An internal error occurred during: "default_report org.eclipse.mat.api:suspects". Java heap space

[eclipsewebmaster]

| --- | --- |
| Bugzilla Link | 433480 |
| Status | NEW |
| Importance | P3 normal |
| Reported | Apr 24, 2014 21:31 EDT |
| Modified | May 15, 2014 13:18 EDT |
| Reporter | kinya yamada |

Description

OS:Window 7 professional
JDK:jdk1.7.0_21 64bit
mat Ver :MemoryAnalyzer-1.3.1.20140107-win32.win32.x86_64

MemoryAnalyzer.int
[
-startup
plugins/org.eclipse.equinox.launcher_1.2.0.v20110502.jar
--launcher.library
plugins/org.eclipse.equinox.launcher.win32.win32.x86_64_1.1.100.v20110502
-vm
C:\Program Files\Java\jdk1.7.0_21\bin\java
-vmargs
-Xmx4g
]

I open a dump with 1.5G size and to open leak suspect report
but the following error occurred.
[
An internal error occurred during: "default_report org.eclipse.mat.api:suspects".　Java heap space
]

[eclipsewebmaster]

By kinya yamada on Apr 24, 2014 21:33

And MY PC's RAM is 8G Byte

[eclipsewebmaster]

By Andrew Johnson on Apr 25, 2014 10:33

What is the exact stack trace of the error from Window > Error Log.
What kind of dump is it (HPROF?, PHD?).
The dump should have been parsed, so can you close the dump, then reopen it without running any report?
Does the error recur if you then run the leak suspects report?

[eclipsewebmaster]

By kinya yamada on Apr 25, 2014 11:45

(In reply to Andrew Johnson from comment #2)

What is the exact stack trace of the error from Window > Error Log.

I will upload it on April 28

What kind of dump is it (HPROF?, PHD?).

It is　HPROF

The dump should have been parsed, so can you close the dump, then reopen it
without running any report?

Yes　other report can open without any problem.

Does the error recur if you then run the leak suspects report?

YES ,run the leak suspects report
and the dialog error window shows
[
An internal error occurred during: "default_report org.eclipse.mat.api:suspects".　Java heap space
]

[eclipsewebmaster]

By Andrew Johnson on May 12, 2014 16:09

Opening a 1829MB IBM core file (Objects: 6,222,655 Heap size: 568,182,763) with Memory Analyzer with -Xmx300m and running the leak suspects report gave
me the following error.

eclipse.buildId=unknown
java.version=1.8.0_05
java.vendor=Oracle Corporation
BootLoader constants: OS=win32, ARCH=x86_64, WS=win32, NL=en_GB
Command-line arguments: -os win32 -ws win32 -arch x86_64

Error
Mon May 12 12:49:24 BST 2014
An internal error occurred during: "default_report org.eclipse.mat.api:suspects".

java.lang.OutOfMemoryError: Java heap space
at org.eclipse.mat.parser.internal.snapshot.MultiplePathsFromGCRootsComputerImpl.bfs(MultiplePathsFromGCRootsComputerImpl.java:174)
at org.eclipse.mat.parser.internal.snapshot.MultiplePathsFromGCRootsComputerImpl.computePaths(MultiplePathsFromGCRootsComputerImpl.java:82)
at org.eclipse.mat.parser.internal.snapshot.MultiplePathsFromGCRootsComputerImpl.getPathsByGCRoot(MultiplePathsFromGCRootsComputerImpl.java:107)
at org.eclipse.mat.inspections.LeakHunterQuery.findCommonPathForSuspects(LeakHunterQuery.java:864)
at org.eclipse.mat.inspections.LeakHunterQuery.execute(LeakHunterQuery.java:160)
at org.eclipse.mat.query.registry.ArgumentSet.execute(ArgumentSet.java:132)
at org.eclipse.mat.query.registry.CommandLine.execute(CommandLine.java:93)
at org.eclipse.mat.report.internal.QueryPart.execute(QueryPart.java:96)
at org.eclipse.mat.report.internal.SectionPart.execute(SectionPart.java:61)
at org.eclipse.mat.report.TestSuite.execute(TestSuite.java:129)
at org.eclipse.mat.report.internal.RunRegisterdReport.execute(RunRegisterdReport.java:50)
at org.eclipse.mat.query.registry.ArgumentSet.execute(ArgumentSet.java:132)
at org.eclipse.mat.ui.QueryExecution$ExecutionJob.run(QueryExecution.java:180)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:53)

