11/28/2017 14:53:28     latest_time -> (cassandra-map -> Sink: cassandra-active-sink, map_active_stream, map_history_stream)(1/1) switched to FAILED
java.lang.IllegalStateException: Could not initialize keyed state backend.
        at org.apache.flink.streaming.api.operators.AbstractStreamOperator.initKeyedState(AbstractStreamOperator.java:321)
        at org.apache.flink.streaming.api.operators.AbstractStreamOperator.initializeState(AbstractStreamOperator.java:217)
        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:745)
Caused by: java.io.InvalidClassException: lab.vardata.events.AirTrafficEventWithId; local class incompatible: stream classdesc serialVersionUID = 8728793377341765980, local class serialVersionUID = -4253404384162522764
        at java.io.ObjectStreamClass.initNonProxy(ObjectStreamClass.java:616)
        at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1623)
        at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1518)
        at java.io.ObjectInputStream.readClass(ObjectInputStream.java:1484)
        at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1334)
        at java.io.ObjectInputStream.readObject(ObjectInputStream.java:371)
        at org.apache.flink.util.InstantiationUtil.deserializeObject(InstantiationUtil.java:305)
        at org.apache.flink.api.java.typeutils.runtime.TupleSerializerConfigSnapshot.read(TupleSerializerConfigSnapshot.java:64)
        at org.apache.flink.api.common.typeutils.TypeSerializerSerializationUtil$TypeSerializerConfigSnapshotSerializationProxy.read(TypeSerializerSerializationUtil.java:510)
        at org.apache.flink.api.common.typeutils.TypeSerializerSerializationUtil.readSerializerConfigSnapshot(TypeSerializerSerializationUtil.java:315)
        at org.apache.flink.api.common.typeutils.TypeSerializerSerializationUtil.readSerializersAndConfigsWithResilience(TypeSerializerSerializationUtil.java:271)
        at org.apache.flink.runtime.state.KeyedBackendStateMetaInfoSnapshotReaderWriters$KeyedBackendStateMetaInfoReaderV3.readStateMetaInfo(KeyedBackendStateMetaInfoSnapshotReaderWriters.java:198)
        at org.apache.flink.runtime.state.KeyedBackendSerializationProxy.read(KeyedBackendSerializationProxy.java:130)
        at org.apache.flink.runtime.state.heap.HeapKeyedStateBackend.restorePartitionedState(HeapKeyedStateBackend.java:432)
        at org.apache.flink.runtime.state.heap.HeapKeyedStateBackend.restore(HeapKeyedStateBackend.java:397)
        at org.apache.flink.streaming.runtime.tasks.StreamTask.createKeyedStateBackend(StreamTask.java:772)
        at org.apache.flink.streaming.api.operators.AbstractStreamOperator.initKeyedState(AbstractStreamOperator.java:311)
        ... 6 more