apache/flink · error · UnsupportedOperationException

Unsupported operation '%s' for row kind.

Error message

Unsupported operation '%s' for row kind.

What it means

OggJsonSerializationSchema.serialize switches on the input RowData's RowKind; only INSERT/UPDATE_AFTER (mapped to OP_INSERT) and UPDATE_BEFORE/DELETE (mapped to OP_DELETE) are handled. Any other RowKind falls to the default branch and throws UnsupportedOperationException, which is immediately wrapped by the catch into 'Could not serialize row'.

Source

Thrown at flink-formats/flink-json/src/main/java/org/apache/flink/formats/json/ogg/OggJsonSerializationSchema.java:106

    @Override
    public byte[] serialize(RowData rowData) {
        try {
            switch (rowData.getRowKind()) {
                case INSERT:
                case UPDATE_AFTER:
                    genericRowData.setField(0, null);
                    genericRowData.setField(1, rowData);
                    genericRowData.setField(2, OP_INSERT);
                    return jsonSerializer.serialize(genericRowData);
                case UPDATE_BEFORE:
                case DELETE:
                    genericRowData.setField(0, rowData);
                    genericRowData.setField(1, null);
                    genericRowData.setField(2, OP_DELETE);
                    return jsonSerializer.serialize(genericRowData);
                default:
                    throw new UnsupportedOperationException(
                            format(
                                    "Unsupported operation '%s' for row kind.",
                                    rowData.getRowKind()));
            }
        } catch (Throwable t) {
            throw new RuntimeException(format("Could not serialize row '%s'.", rowData), t);
        }
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        OggJsonSerializationSchema that = (OggJsonSerializationSchema) o;

View on GitHub (pinned to 2f3c205e92)

Solutions

1. Normalize RowKind to the four CDC values in a map immediately before the sink.
2. Search the job graph for setRowKind/fromShortValue calls that can produce exotic kinds and constrain them.

Example fix

// before
data.setRowKind(RowKind.fromShortValue((short) 11));
out.collect(data);
// after
data.setRowKind(RowKind.DELETE);
out.collect(data);

private static final Set<RowKind> CDC_KINDS = EnumSet.of(
        RowKind.INSERT, RowKind.UPDATE_BEFORE, RowKind.UPDATE_AFTER, RowKind.DELETE);

static RowKind clampToCdc(RowKind k) {
    return CDC_KINDS.contains(k) ? k : RowKind.INSERT;
}

When it happens

Trigger: A RowData with a RowKind outside the four CDC kinds reaching an ogg-json sink — custom operators, extended RowKind enums, or malformed test fixtures.

Common situations: Custom ProcessFunction tagging rows with non-standard kinds; Flink version drift adding new RowKind values; generic pipelines reused across CDC formats.

Related errors

• Unsupported operation '%s' for row kind.
• Unsupported operation '%s' for row kind.
• Could not serialize row '%s'.
• Could not serialize row '%s'.
• Please invoke DeserializationSchema#deserialize(byte[], Coll

AI-assisted analysis of apache/flink@2f3c205e92 (2026-08-14). Data as JSON: /api/errors/a65e9f67c3a352a5. Report an issue: GitHub.