apache/seatunnel · error · SeaTunnelAvroFormatException

UNSUPPORTED_DATA_TYPE

UNSUPPORTED_DATA_TYPE

Error message

SeaTunnel avro format is not supported for this data type [${sqlType}]

What it means

SeaTunnelAvroFormatException with code UNSUPPORTED_DATA_TYPE thrown by AvroToRowConverter.convertField when it encounters a SeaTunnel SQL type it cannot map from Avro to a Row field. The switch over dataType falls into the default branch for types the avro format does not handle (e.g. MAP, some TIME/ARRAY variants depending on version).

Source

Thrown at seatunnel-formats/seatunnel-format-avro/src/main/java/org/apache/seatunnel/format/avro/AvroToRowConverter.java:142

                for (Object o : map.entrySet()) {
                    res.put(
                            convertField(mapType.getKeyType(), ((Map.Entry) o).getKey()),
                            convertField(mapType.getValueType(), ((Map.Entry) o).getValue()));
                }
                return res;
            case ARRAY:
                SeaTunnelDataType<?> basicType = ((ArrayType<?, ?>) dataType).getElementType();
                List<Object> list = (List<Object>) val;
                return convertArray(list, basicType);
            case ROW:
                SeaTunnelRowType subRow = (SeaTunnelRowType) dataType;
                return converter((GenericRecord) val, subRow);
            default:
                String errorMsg =
                        String.format(
                                "SeaTunnel avro format is not supported for this data type [%s]",
                                dataType.getSqlType());
                throw new SeaTunnelAvroFormatException(
                        AvroFormatErrorCode.UNSUPPORTED_DATA_TYPE, errorMsg);
        }
    }

    protected Object convertArray(List<Object> val, SeaTunnelDataType<?> dataType) {
        if (val == null) {
            return null;
        }
        int length = val.size();
        Object instance = Array.newInstance(dataType.getTypeClass(), length);
        for (int i = 0; i < val.size(); i++) {
            Array.set(instance, i, convertField(dataType, val.get(i)));
        }
        return instance;
    }
}

View on GitHub (pinned to cf67b549a7)

Solutions

1. Check which SqlType hit the default branch (in the error message) and avoid that type in the row type for Avro format
2. Convert unsupported fields to STRING before Avro serialization
3. Upgrade to a SeaTunnel version with broader Avro type coverage
4. Extend convertField to handle the type if you control the code

Example fix

// before
SeaTunnelRowType rowType = new SeaTunnelRowType(new String[]{"m"}, new SeaTunnelDataType<?>[]{new MapType<>(STRING_TYPE, INT_TYPE)});
// after
SeaTunnelRowType rowType = new SeaTunnelRowType(new String[]{"m"}, new SeaTunnelDataType<?>[]{STRING_TYPE}); // serialize map as JSON string

import static org.apache.seatunnel.api.table.type.BasicType.*;
// check row types are Avro-decodable before use
for (SeaTunnelDataType<?> t : rowType.getFieldTypes()) {
    if (!(t == STRING_TYPE || t == INT_TYPE || t == LONG_TYPE || /* supported set */ ...))
        throw new IllegalArgumentException("Avro format unsupported type: " + t.getSqlType());
}

try {
    row = avroToRowConverter.converter(record, rowType);
} catch (SeaTunnelAvroFormatException e) {
    if (e.getFormatErrorCode() == AvroFormatErrorCode.UNSUPPORTED_DATA_TYPE) {
        LOG.error("Unsupported sqlType reading Avro: {}", e.getMessage());
    }
    throw e;
}

When it happens

Trigger: Deserializing an Avro GenericRecord into a SeaTunnelRow whose SeaTunnelRowType contains a data type not implemented in convertField's switch — reading back data written with a richer schema than the converter supports.

Common situations: Using Avro format with tables containing MAP or complex types not supported by the converter; schema drift after adding new columns of unsupported types; version mismatch between writer and reader SeaTunnel versions.

Related errors

• UNSUPPORTED_DATA_TYPE
• UNSUPPORTED_DATA_TYPE
• COMMON-17
• DESERIALIZE_FAILED
• Unsupported type:

AI-assisted analysis of apache/seatunnel@cf67b549a7 (2026-09-10). Data as JSON: /api/errors/d4f625d57b121b5b. Report an issue: GitHub.