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
return [](avro::Decoder & decoder) { decoder.decodeInt(); };
        case avro::AVRO_LONG:
            return [](avro::Decoder & decoder) { decoder.decodeLong(); };
        case avro::AVRO_FLOAT:
            return [](avro::Decoder & decoder) { decoder.decodeFloat(); };
        case avro::AVRO_DOUBLE:
            return [](avro::Decoder & decoder) { decoder.decodeDouble(); };
        case avro::AVRO_BOOL:
            return [](avro::Decoder & decoder) { decoder.decodeBool(); };
        case avro::AVRO_ARRAY:
        {
            auto nested_skip_fn = createSkipFn(root_node->leafAt(0));
            return [nested_skip_fn](avro::Decoder & decoder)
            {
                for (size_t n = decoder.arrayStart(); n != 0; n = decoder.arrayNext())
                {
                    for (size_t i = 0; i < n; ++i)
                    {
                        nested_skip_fn(decoder);
                    }
                }
            };
        }
        case avro::AVRO_UNION:
        {
            std::vector<SkipFn> union_skip_fns;
            for (size_t i = 0; i < root_node->leaves(); i++)
            {
                union_skip_fns.push_back(createSkipFn(root_node->leafAt(i)));
            }