Hey guys,
I have a suspicion which could be the culprit: Could change the line
KryoSerializer.java:328 to kryo.setReferences(true) and try if the error
still remains? We deactivated the reference tracking and now Kryo shouldn’t
be able to resolve cyclic references properly.
Cheers,
Till
On Mon, Apr 11, 2016 at 11:42 PM, Lisonbee, Todd <todd.lison...@intel.com>
wrote:
> Hi,
>
> I also got this error message when I had private inner classes:
>
> public class A {
> private class B {
> }
> }
>
> I was able to fix by making the inner classes public static:
>
> public class A {
> public static class B {
> }
> }
>
> When I was trying to debug it seemed this error message can be caused by
> several different things.
>
> Thanks,
>
> Todd
>
>
> -----Original Message-----
> From: Hilmi Yildirim [mailto:hilmi.yildi...@dfki.de]
> Sent: Sunday, April 10, 2016 11:36 AM
> To: dev@flink.apache.org
> Subject: Re: Kryo StackOverflowError
>
> Hi,
> I also had this problem and solved it.
>
> In my case I had multiple objects which are created via anonymous classes.
> When I broadcasted these objects, the serializer tried to serialize the
> objects and for that it tried to serialize the anonymous classes. This
> caused the problem.
>
> For example,
>
> class A{
>
> def createObjects() : Array[Object]{
> objects
> for{
> object = new Class{
> ...
> }
> objects.add(object)
> }
> return objects
> }
> }
>
> It tried to serialize "new Class". For that it tried to serialize the
> method createObjects(). And then it tried to serialize class A. To
> serialize class A it tried to serialize the method createObjects. Or
> something like that, I do not remember the details. This caused the
> recursion.
>
> BR,
> Hilmi
>
> Am 10.04.2016 um 19:18 schrieb Stephan Ewen:
> > Hi!
> >
> > Is it possible that some datatype has a recursive structure nonetheless?
> > Something like a linked list or so, which would create a large object
> graph?
> >
> > There seems to be a large object graph that the Kryo serializer
> traverses,
> > which causes the StackOverflowError.
> >
> > Greetings,
> > Stephan
> >
> >
> > On Sun, Apr 10, 2016 at 6:24 PM, Andrew Palumbo <ap....@outlook.com>
> wrote:
> >
> >> Hi Stephan,
> >>
> >> thanks for answering.
> >>
> >> This not from a recursive object. (it is used in a recursive method in
> the
> >> test that is throwing this error, but the the depth is only 2 and there
> are
> >> no other Flink DataSet operations before execution is triggered so it is
> >> trivial.)
> >>
> >> Gere is a Gist of the code, and the full output and stack trace:
> >>
> >> https://gist.github.com/andrewpalumbo/40c7422a5187a24cd03d7d81feb2a419
> >>
> >> The Error begins at line 178 of the "Output" file.
> >>
> >> Thanks
> >>
> >> ________________________________________
> >> From: ewenstep...@gmail.com <ewenstep...@gmail.com> on behalf of
> Stephan
> >> Ewen <se...@apache.org>
> >> Sent: Sunday, April 10, 2016 9:39 AM
> >> To: dev@flink.apache.org
> >> Subject: Re: Kryo StackOverflowError
> >>
> >> Hi!
> >>
> >> Sorry, I don't fully understand he diagnosis.
> >> You say that this stack overflow is not from a recursive/object type?
> >>
> >> Long graphs of operations in Flink usually do not cause
> >> StackOverflowExceptions, because not the whole graph is recursively
> >> processed.
> >>
> >> Can you paste the entire Stack Trace (for example to a gist)?
