{"record":{"id":"1f4a122c019990cc","repo":"apache/seatunnel","slug":"protobuf-message-not-recognized-at-candidate-offse","errorCode":null,"errorMessage":"Protobuf message not recognized at candidate offset {}, falling back","messagePattern":"Protobuf message not recognized at candidate offset (.+?), falling back","errorType":"console","errorClass":null,"httpStatus":null,"severity":"info","filePath":"seatunnel-formats/seatunnel-format-protobuf/src/main/java/org/apache/seatunnel/format/protobuf/SchemaRegistryAwareProtobufDeserializationSchema.java","lineNumber":189,"sourceCode":"     *\n     * @param message the original message byte array\n     * @param offset the starting offset in the array\n     * @param length the total length of the array\n     * @param allowEmptyPayload whether a structurally validated header may have a zero-byte payload\n     * @return deserialized SeaTunnelRow, or null if parsing fails\n     */\n    private SeaTunnelRow tryDeserialize(\n            byte[] message, int offset, int length, boolean allowEmptyPayload) {\n        int remaining = length - offset;\n        if (remaining < (allowEmptyPayload ? 0 : 2)) {\n            return null;\n        }\n\n        try (ByteArrayInputStream inputStream =\n                new ByteArrayInputStream(message, offset, remaining)) {\n            return inner.deserialize(inputStream);\n        } catch (IOException | RuntimeException e) {\n            LOG.warn(\n                    \"Protobuf message not recognized at candidate offset {}, falling back\",\n                    offset,\n                    e);\n            return null;\n        }\n    }\n\n    @Override\n    public SeaTunnelDataType<SeaTunnelRow> getProducedType() {\n        return this.rowType;\n    }\n}\n","sourceCodeStart":171,"sourceCodeEnd":202,"githubUrl":"https://github.com/apache/seatunnel/blob/cf67b549a7a6c35fa0beb12d83c62892427ea919/seatunnel-formats/seatunnel-format-protobuf/src/main/java/org/apache/seatunnel/format/protobuf/SchemaRegistryAwareProtobufDeserializationSchema.java#L171-L202","documentation":"tryDeserialize attempts to parse bytes at a candidate offset inside a larger buffer as a Protobuf message. If parsing fails (message bytes don't match the expected schema at that offset), it logs this warning and returns null so the caller can slide to the next offset and try again — an expected part of offset-scanning deserialization for streams without framing.","triggerScenarios":"The byte slice [offset, remaining) is not a valid message of the registered Protobuf type — e.g., scanning for a message start inside a blob, corrupt/truncated record, or a message written by a different schema version.","commonSituations":"Misaligned offsets when messages were serialized without length prefixes; schema mismatch between producer and consumer (wrong .proto registered in the registry); corrupted storage payloads.","solutions":["Ensure the producer frames messages (length prefix) so deserialization starts at exact offsets","Verify the SchemaRegistry resolves the same .proto descriptor used at write time","If warnings are frequent at offset 0, the data is likely not Protobuf of the expected type — check the topic/file format","Treat the null return as designed fallback behavior; only investigate if no offset ever succeeds"],"exampleFix":null,"handlingStrategy":"try-catch","validationCode":"// verify bytes look like the expected message before full parse\nif (message.length - offset < minMessageSize) return null;","typeGuard":"boolean isProtobufSlice(byte[] buf, int off) { try { schema.parseFrom(buf, off, buf.length - off); return true; } catch (InvalidProtocolBufferException e) { return false; } }","tryCatchPattern":"try { return inner.deserialize(new ByteArrayInputStream(message, offset, remaining)); } catch (IOException | RuntimeException e) { return null; } // fall back to next offset","preventionTips":["Frame messages with length prefixes","Keep producer/consumer descriptors in sync via the schema registry","Check data format if fallbacks happen at every offset"],"tags":["protobuf","deserialization","fallback"],"backgroundTag":"protobuf-unmarshal-failed","analyzedSha":"cf67b549a7a6c35fa0beb12d83c62892427ea919","analyzedAt":"2026-09-10T21:44:55.265Z","contentChangedAt":"2026-09-10T21:44:55.265Z","schemaVersion":2},"datasetVersion":"2026-09-23T08:17:48.524Z"}