Generated classes not compatible with Confluent Kafka client producer

[bhaeussermann]

I generate a class from an Avro schema as follows:

var schema = new JsonSchemaReader().Read(schemaString);
var codeGenerator = new CSharpCodeGenerator();
var compilationUnitSyntax = codeGenerator.GenerateCompilationUnit(schema);
// ... Compile to an assembly using CSharpCompilation.

I would like to use the resulting class to produce messages using a Confluent.Kafka.IProducer. However, an instance of this class cannot be used like this as the class doesn't implement ISpecificRecord which is required by the producer implementation (the resulting exception is System.InvalidOperationException : AvroSerializer only accepts type parameters of int, bool, double, string, float, long, byte[], instances of ISpecificRecord and subclasses of SpecificFixed.)

If, on the other hand, I generate the class using Apache.Avro like so:

var codeGenerator = new Avro.CodeGen();
codeGenerator.AddSchema(schema);
var codeCompileUnit = codeGenerator.GenerateCode();

and compile this to an assembly and reflect the class to use an instance of it with a producer, that works because in this case the generated class does implement ISpecificRecord.

I'm puzzled as to why the classes generated by Chr.Avro don't implement ISpecificRecord. Chr.Avro is supposed to integrate seamlessly with Confluent's Kafka client, but the generated class does not work with Confluent.Kafka.IProducer 🤔. What am I missing?

[dstelljes]

Hey Bernhard, ISpecificRecord is an Apache.Avro interface. Chr.Avro and Apache.Avro are totally separate implementations; you should use serializers from Chr.Avro.Confluent instead of the default Avro serializer. We have some examples here: https://engineering.chrobinson.com/dotnet-avro/guides/kafka/