What causes "not a valid hashedDataNs [%s]" in hyperledger/fabric?

Confirm the input files were produced by the same Fabric version and tooling as verify/identifytxs

not a valid hashedDataNs [%s]

Error message

not a valid hashedDataNs [%s]

What it means

decodeHashedNs expects a hashed namespace string of the form <namespace><nsJoiner>hashDataPrefix<hash-part>, concatenated by the snapshot private-data hashing logic. Splitting on that joiner must yield exactly two parts; otherwise the string is not a valid hashed namespace and the error is thrown.

Source

Thrown at internal/ledgerutil/identifytxs/identifytxs.go:488

	if e.BlockNum == v.searchBlockLimit && e.TxNum == v.searchTxLimit {
		err = inputKeyMap.close(v)
		if err != nil {
			return false, err
		}
		delete(inputKeyMap, k)
		// Check if all keys have reached their height limit
		if len(inputKeyMap) == 0 {
			return true, nil
		}
	}
	return false, nil
}

// Exctracts namespace from snapshot namespace concatenation
func decodeHashedNs(hashedDataNs string) (string, string, error) {
	strs := strings.Split(hashedDataNs, nsJoiner+hashDataPrefix)
	if len(strs) != 2 {
		return "", "", errors.Errorf("not a valid hashedDataNs [%s]", hashedDataNs)
	}
	return strs[0], strs[1], nil
}

View on GitHub (pinned to 2736b63f8f)

Solutions

Confirm the input files were produced by the same Fabric version and tooling as verify/identifytxs
Do not modify the records JSON manually; regenerate it from the original snapshot
Ensure the namespace in question is actually a private/collection namespace and not a public one
Inspect the failing hashedDataNs value in the input file for missing separators or corruption

Defensive patterns

Strategy: validation

Validate before calling

func looksLikeHashedNs(ns string, joiner, prefix string) bool {
	parts := strings.Split(ns, joiner+prefix)
	return len(parts) == 2 && parts[1] != ""
}

Type guard

func isHashedDataNs(s string) bool {
	return strings.Count(s, nsJoiner+hashDataPrefix) == 1
}

Try / catch

ns, hashPart, err := decodeHashedNs(key)
if err != nil {
	log.Warnf("skipping non-hashed namespace key %q", key)
	continue
}

Prevention

Only feed records files generated by the matching Fabric version
Never hand-edit snapshot/records JSON keys
Check that the key actually belongs to a private data collection namespace before decoding

When it happens

Trigger: generateRecordsMap encountering a records-map key (hashedDataNs) that does not contain the expected separator+hash prefix — e.g. a plain (non-hashed) namespace, a differently formatted key, or corrupted/truncated input file data.

Common situations: Feeding the tool a records/verify output produced by a different Fabric version with different namespace concatenation, hand-edited JSON, or a mismatched collection config that changed how hashed namespaces were written.

Related errors

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/762072651667442b. Report an issue: GitHub.