> >>
> >> Greetings,
> >> Stephan
> >>
> >>
> >> On Sun, Apr 10, 2016 at 4:42 AM, Andrew Palumbo <ap....@outlook.com>
> >> wrote:
> >>
> >>> Hi all,
> >>>
> >>>
> >>> I am working on a matrix multiplication operation for Mahout Flink
> >>> Bindings that uses quite a few chained Flink Dataset operations,
> >>>
> >>>
> >>> When testing, I am getting the following error:
> >>>
> >>>
> >>> {...}
> >>>
> >>> 04/09/2016 22:30:35 CHAIN Reduce (Reduce at
> >>>
> >>
> org.apache.mahout.flinkbindings.blas.FlinkOpABt$.abt_nograph(FlinkOpABt.scala:147))
> >>> -> FlatMap (FlatMap at
> >>>
> >>
> org.apache.mahout.flinkbindings.drm.BlockifiedFlinkDrm.asRowWise(FlinkDrm.scala:93))(1/1)
> >>> switched to CANCELED
> >>> 04/09/2016 22:30:35 CHAIN Partition -> Map (Map at
> >>>
> >>
> org.apache.mahout.flinkbindings.blas.FlinkOpABt$.pairwiseApply(FlinkOpABt.scala:240))
> >>> -> GroupCombine (GroupCombine at
> >>>
> >>
> org.apache.mahout.flinkbindings.blas.FlinkOpABt$.abt_nograph(FlinkOpABt.scala:129))
> >>> -> Combine (Reduce at
> >>>
> >>
> org.apache.mahout.flinkbindings.blas.FlinkOpABt$.abt_nograph(FlinkOpABt.scala:147))(3/3)
> >>> switched to FAILED
> >>> java.lang.StackOverflowError
> >>> at
> >>>
> >>
> com.esotericsoftware.kryo.serializers.ObjectField.write(ObjectField.java:48)
> >>> at
> >>>
> >>
> com.esotericsoftware.kryo.serializers.FieldSerializer.write(FieldSerializer.java:495)
> >>> at com.esotericsoftware.kryo.Kryo.writeObject(Kryo.java:523)
> >>> at
> >>>
> >>
> com.esotericsoftware.kryo.serializers.ObjectField.write(ObjectField.java:61)
> >>> at
> >>>
> >>
> com.esotericsoftware.kryo.serializers.FieldSerializer.write(FieldSerializer.java:495)
> >>> at com.esotericsoftware.kryo.Kryo.writeObject(Kryo.java:523)
> >>> at
> >>>
> >>
> com.esotericsoftware.kryo.serializers.ObjectField.write(ObjectField.java:61)
> >>> at
> >>>
> >>
> com.esotericsoftware.kryo.serializers.FieldSerializer.write(FieldSerializer.java:495)
> >>> at com.esotericsoftware.kryo.Kryo.writeObject(Kryo.java:523)
> >>> at
> >>>
> >>
> com.esotericsoftware.kryo.serializers.ObjectField.write(ObjectField.java:61)
> >>> at
> >>>
> >>
> com.esotericsoftware.kryo.serializers.FieldSerializer.write(FieldSerializer.java:495)
> >>> {...}
> >>>
> >>>
> >>> I've seen similar issues on the dev@flink list (and other places),
> but I
> >>> believe that they were from recursive calls and objects which pointed
> >> back
> >>> to themselves somehow.
> >>>
> >>>
> >>> This is a relatively straightforward method, it just has several Flink
> >>> operations before execution is triggered. If I remove some
> operations,
> >>> eg. a reduce, i can get the method to complete on a simple test however
> >> the
> >>> it will then, of course be numerically incorrect.
> >>>
> >>>
> >>> I am wondering if there is any workaround for this type of problem?
> >>>
> >>>
> >>> Thank You,
> >>>
> >>>
> >>> Andy
> >>>
>
>
> --
> ==================================================================
> Hilmi Yildirim, M.Sc.
> Researcher
>
> DFKI GmbH
> Intelligente Analytik für Massendaten
> DFKI Projektbüro Berlin
> Alt-Moabit 91c
> D-10559 Berlin
> Phone: +49 30 23895 1814
>
> E-Mail: hilmi.yildi...@dfki.de
>
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