at com.ibm.j9ddr.vm29.j9.ObjectModel.getConsumedSizeInBytesWithHeader(ObjectModel.java:199)
	at com.ibm.j9ddr.vm29.j9.gc.GCObjectHeapIteratorAddressOrderedList_V1.advanceScanPointer(GCObjectHeapIteratorAddressOrderedList_V1.java:169)
	at com.ibm.j9ddr.vm29.j9.gc.GCObjectHeapIteratorAddressOrderedList_V1.next(GCObjectHeapIteratorAddressOrderedList_V1.java:244)
	at com.ibm.j9ddr.vm29.j9.walkers.HeapWalker.walk(HeapWalker.java:107)
	at com.ibm.j9ddr.vm29.view.dtfj.java.j9.HeapObjectIterator.hasNext(HeapObjectIterator.java:38)
	at com.ibm.j9ddr.vm29.view.dtfj.java.DTFJJavaHeap$1.hasNext(DTFJJavaHeap.java:106)
	at org.eclipse.mat.dtfj.DTFJIndexBuilder.fill(DTFJIndexBuilder.java:1131)
	at org.eclipse.mat.parser.internal.SnapshotFactoryImpl.parse(SnapshotFactoryImpl.java:222)
	at org.eclipse.mat.parser.internal.SnapshotFactoryImpl.openSnapshot(SnapshotFactoryImpl.java:126)
	at org.eclipse.mat.snapshot.SnapshotFactory.openSnapshot(SnapshotFactory.java:147)
	at org.eclipse.mat.ui.snapshot.ParseHeapDumpJob.run(ParseHeapDumpJob.java:83)
	at org.eclipse.core.internal.jobs.Worker.run(Worker.java:60)

It seems related to this J9 bug: https://github.com/eclipse/openj9/issues/6316

Is this something that should be submitted as a bug under MAT at bugs.eclipse.org or is there another place to submit DTFJ bugs?

Thanks,
Frank

Re: DTFJ Error Opening Core Dump [message #1816426 is a reply to message #1816032]

Tue, 29 October 2019 06:39

Eclipse User

This is a DTFJ bug not an Eclipse Memory Analyzer bug. IBM Diagnostic Tooling Framework for Java is a set of classes which allows analysis of dumps from IBM VMs. There is a separate Eclipse format update site which allow any VM to be used. Unfortunately this has not been updated for over a year.

If you have an IBM support contract for IBM WebSphere Application Server you could try asking IBM for the DTFJ update site to be updated with the latest DTFJ as the old version is stopping you debug your application problems.

You could try asking OpenJ9 what the plans are creating a Eclipse update site including DTFJ, as there is an OpenJ9 DTFJ module

As a work-around you could try replacing the dtfj.jar somewhere under the Eclipse Memory Analyzer directory mat\configuration\org.eclipse.osgi with the latest dtfj.jar from your VM.

Re: DTFJ Error Opening Core Dump [message #1816969 is a reply to message #1816426]

Wed, 13 November 2019 03:17

Eclipse User

Thanks for the tip, Andrew.

I found that dtj.jar and dtfj-interface.jar seemed to have been combined, but I found a dtfj.jar and a j9-ddr.jar in the new VM and replaced both the existing dtfj.jar and dtfj-interface.jar with the new dtfj.jar, and j9-ddr.jar with the new j9-ddr.jar. These were all within the plugins directory, in plugins called com.ibm.dtfj.*.

After this I was able to carry on.

Re: DTFJ Error Opening Core Dump [message #1827929 is a reply to message #1816969]

Wed, 27 May 2020 03:01

Eclipse User

Thanks a lot Dave! That saved my day.

I'll open a case with IBM.

Previous Topic:	Memoryanalyzer.exe won't boot after editing .ini file
Next Topic:	OQL: Why is the returned object not a String but "com.ibm.wps.state.keymanager.ValueImpl"?

Goto Forum:

-=] Back to Top [=-

Current Time: Sat Aug 30 06:55:20 EDT 2025

.:: Contact :: Home ::.

Breadcrumbs

Sign up to our Newsletter