The issue is https://issues.apache.org/jira/browse/FLINK-3088.
On Fri, Nov 27, 2015 at 12:21 PM, Till Rohrmann <trohrm...@apache.org> wrote: > Hi Martin, > > I think the problem is that the the WritableSerializer, WritableComparator, > ValueComparator, ValueSerializer and the AvroSerializer all use Kryo to > copy objects. However, in some cases, e.g. missing no-arg constructor, > Kryo is not able to copy the object. In these cases, one should try to > copy the objects via serialization as a fallback strategy. That’s a bug in > these components. I’ll file an issue and open a PR for it. > > Thanks a lot for finding this problem Martin! > > Cheers, > Till > > > On Fri, Nov 27, 2015 at 11:59 AM, Martin Junghanns < > m.jungha...@mailbox.org> wrote: > >> Hi, >> >> I looked further into the problem and discovered, that the serialization >> also fails for TestEnvironment and LocalEnvironment if a groupBy operation >> is involved. >> >> Please have a look at the updated Gist >> >> https://gist.github.com/s1ck/566796df5f35ee1de6f9 >> >> Best, >> Martin >> >> >> On 27.11.2015 10:20, Martin Junghanns wrote: >> >>> Hi, >>> >>> While building IT tests which extend MultipleProgramsTestBase, I >>> encountered a problem with serialization: >>> >>> I posted a minimal example here: >>> https://gist.github.com/s1ck/566796df5f35ee1de6f9 >>> >>> This runs fine with LocalEnvironment. However, when executing this in >>> CollectionEnvironment, it leads to the following Exception: >>> >>> Exception in thread "main" com.esotericsoftware.kryo.KryoException: >>> Class cannot be created (missing no-arg constructor): java.util.UUID >>> Serialization trace: >>> uuid (ObjectInTuple$ID) >>> at >>> >>> com.esotericsoftware.kryo.Kryo$DefaultInstantiatorStrategy.newInstantiatorOf(Kryo.java:1228) >>> >>> >>> I tried to manually register a UUIDSerializer (which should not be >>> necessary as Flink has a dependency to such "default" serializers), but >>> this did not fix the problem. >>> >>> What I don't understand in general is why the LocalEnvironment and the >>> CollectionEnvironment use different strategies (e.g. in serialization >>> and also in workflow execution). >>> >>> Thanks for your help! >>> >>> Best, >>> Martin >>> >> >
