Hi Guowei, I followed the document, but somehow, I am unable to get a working Java example for Avro state.
So, I tried to simply use the Java SpecificRecords created by Avro Maven Plugin and inject. Now, that works correctly, but I use Avro 1.7.7 since it is the last version that I saw which does not put a serialVersionUid in the generated SpecificRecord. How can I use a Avro SpecificRecord generated by 1.8.0 if it use a serialVersionUid because the moment I change something in the Avro schema and regenerate the SpecificRecord, I will get a class incompatible error when Flink tried to deserialise. Thanks, Sandip > On 25-Jun-2021, at 10:25 AM, Guowei Ma <guowei....@gmail.com> wrote: > > Hi Sandeep > > What I understand is that you want to manipulate the state. So I think you > could use the old schema to read the state first, and then write it to a new > schema, instead of using a new schema to read an old schema format data. > In addition, I would like to ask, if you want to do "State Schema Evolution" > ? Flink currently supports avro+pojo's schema evolution[1], and you don't > need to do this manually. > > [1] > https://ci.apache.org/projects/flink/flink-docs-master/docs/dev/datastream/fault-tolerance/serialization/schema_evolution/#supported-data-types-for-schema-evolution > > <https://ci.apache.org/projects/flink/flink-docs-master/docs/dev/datastream/fault-tolerance/serialization/schema_evolution/#supported-data-types-for-schema-evolution> > > Best, > Guowei > > > On Fri, Jun 25, 2021 at 3:04 AM Sandeep khanzode <sand...@shiftright.ai > <mailto:sand...@shiftright.ai>> wrote: > Hello, > > 1.] Can someone please share a working example of how to read > ValueState<POJO> and MapState<POJO> from a checkpoint and update it? I tried > to assemble a working Java example but there are bit and pieces of info > around. > > 2.] I am using Avro 1.7.7 with Flink for state entities since versions belong > Avro 1.7.7 add a serialVersionUid and then I cannot replace the class with a > new Avro schema seamlessly. If I update the Avro schema, and the Avro Maven > plugin runs, a new class with a new serialVersionUid is created and that > cannot be replaced in the state with the Java exception stating that local > and state copies are different. Any example would be really appreciated. > > Thanks, > Sandip
