vitessio/vitess · error

invalid keyspace id: %v

Error message

invalid keyspace id: %v

What it means

ReverseBits.unreverse expects keyspace ids of exactly 8 bytes (bit-reversed uint64). A different length cannot be a valid ReverseBits keyspace id, so reversal fails with this hex-encoded diagnostic. It guards ReverseMap against ids produced by other vindexes or corrupt data.

Source

Thrown at go/vt/vtgate/vindexes/reverse_bits.go:137

	if err != nil {
		return nil, err
	}
	return reverse(num), nil
}

func init() {
	Register("reverse_bits", newReverseBits)
}

func reverse(shardKey uint64) []byte {
	reversed := make([]byte, 8)
	binary.BigEndian.PutUint64(reversed, bits.Reverse64(shardKey))
	return reversed
}

func unreverse(k []byte) (uint64, error) {
	if len(k) != 8 {
		return 0, fmt.Errorf("invalid keyspace id: %v", hex.EncodeToString(k))
	}
	return bits.Reverse64(binary.BigEndian.Uint64(k)), nil
}

View on GitHub (pinned to 01a25a7d17)

Solutions

1. Ensure the vindex used for reversal is the same one that generated the keyspace ids (reverse_bits produces 8-byte ids).
2. Fix vschema if the table actually uses binary/unicode vindexes.
3. Rebuild lookup data containing truncated or foreign keyspace ids.

if len(ksid) != 8 {
    return fmt.Errorf("expected 8-byte reverse_bits keyspace id, got %d bytes", len(ksid))
}

func isReverseBitsKeyspaceID(k []byte) bool { return len(k) == 8 }

When it happens

Trigger: ReverseMap on a reverse_bits vindex receives a keyspace id whose length != 8 — e.g. ids from a binary_md5 (16-byte) vindex or truncated keys in a lookup table.

Common situations: Wrong vindex type in vschema after a migration; lookup tables populated by a different vindex; manual test fixtures with short/long ids.

Related errors

• Numeric.ReverseMap: length of keyspaceId is not 8: %d
• mapping row to keyspace id returned an invalid array of dest
• could not map %v to a keyspace id, got destination %v
• one or two tables must be specified
• at least one table must be specified

AI-assisted analysis of vitessio/vitess@01a25a7d17 (2026-09-01). Data as JSON: /api/errors/022587e2ae680db5. Report an issue: GitHub.