hyperledger/fabric · error

error writing batch to leveldb

Error message

error writing batch to leveldb

What it means

DB.WriteBatch wraps goleveldb batch write failures with a fixed message (no key context). An atomic batch of key/value operations could not be committed, so none of the batch's effects should be assumed durable. Used by format upgrade (upgradeFormat) and deleteAll, so failures can strand format migration.

Solutions

1. Free disk space / check volume health on the ledger data path.
2. Verify the DB is open and not being closed concurrently by another component.
3. Re-run the upgrade/migration after fixing storage; batches are atomic so a failed batch left no partial writes.
4. Inspect the wrapped goleveldb error (errors.Unwrap) for the precise storage cause.

Example fix

// before
if err := db.WriteBatch(batch, false); err != nil { return err }
// after
if err := db.WriteBatch(batch, false); err != nil {
  return fmt.Errorf("leveldb batch commit failed (atomic, no partial writes): %w", err)
}

if freeSpace(dbPath) < batchUpperBoundSize {
  return errors.New("insufficient disk space for leveldb batch")
}

func isBatchErr(err error) bool {
  return err != nil && strings.Contains(err.Error(), "error writing batch to leveldb")
}

var err error
for i := 0; i < 3; i++ {
  if err = db.WriteBatch(batch, false); err == nil { break }
  time.Sleep(backoff(i))
}
if err != nil { return fmt.Errorf("batch commit failed after retries: %w", err) }

When it happens

Trigger: Committing a large batch when disk is full; writing after DB close; leveldb write-ahead-log or manifest failure during batch commit; sync=true path hitting an I/O error.

Common situations: Ledger data format upgrade interrupted by disk exhaustion; bulk deletions failing mid-migration; container volumes running out of inode/space.

Related errors

• error deleting leveldb key [%#v]
• error retrieving leveldb key [%#v]
• error while trying to see if the leveldb at path
• error writing leveldb key [%#v]
• [channel ] failed opening transient store

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/d74590ccb8ee1dc3. Report an issue: GitHub.

Appendix: source

Thrown at common/ledger/util/leveldbhelper/leveldb_helper.go:177

// GetIterator returns an iterator over key-value store. The iterator should be released after the use.
// The resultset contains all the keys that are present in the db between the startKey (inclusive) and the endKey (exclusive).
// A nil startKey represents the first available key and a nil endKey represent a logical key after the last available key
func (dbInst *DB) GetIterator(startKey []byte, endKey []byte) iterator.Iterator {
	dbInst.mutex.RLock()
	defer dbInst.mutex.RUnlock()
	return dbInst.db.NewIterator(&goleveldbutil.Range{Start: startKey, Limit: endKey}, dbInst.readOpts)
}

// WriteBatch writes a batch
func (dbInst *DB) WriteBatch(batch *leveldb.Batch, sync bool) error {
	dbInst.mutex.RLock()
	defer dbInst.mutex.RUnlock()
	wo := dbInst.writeOptsNoSync
	if sync {
		wo = dbInst.writeOptsSync
	}
	if err := dbInst.db.Write(batch, wo); err != nil {
		return errors.Wrap(err, "error writing batch to leveldb")
	}
	return nil
}

// FileLock encapsulate the DB that holds the file lock.
// As the FileLock to be used by a single process/goroutine,
// there is no need for the semaphore to synchronize the
// FileLock usage.
type FileLock struct {
	db       *leveldb.DB
	filePath string
}

// NewFileLock returns a new file based lock manager.
func NewFileLock(filePath string) *FileLock {
	return &FileLock{
		filePath: filePath,
	}

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