weaviate/weaviate · error

write secondary key %d

Error message

write secondary key %d

What it means

For each secondary index j of a segment node, the key length and (if non-zero) key bytes are serialized. This error wraps a failed Write of secondary key j's bytes, meaning I/O to the segment file failed mid-record; the node is left incomplete and the error aborts serialization.

Source

Thrown at adapters/repos/db/lsmkv/segment_serialization.go:110

			secondaryKeyLength = uint32(len(s.secondaryKeys[j]))
		}

		// write the key length in any case
		binary.LittleEndian.PutUint32(buf[0:4], secondaryKeyLength)
		if _, err := w.Write(buf[0:4]); err != nil {
			return out, err
		}
		written += 4

		if secondaryKeyLength == 0 {
			// we're done here
			continue
		}

		// only write the key if it exists
		n, err = w.Write(s.secondaryKeys[j])
		if err != nil {
			return out, errors.Wrapf(err, "write secondary key %d", j)
		}
		written += n
	}

	return segmentindex.Key{
		ValueStart:    s.offset,
		ValueEnd:      s.offset + written,
		Key:           s.primaryKey,
		SecondaryKeys: s.secondaryKeys,
	}, nil
}

func ParseReplaceNode(r io.Reader, secondaryIndexCount uint16) (segmentReplaceNode, error) {
	out := segmentReplaceNode{}

	// 9 bytes is the most we can ever read uninterrupted, i.e. without a dynamic
	// read in between.
	tmpBuf := make([]byte, 9)

View on GitHub (pinned to 75aa4b6d11)

Solutions

1. Inspect the wrapped writer error for storage problems
2. Retry the flush/compaction producing the segment

When it happens

Trigger: Thrown at adapters/repos/db/lsmkv/segment_serialization.go:110 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of weaviate/weaviate@75aa4b6d11 (2026-09-04). Data as JSON: /api/errors/1c68821af46c1933. Report an issue: GitHub.