Hello friends. I recently noticed that one of our state classes was falling back to kryo serialization. This was because it is using a java

Map

as one of the fields and flink is unable to derive the types. To resolve the issue, I defined a

TypeInfoFactory

and annotated the class

@TypeInfo(classOf[MyNewTypeInfoFactory])

. Unit tests confirmed that the class would now appropriately use the

PojoSerializer

. However, when I test deploying and loading from a snapshot, I receive the error:

The new state serializer must not be incompatible with the old state serializer.

Does anyone have suggestions regarding how to debug why the serializers are incompatible? None of the underlying data structures have been modified. Is it possible to write a unit test for this kind of thing?

https://docs.immerok.cloud/docs/how-to-guides/development/migrating-state-away-from-kryo/ is a good resource on this topic.

Thanks friend. Reading through this now.

Happy to hear you got it working! The Kryo serializer can be rather verbose, especially if you haven't registered your types.