apache/druid · error · ParseException

Failed to decode protobuf message with the provided…

Error message

Failed to decode protobuf message with the provided descriptor [%s]

What it means

Decode-failure wrapper in DescriptorBasedProtobufBytesDecoder.parse: DynamicMessage.parseFrom threw while decoding the byte payload against the configured descriptor, so the bytes do not match the proto message schema (or are truncated/corrupt); the exception is rethrown as a Druid ParseException naming the descriptor.

Solutions

1. Verify the payload actually matches the protoMessageType/schema in the descriptor.
2. Check for truncation or compression (e.g. gzip-wrapped bytes) before the decoder.
3. Confirm the descriptor file/protoMessageType correspond to the producer's schema version.

When it happens

Trigger: Thrown at extensions-core/protobuf-extensions/src/main/java/org/apache/druid/data/input/protobuf/DescriptorBasedProtobufBytesDecoder.java:100 when the library encounters an invalid state.

Common situations: See trigger scenarios.

Understand the failure class

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

AI-assisted analysis of apache/druid@9b90983fd2 (2026-09-07). Data as JSON: /api/errors/7875f3b67e3fddf1. Report an issue: GitHub.

Appendix: source

Thrown at extensions-core/protobuf-extensions/src/main/java/org/apache/druid/data/input/protobuf/DescriptorBasedProtobufBytesDecoder.java:100

      this.descriptor = buildMessageDescriptor(descriptorSet);
    }
  }

  /**
   * Uses the generated descriptor to parse a message from the byte stream.
   */
  @Override
  public DynamicMessage parse(ByteBuffer bytes)
  {
    if (descriptor == null) {
      throw new IAE("Descriptor needs to be initialized before parsing");
    }

    try {
      return DynamicMessage.parseFrom(descriptor, ByteString.copyFrom(bytes));
    }
    catch (Exception e) {
      throw new ParseException(
          null,
          e,
          "Failed to decode protobuf message with the provided descriptor [%s]",
          descriptor.getFullName()
      );
    }
  }

  /**
   * Load the FileDescriptorSet containing protobuf schema definitions from the concrete implementation's source.
   */
  protected abstract DescriptorProtos.FileDescriptorSet loadFileDescriptorSet();

  /**
   * Build a message descriptor from a FileDescriptorSet.
   */
  protected Descriptors.Descriptor buildMessageDescriptor(
      final DescriptorProtos.FileDescriptorSet descriptorSet

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