Avro logical types and Schema Registry

[Tianxiang Xiong]

I'd like to add a UUID type to Avro.

From the mailing lists, the suggested approach is to define a logical type:

{ "type": "string", "logicalType": "uuid" }

However, the discussion here suggests this approach would not work properly. Is there more information on whether this is the case, and, if so, why? 

Is there an example of a logical type being specified for an Avro schema used by the schema registry? Can we extend the Schema Registry's parser to do conversions of logical types automatically, or does client code have to handle this?