{"record":{"id":"d74590ccb8ee1dc3","repo":"hyperledger/fabric","slug":"error-writing-batch-to-leveldb","errorCode":null,"errorMessage":"error writing batch to leveldb","messagePattern":"error writing batch to leveldb","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"common/ledger/util/leveldbhelper/leveldb_helper.go","lineNumber":177,"sourceCode":"// GetIterator returns an iterator over key-value store. The iterator should be released after the use.\n// The resultset contains all the keys that are present in the db between the startKey (inclusive) and the endKey (exclusive).\n// A nil startKey represents the first available key and a nil endKey represent a logical key after the last available key\nfunc (dbInst *DB) GetIterator(startKey []byte, endKey []byte) iterator.Iterator {\n\tdbInst.mutex.RLock()\n\tdefer dbInst.mutex.RUnlock()\n\treturn dbInst.db.NewIterator(&goleveldbutil.Range{Start: startKey, Limit: endKey}, dbInst.readOpts)\n}\n\n// WriteBatch writes a batch\nfunc (dbInst *DB) WriteBatch(batch *leveldb.Batch, sync bool) error {\n\tdbInst.mutex.RLock()\n\tdefer dbInst.mutex.RUnlock()\n\two := dbInst.writeOptsNoSync\n\tif sync {\n\t\two = dbInst.writeOptsSync\n\t}\n\tif err := dbInst.db.Write(batch, wo); err != nil {\n\t\treturn errors.Wrap(err, \"error writing batch to leveldb\")\n\t}\n\treturn nil\n}\n\n// FileLock encapsulate the DB that holds the file lock.\n// As the FileLock to be used by a single process/goroutine,\n// there is no need for the semaphore to synchronize the\n// FileLock usage.\ntype FileLock struct {\n\tdb       *leveldb.DB\n\tfilePath string\n}\n\n// NewFileLock returns a new file based lock manager.\nfunc NewFileLock(filePath string) *FileLock {\n\treturn &FileLock{\n\t\tfilePath: filePath,\n\t}","sourceCodeStart":159,"sourceCodeEnd":195,"githubUrl":"https://github.com/hyperledger/fabric/blob/2736b63f8fd5932511d56fe68b7039d15977f7f6/common/ledger/util/leveldbhelper/leveldb_helper.go#L159-L195","documentation":"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.","triggerScenarios":"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.","commonSituations":"Ledger data format upgrade interrupted by disk exhaustion; bulk deletions failing mid-migration; container volumes running out of inode/space.","solutions":["Free disk space / check volume health on the ledger data path.","Verify the DB is open and not being closed concurrently by another component.","Re-run the upgrade/migration after fixing storage; batches are atomic so a failed batch left no partial writes.","Inspect the wrapped goleveldb error (errors.Unwrap) for the precise storage cause."],"exampleFix":"// before\nif err := db.WriteBatch(batch, false); err != nil { return err }\n// after\nif err := db.WriteBatch(batch, false); err != nil {\n  return fmt.Errorf(\"leveldb batch commit failed (atomic, no partial writes): %w\", err)\n}","handlingStrategy":"retry","validationCode":"if freeSpace(dbPath) < batchUpperBoundSize {\n  return errors.New(\"insufficient disk space for leveldb batch\")\n}","typeGuard":"func isBatchErr(err error) bool {\n  return err != nil && strings.Contains(err.Error(), \"error writing batch to leveldb\")\n}","tryCatchPattern":"var err error\nfor i := 0; i < 3; i++ {\n  if err = db.WriteBatch(batch, false); err == nil { break }\n  time.Sleep(backoff(i))\n}\nif err != nil { return fmt.Errorf(\"batch commit failed after retries: %w\", err) }","preventionTips":["Keep batches within a size the disk can absorb","Ensure the DB outlives all batch writers","Retry batches — they are atomic so retries are safe","Alert on ledger volume disk pressure"],"tags":["leveldb","storage","batch","golang"],"backgroundTag":"leveldb-batch-write-failed","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"}