Hi Yoel, Thank you for answering my question, really appreciated. However, that brings my mind more questions.
1) As far as I understood from the Flink built-in serialization, if a class is a POJO type wrt the items defined in POJOs section here [1], if an object is an instance of a POJO type class, no need to do anything extra. Serialization can be handled via `PojoSerializer` naively? In our case with `java.utils.UUID`, that class has no no-arguments public constructor which cause the fallback to Kyro I guess? 2) In your suggestion `you could provide a supplier of UUIDGenerator`, I am not sure what exactly you refer here? Something like a lambda which is capable of creating an instance of `UUIDGenerator` on demand, which can be called within open() method? 3) `java.util.UUID` class also implements `java.io.Serializable`, but as far as I understood that does not mean a class implementing `java.io.Serializable` is always be able to be serialized via Flink? At least with the built-in serializers (no referring Kyro)? UUID class is java Serializable, though still seems to be a generic type because does not fall into any of the categories mentioned in [1]? 4) When Kyro fallback is enabled, that means fallback is the last resort if the object can be serialized with [1] https://nightlies.apache.org/flink/flink-docs-master/docs/dev/datastream/fault-tolerance/serialization/types_serialization/ On Wed, Feb 2, 2022 at 6:27 AM Yoel Benharrous <yoel.benharr...@gmail.com> wrote: > > Hi Deniz, > > You could declare UUIDGenerator as a transient field and instanciate it in > the open > function > > Ot if you want to inject any UUIDGenerator you could provide a supplier of > UUIDGenerator that should implement Serializable and invoke it in the open > function. > > > > > On Tue, Feb 1, 2022, 10:01 PM Deniz Koçak <lend...@gmail.com> wrote: >> >> Hi All, >> >> We have a function extending `KeyedCoProcessFunction` and within that >> function implementation. I wanted to keep a class object as a field >> which is simply responsible for generating a UUID. >> >> We disabled Kyro fallback for generic types via >> `env.getConfig().disableGenericTypes()`. >> I am receiving the error below when I pass an instance of >> `UUIDGenerator` to the `KeyedCoProcessFunction` and try to run the >> job. >> >> *********************************************************************************** >> Exception in thread "main" java.lang.UnsupportedOperationException: >> Generic types have been disabled in the ExecutionConfig and type >> java.util.UUID is treated as a generic type. >> *********************************************************************************** >> >> At that point I wonder how can/should I do to pass an instance of >> `UUIDGenerator` to `PrebetModelRequestProcessor` function. >> >> >> ModelRequestProcessor Class: >> ======================================================== >> public class ModelRequestProcessor extends >> KeyedCoProcessFunction<String, CustomerInformation, CustomerRisk, >> ModelRequest> { >> >> protected final UUIDGenerator uuidGenerator; >> >> public PrebetModelRequestProcessor(UUIDGenerator generator) { >> this.uuidGenerator = generator; >> } >> } >> ======================================================== >> >> UUIDGenerator Class: >> ======================================================== >> public class UUIDGenerator implements Serializable { >> >> private static final long serialVersionUID = 42L; >> >> public java.util.UUID generate() { >> return java.util.UUID.randomUUID(); >> } >> } >> ========================================================
