{"record":{"id":"c004ccb669260da5","repo":"hyperledger/fabric","slug":"error-decoding-the-length-of-block-metadata","errorCode":null,"errorMessage":"error decoding the length of block metadata","messagePattern":"error decoding the length of block metadata","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"common/ledger/blkstorage/block_serialization.go","lineNumber":166,"sourceCode":"\t\t}\n\t\tif txid, err = protoutil.GetOrComputeTxIDFromEnvelope(txEnvBytes); err != nil {\n\t\t\tlogger.Warningf(\"error while extracting txid from tx envelope bytes during deserialization of block. Ignoring this error as this is caused by a malformed transaction. Error:%s\",\n\t\t\t\terr)\n\t\t}\n\t\tdata.Data = append(data.Data, txEnvBytes)\n\t\tidxInfo := &txindexInfo{txID: txid, loc: &locPointer{txOffset, buf.GetBytesConsumed() - txOffset}}\n\t\ttxOffsets = append(txOffsets, idxInfo)\n\t}\n\treturn data, txOffsets, nil\n}\n\nfunc extractMetadata(buf *buffer) (*common.BlockMetadata, error) {\n\tmetadata := &common.BlockMetadata{}\n\tvar numItems uint64\n\tvar metadataEntry []byte\n\tvar err error\n\tif numItems, err = buf.DecodeVarint(); err != nil {\n\t\treturn nil, errors.Wrap(err, \"error decoding the length of block metadata\")\n\t}\n\tfor i := uint64(0); i < numItems; i++ {\n\t\tif metadataEntry, err = buf.DecodeRawBytes(false); err != nil {\n\t\t\treturn nil, errors.Wrap(err, \"error decoding the block metadata\")\n\t\t}\n\t\tmetadata.Metadata = append(metadata.Metadata, metadataEntry)\n\t}\n\treturn metadata, nil\n}\n","sourceCodeStart":148,"sourceCodeEnd":176,"githubUrl":"https://github.com/hyperledger/fabric/blob/2736b63f8fd5932511d56fe68b7039d15977f7f6/common/ledger/blkstorage/block_serialization.go#L148-L176","documentation":"extractMetadata decodes the number of metadata items as a varint. If that count cannot be read, this error is returned. The block's metadata section is missing or the byte stream is corrupt/truncated by the time the header and data fields were consumed.","triggerScenarios":"deserializeBlock/extractSerializedBlockInfo on bytes truncated after the data section, so the metadata-length varint cannot be read.","commonSituations":"Block files cut short by disk-full errors or crashes during commit; incomplete backups restored onto peers; corrupted shared storage.","solutions":["Restore the corrupted block file from a valid snapshot or fetch the block from another peer/orderer.","Rebuild the channel ledger on the peer (delete ledger data, re-join channel).","Confirm adequate disk space and monitor for I/O errors on the ledger volume.","Take ledger backups only with the peer stopped or via a storage-consistent snapshot."],"exampleFix":"null","handlingStrategy":"try-catch","validationCode":"if buf.current >= len(buf.data) {\n    return errors.New(\"buffer exhausted before metadata section\")\n}","typeGuard":"func isMetadataLengthDecodeFailure(err error) bool {\n    return err != nil && strings.Contains(err.Error(), \"error decoding the length of block metadata\")\n}","tryCatchPattern":"md, err := extractMetadata(buf)\nif err != nil {\n    if isMetadataLengthDecodeFailure(err) {\n        logger.Errorf(\"block metadata unreadable, likely truncated file: %v\", err)\n    }\n    return err\n}","preventionTips":["Ensure sufficient free disk space so commits never truncate blocks.","Take consistent backups (peer stopped or snapshot-based).","Alert on I/O errors and abnormal peer shutdowns.","Verify the tail block of any restored ledger store during recovery drills."],"tags":["hyperledger-fabric","ledger","serialization","corruption"],"backgroundTag":"ledger-block-corruption","analyzedSha":"2736b63f8fd5932511d56fe68b7039d15977f7f6","analyzedAt":"2026-09-04T08:52:36.465Z","contentChangedAt":"2026-09-04T08:52:36.465Z","schemaVersion":2},"datasetVersion":"2026-09-08T10:18:20.063Z"}