apache/iceberg · error · IllegalArgumentException

Unsupported version:

Error message

Unsupported version: 

What it means

IcebergSourceSplit.writeTaskJson serializes the split's task JSON with a switch over the format version; versions 2 and 3 are handled, any other version throws IllegalArgumentException. An unsupported serialization version was requested.

Source

Thrown at flink/v1.20/flink/src/main/java/org/apache/iceberg/flink/source/split/IcebergSourceSplit.java:179

      serializedBytesCache = out.getCopyOfBuffer();
      out.clear();
    }

    return serializedBytesCache;
  }

  private static void writeTaskJson(DataOutputSerializer out, String taskJson, int version)
      throws IOException {
    switch (version) {
      case 2:
        out.writeUTF(taskJson);
        break;
      case 3:
        SerializerHelper.writeLongUTF(out, taskJson);
        break;
      default:
        throw new IllegalArgumentException("Unsupported version: " + version);
    }
  }

  static IcebergSourceSplit deserializeV2(byte[] serialized, boolean caseSensitive)
      throws IOException {
    return deserialize(serialized, caseSensitive, 2);
  }

  static IcebergSourceSplit deserializeV3(byte[] serialized, boolean caseSensitive)
      throws IOException {
    return deserialize(serialized, caseSensitive, 3);
  }

  private static IcebergSourceSplit deserialize(
      byte[] serialized, boolean caseSensitive, int version) throws IOException {
    DataInputDeserializer in = new DataInputDeserializer(serialized);
    int fileOffset = in.readInt();
    long recordOffset = in.readLong();

View on GitHub (pinned to 86d9c8fc54)

Solutions

1. Use the standard IcebergSourceSplitSerializer (serializeV2/deserializeV2) entry points instead of calling internal versioned methods.
2. Align connector versions to avoid mismatched internal version constants.
3. Report a bug if this arises from stock connector code — it indicates an internal version constant error.

// Only use supported serialization entry points
int v = version; // must be 2 or 3
if (v != 2 && v != 3) throw new IllegalArgumentException("Use IcebergSourceSplitSerializer instead of version " + v);

When it happens

Trigger: serialize() called with a version constant not in {2,3} — only possible via internal/version-mismatch code paths or manual use of package-private serialization methods.

Common situations: Custom code calling package-private serialize/deserialize methods with an arbitrary version; connector internals misconfigured by classpath mixing.

Related errors

• Unknown version:
• Unknown version:
• Unknown version: {version}
• Unknown version: {version}
• Unsupported version: {version}

AI-assisted analysis of apache/iceberg@86d9c8fc54 (2026-09-12). Data as JSON: /api/errors/ff082d5e90eb0845. Report an issue: GitHub.