[eclipsewebmaster]

By Andrew Johnson on May 13, 2014 12:47

I ran a leak suspects report on a dump generated by MAT itself in comment 4, and also looked at the memory occupied by Strings.
Perhaps Field names should be commoned as Fields retain 82MB.

Class Name | Objects | Shallow Heap | Retained Heap
-------------------------------------------------------------------------------------------------
java.lang.String | 895,992 | 21,503,808 | 77,016,440
|- org.eclipse.mat.snapshot.model.Field | 673,874 | 16,172,976 | 82,813,408
|- org.eclipse.mat.parser.model.ClassImpl | 39,560 | 4,114,240 | 99,361,096
|- java.util.HashMap$Node | 65,135 | 2,084,320 | 12,597,488
| |- java.util.HashMap$Node[] | 8,114 | 664,496 | 13,087,752
| | |- java.util.HashMap | 8,111 | 389,328 | 13,123,016
| | |- org.eclipse.emf.ecore.impl.EPackageRegistryImpl| 2 | 96 | 1,216
| | |- java.lang.ProcessEnvironment | 1 | 48 | 2,288
| | '- Total: 3 entries | | |
| |- java.util.HashMap$Node | 12,772 | 408,704 | 4,562,736
| '- Total: 2 entries | | |
|- org.eclipse.mat.snapshot.model.FieldDescriptor | 79,389 | 1,905,336 | 7,157,904\

[eclipsewebmaster]

By Andrew Johnson on May 15, 2014 13:15

Another way a lot of memory could be used is in the Paths2GCroots query. From the same dump above I found the following.
There 910,811 path entries held in 862.336 FIFO entries. Only a few of those paths are used in the HTML report.

Class Name | Shallow Heap | Retained Heap
-----------------------------------------------------------------------------------------------------------------------------------------
org.eclipse.mat.internal.snapshot.inspections.Path2GCRootsQuery$Tree @ 0xf702e058 | 32 | 44,130,232
|- class org.eclipse.mat.internal.snapshot.inspections.Path2GCRootsQuery$Tree @ 0xf702dfe0 | 0 | 0
|- snapshot org.eclipse.mat.parser.internal.SnapshotImpl @ 0xf2e0e618 | 64 | 114,966,536
|- computer org.eclipse.mat.parser.internal.SnapshotImpl$PathsFromGCRootsComputerImpl @ 0xf6eb2030 | 80 | 44,113,160
| |- class org.eclipse.mat.parser.internal.SnapshotImpl$PathsFromGCRootsComputerImpl @ 0xf6f6ff38| 0 | 0
| |- this$0 org.eclipse.mat.parser.internal.SnapshotImpl @ 0xf2e0e618 | 64 | 114,966,536
| |- inboundIndex org.eclipse.mat.parser.index.IndexReader$InboundReader @ 0xf2ea3dc0 | 32 | 10,240
| |- excludeMap java.util.HashMap @ 0xf6eb1bc0 | 48 | 1,440
| |- fifo java.util.LinkedList @ 0xf6eb2080 | 32 | 42,555,560
| |- visited org.eclipse.mat.collect.BitField @ 0xf6eb20a0 | 16 | 777,864
| |- excludeInstances org.eclipse.mat.collect.BitField @ 0xf6eb20b0 | 16 | 777,864\