Java内存不足错误

Question

I am seeing an OutOfMemory problem and I am not sure it is the PERM GEN area or the heap space. The error message does not say anything about which area ran out of memory.

Here is a partial stack trace: The following is information that may be useful to the developer of BETWEENNESS: java.lang.OutOfMemoryError at java.util.zip.ZipFile.open(Native Method) at java.util.zip.ZipFile.(ZipFile.java:127) at java.util.zip.ZipFile.(ZipFile.java:143) at com..util.internal.ZipFiles.unzip(ZipFiles.java:91) I looked at the heap space just before it ran out of memory using the jmap -heap command:

 using thread-local object allocation.
 Parallel GC with 23 thread(s)

 Heap Configuration:
    MinHeapFreeRatio = 40
    MaxHeapFreeRatio = 70
    MaxHeapSize      = 31675383808 (30208.0MB)
    NewSize          = 1310720 (1.25MB)
    MaxNewSize       = 17592186044415 MB
    OldSize          = 5439488 (5.1875MB)
    NewRatio         = 2
    SurvivorRatio    = 8
    PermSize         = 21757952 (20.75MB)
    MaxPermSize      = 536870912 (512.0MB)

 Heap Usage:
 PS Young Generation
 Eden Space:
    capacity = 9762177024 (9309.9375MB)
    used     = 7286558512 (6949.003707885742MB)
    free     = 2475618512 (2360.933792114258MB)
    74.64071276403028% used
 From Space:
    capacity = 396230656 (377.875MB)
    used     = 340623360 (324.84375MB)
    free     = 55607296 (53.03125MB)
    85.96592788620576% used
 To Space:
    capacity = 398131200 (379.6875MB)
    used     = 0 (0.0MB)
    free     = 398131200 (379.6875MB)
    0.0% used
 PS Old Generation
    capacity = 1992163328 (1899.875MB)
    used     = 1455304512 (1387.8865356445312MB)
    free     = 536858816 (511.98846435546875MB)
    73.05146578825087% used
 PS Perm Generation
    capacity = 418578432 (399.1875MB)
    used     = 418567008 (399.1766052246094MB)
    free     = 11424 (0.010894775390625MB)
    99.99727076238844% used }

And also, I had supplied the following arguments to the JVM: -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=/tmp/ but I do not see any heap.

My questions is why is the heap not being generated and how do I figure out which part of the JVm is getting full.

Thanks.

Answer 1

Your provided information says, that your PermGen is 99% full. And your Heap is already 73% full. So increasing both would not be bad at all.

Further you could activate the garbage collector's logging with -XX:+PrintGCDetails to get detailed information on how your JVM is using memory. Additionally activate -XX:+PrintGCTimeStamps and -XX:+PrintGCDateStamps . -Xloggc:$filename sends the logs to a file, which you could easily analyze with something like IMB PMAT tool or GCViewer .

Additionally you should consider using VisualVM to monitor your application while running.

Besides: A colleague of mine found a smart way to get a heapdump many times faster through gdb:

cat > /tmp/dodump <<EOF
gcore jvm.core
detach
quit
EOF
time gdb --batch --command=/tmp/dodump --pid=`pgrep java`
jmap -dump:format=b,file=jvm.hprof `which java` jvm.core
rm jvm.core
gzip -9 jvm.hprof 

Source

Credits go fully to him.

Answer 2

According to stack trace, OutOfMemoryError happens inside ZipFile.open() native method. This means that the problem has nothing to do with Java Heap size nor with PermGen. It is likely related with ZIP cache which is malloc'ed or mmap'ed internally by JDK library.

Try adding -Dsun.zip.disableMemoryMapping=true JVM option to see if it helps.
How large is ZIP file being opened?