I have a very simple Flink Streaming job that basically consumes 2 records from a topic (r1 with schema s1 and r2 with schema s2, both s1 and s2 are backward+forward compatible).
Schema definition: s2 has 1 field extra than s1.
I'm trying to make the FlinkKafkaConsumer run using ConfluentRegistryAvroSerializationSchema.forGeneric(), which takes in s1 as reader schema and also schema registry URL, it doesn't work. The deserializer just ignores the additional column as the reader schema doesn't have it. How is schema registry being useful here?
Additionally, I tried writing a custom wrapper for KafkaAvroDeserializer referring this: Is it possible to deserialize Avro message(consuming message from Kafka) without giving Reader schema in ConfluentRegistryAvroDeserializationSchema. This solution explores using only the writer schema without reader schema provided - which is exactly what I need.
This gives me another runtime exception with Flink as follows:
Caused by: com.esotericsoftware.kryo.KryoException: java.lang.UnsupportedOperationException
Serialization trace:
reserved (org.apache.avro.Schema$Field)
fieldMap (org.apache.avro.Schema$RecordSchema)
schema (org.apache.avro.generic.GenericData$Record)
at com.esotericsoftware.kryo.serializers.ObjectField.read(ObjectField.java:125)
at com.esotericsoftware.kryo.serializers.FieldSerializer.read(FieldSerializer.java:528)
at com.esotericsoftware.kryo.Kryo.readClassAndObject(Kryo.java:761)
at com.esotericsoftware.kryo.serializers.MapSerializer.read(MapSerializer.java:143)
at com.esotericsoftware.kryo.serializers.MapSerializer.read(MapSerializer.java:21)
at com.esotericsoftware.kryo.Kryo.readObject(Kryo.java:679)
at com.esotericsoftware.kryo.serializers.ObjectField.read(ObjectField.java:106)
at com.esotericsoftware.kryo.serializers.FieldSerializer.read(FieldSerializer.java:528)
at com.esotericsoftware.kryo.Kryo.readObject(Kryo.java:679)
at com.esotericsoftware.kryo.serializers.ObjectField.read(ObjectField.java:106)
at com.esotericsoftware.kryo.serializers.FieldSerializer.read(FieldSerializer.java:528)
at com.esotericsoftware.kryo.Kryo.readClassAndObject(Kryo.java:761)
at org.apache.flink.api.java.typeutils.runtime.kryo.KryoSerializer.deserialize(KryoSerializer.java:354)
at org.apache.flink.streaming.runtime.streamrecord.StreamElementSerializer.deserialize(StreamElementSerializer.java:191)
at org.apache.flink.streaming.runtime.streamrecord.StreamElementSerializer.deserialize(StreamElementSerializer.java:46)
at org.apache.flink.runtime.plugable.NonReusingDeserializationDelegate.read(NonReusingDeserializationDelegate.java:53)
at org.apache.flink.runtime.io.network.api.serialization.NonSpanningWrapper.readInto(NonSpanningWrapper.java:337)
at org.apache.flink.runtime.io.network.api.serialization.SpillingAdaptiveSpanningRecordDeserializer.readNonSpanningRecord(SpillingAdaptiveSpanningRecordDeserializer.java:128)
at org.apache.flink.runtime.io.network.api.serialization.SpillingAdaptiveSpanningRecordDeserializer.readNextRecord(SpillingAdaptiveSpanningRecordDeserializer.java:103)
at org.apache.flink.runtime.io.network.api.serialization.SpillingAdaptiveSpanningRecordDeserializer.getNextRecord(SpillingAdaptiveSpanningRecordDeserializer.java:93)
at org.apache.flink.streaming.runtime.io.AbstractStreamTaskNetworkInput.emitNext(AbstractStreamTaskNetworkInput.java:95)
at org.apache.flink.streaming.runtime.io.StreamOneInputProcessor.processInput(StreamOneInputProcessor.java:65)
at org.apache.flink.streaming.runtime.tasks.StreamTask.processInput(StreamTask.java:496)
at org.apache.flink.streaming.runtime.tasks.mailbox.MailboxProcessor.runMailboxLoop(MailboxProcessor.java:203)
at org.apache.flink.streaming.runtime.tasks.StreamTask.runMailboxLoop(StreamTask.java:809)
at org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:761)
at org.apache.flink.runtime.taskmanager.Task.runWithSystemExitMonitoring(Task.java:958)
at org.apache.flink.runtime.taskmanager.Task.restoreAndInvoke(Task.java:937)
at org.apache.flink.runtime.taskmanager.Task.doRun(Task.java:766)
at org.apache.flink.runtime.taskmanager.Task.run(Task.java:575)
at java.lang.Thread.run(Thread.java:750)
Caused by: java.lang.UnsupportedOperationException
at java.util.Collections$UnmodifiableCollection.add(Collections.java:1057)
at com.esotericsoftware.kryo.serializers.CollectionSerializer.read(CollectionSerializer.java:109)
at com.esotericsoftware.kryo.serializers.CollectionSerializer.read(CollectionSerializer.java:22)
at com.esotericsoftware.kryo.Kryo.readObject(Kryo.java:679)
at com.esotericsoftware.kryo.serializers.ObjectField.read(ObjectField.java:106)
... 30 more
How do I make this work and understand the core concept of schema registry better?
