I am running into some issues setting up default values for Avro fields. I have a simple schema as given below:
data.avsc:
{
\"name
The default value of a union corresponds to the first schema of the union (Source). Your union is defined as ["long", "null"] therefor the default value must be a long number. null is not a long number that is why you are getting an error.
If you still want to define null as a default value then put null schema first, i.e. change the union to ["null", "long"] instead.