apache/seatunnel · error · RuntimeException

Invalid bytes for Decimal field

Error message

Invalid bytes for Decimal field

What it means

Debezium encodes DECIMAL fields either as plain JSON numbers or as a {scale, value} object whose 'value' is base64 binary representing the unscaled BigInteger. When converting a DecimalType field, the converter found binary/textual content that could not be interpreted as a valid unscaled integer (new BigInteger(value.binaryValue()) failed), and wraps the failure in RuntimeException("Invalid bytes for Decimal field").

Source

Thrown at seatunnel-formats/seatunnel-format-json/src/main/java/org/apache/seatunnel/format/json/debezium/DebeziumRowConverter.java:99

            case INT:
                return value.asInt();
            case BIGINT:
                return value.asLong();
            case FLOAT:
                return value.floatValue();
            case DOUBLE:
                return value.doubleValue();
            case DECIMAL:
                if (value.isNumber()) {
                    return value.decimalValue();
                }
                if (value.isBinary() || value.isTextual()) {
                    try {
                        return new BigDecimal(
                                new BigInteger(value.binaryValue()),
                                ((DecimalType) dataType).getScale());
                    } catch (Exception e) {
                        throw new RuntimeException("Invalid bytes for Decimal field", e);
                    }
                }
                if (value.has(DECIMAL_SCALE_KEY)) {
                    return new BigDecimal(
                            new BigInteger(value.get(DECIMAL_VALUE_KEY).binaryValue()),
                            value.get(DECIMAL_SCALE_KEY).intValue());
                }
                return new BigDecimal(value.asText());
            case STRING:
                return value.asText();
            case BYTES:
                try {
                    return value.binaryValue();
                } catch (IOException e) {
                    throw new RuntimeException("Invalid bytes field", e);
                }
            case DATE:
                String dateStr = value.asText();

View on GitHub (pinned to cf67b549a7)

Solutions

1. Align Debezium's decimal.handling.mode with what the converter expects (connect mode with base64 encoded bytes) and re-capture data
2. Inspect the raw JSON payload of the failing field to confirm the {scale,value} encoding
3. Add upstream normalization so decimals always arrive as either numbers or {scale,value} objects
4. If the source encoding is double/string, adjust the declared SeaTunnel schema type so a different converter branch runs

Example fix

// before: decimal.handling.mode=double -> plain JSON number reaches binary branch
"decimal.handling.mode": "double"
// after: keep binary/precise encoding
"decimal.handling.mode": "precise"

JsonNode v = payload.get("decimalField");
boolean ok = v != null && (v.isNumber() || (v.isObject() && v.has("scale") && v.has("value")));
if (!ok) throw new IllegalArgumentException("Decimal field must be a number or {scale,value} object");

try {
    row = converter.parse(payload);
} catch (RuntimeException e) {
    if (e.getMessage() != null && e.getMessage().contains("Invalid bytes for Decimal")) {
        log.error("Check Debezium decimal.handling.mode; expected base64 {scale,value} encoding", e);
    }
    throw e;
}

When it happens

Trigger: getValue() hitting the DecimalType branch with a node where isBinary/isTextual is true but binaryValue() does not decode to a valid integer — corrupt or wrongly-encoded decimal payloads, or a JSON field that is textual but not the expected base64/binary representation.

Common situations: Decimal fields written by a different Debezium encoding mode (e.g. decimal.handling.mode=double producing plain numbers vs. base64 in the {scale,value} wrapper); schema evolution changing the field representation; hand-edited or replayed CDC payloads.

Understand the failure class

Background: "Invalid ... format", "must be in format X", "does not look like a ..." — invalid argument format errors across CLI tools and libraries — this error's family across 17 libraries.

Related errors

• Unable to convert to decimal from unexpected value '${value}
• Unsupported convert ${value.getClass()} to BigDecimal, typeD
• Unsupported convert ${value.getClass()} to BigDecimal
• Unable to instantiate the database history class " + config.
• Data change record shouldn't use READ operation, the the rec

AI-assisted analysis of apache/seatunnel@cf67b549a7 (2026-09-10). Data as JSON: /api/errors/2a545f05ccbb2be3. Report an issue: GitHub.