Hi Kien, Thank you for reporting this. Generally, this is currently a restriction with the Scala API. Type serializers are generated anonymous classes when using the Scala API, and therefore is sensitive to the ordering / enclosing class / Scala version / etc. when generating them. We’re discussing a fix for this at the moment, I’ll get back to you once we figure that out.
As for the case you’ve bumped into here, you seem to be failing on one of the key serializers when restoring the timer service. Have you happened to also refactored classes that are used as keys? Maybe what you could try doing, as a means to avoid that for now, is to make sure that the key classes are untouched. Please keep us updated on how this works out for you, I’ll continue to look into it. Thanks, Gordon On 17 August 2017 at 10:46:05 AM, Kien Truong (duckientru...@gmail.com) wrote: Hi, After some refactoring: moving some operator to separate functions/file, I'm encountering a lot of exceptions like these. The logic of the application did not change, and all the refactored operators are stateless, e.g simple map/flatmap/filter. Does anyone know how to fix/avoid/work around this? I'm using FsStateBackend on Flink 1.3.2 Regards, Kien java.lang.ClassNotFoundException: x.x.X$$anon$113$$anon$55 at java.net.URLClassLoader.findClass(URLClassLoader.java:381) at java.lang.ClassLoader.loadClass(ClassLoader.java:424) at java.lang.ClassLoader.loadClass(ClassLoader.java:357) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:348) at org.apache.flink.util.InstantiationUtil$ClassLoaderObjectInputStream.resolveClass(InstantiationUtil.java:64) at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1826) at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1713) at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:2000) at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1535) at java.io.ObjectInputStream.readObject(ObjectInputStream.java:422) at org.apache.flink.util.InstantiationUtil.deserializeObject(InstantiationUtil.java:305) at org.apache.flink.streaming.api.operators.HeapInternalTimerService.restoreTimersForKeyGroup(HeapInternalTimerService.java:321) at org.apache.flink.streaming.api.operators.InternalTimeServiceManager.restoreStateForKeyGroup(InternalTimeServiceManager.java:141) at org.apache.flink.streaming.api.operators.AbstractStreamOperator.initializeState(AbstractStreamOperator.java:496) at org.apache.flink.streaming.api.operators.AbstractUdfStreamOperator.initializeState(AbstractUdfStreamOperator.java:104) at org.apache.flink.streaming.api.operators.AbstractStreamOperator.initializeState(AbstractStreamOperator.java:251) at org.apache.flink.streaming.runtime.tasks.StreamTask.initializeOperators(StreamTask.java:676) at org.apache.flink.streaming.runtime.tasks.StreamTask.initializeState(StreamTask.java:663) at org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:252) at org.apache.flink.runtime.taskmanager.Task.run(Task.java:702) at java.lang.Thread.run(Thread.java:748)
