In recent ClickHouse versions (21.3) Avro format for kafka does not work at all.
In ClickHouse 20.3 one Avro formatted kafka message can read, than stall forever.
Reportedly in ClickHouse prior 20.3 Avro formatted kafka messages work Ok while contain only single record
{
                field_skip_fns.push_back(createSkipFn(root_node->leafAt(i)));
            }
            return [field_skip_fns](avro::Decoder & decoder)
            {
                for (const auto & skip_fn : field_skip_fns)
                    skip_fn(decoder);
            };
        }
        case avro::AVRO_SYMBOLIC:
        {
            auto [it, inserted] = symbolic_skip_fn_map.emplace(root_node->name(), SkipFn{});
            if (inserted)
            {
                it->second = createSkipFn(avro::resolveSymbol(root_node));
            }
            return [&skip_fn = it->second](avro::Decoder & decoder)
            {
                skip_fn(decoder);
            };
        }
        default:
            throw Exception("Unsupported Avro type " + root_node->name().fullname() + " (" + toString(int(root_node->type())) + ")", ErrorCodes::ILLEGAL_COLUMN);
    }
}
static inline std::string concatPath(const std::string & a, const std::string & b)
{
    return a.empty() ? b : a + "." + b;
}
AvroDeserializer::Action AvroDeserializer::createAction(const Block & header, const avro::NodePtr & node, const std::string & current_path)