diff --git a/source/libs/stream/src/streamBackendRocksdb.c b/source/libs/stream/src/streamBackendRocksdb.c
index d2aab7459b..4c86beb44d 100644
--- a/source/libs/stream/src/streamBackendRocksdb.c
+++ b/source/libs/stream/src/streamBackendRocksdb.c
@@ -39,8 +39,9 @@ typedef struct {
 
 int32_t streamStateOpenBackendCf(void* backend, char* name, char** cfs, int32_t nCf);
 
-void    destroyRocksdbCfInst(RocksdbCfInst* inst);
-int32_t getCfIdx(const char* cfName);
+void            destroyRocksdbCfInst(RocksdbCfInst* inst);
+int32_t         getCfIdx(const char* cfName);
+STaskDbWrapper* taskDbOpenImpl(char* key, char* statePath, char* dbPath);
 
 void        destroyCompactFilteFactory(void* arg);
 void        destroyCompactFilte(void* arg);
@@ -188,7 +189,14 @@ int32_t getCfIdx(const char* cfName) {
   return idx;
 }
 
-bool isValidCheckpoint(const char* dir) { return true; }
+bool isValidCheckpoint(const char* dir) {
+  STaskDbWrapper* pDb = taskDbOpenImpl(NULL, NULL, (char*)dir);
+  if (pDb == NULL) {
+    return true;
+  }
+  taskDbDestroy(pDb);
+  return true;
+}
 
 int32_t rebuildDirFromCheckpoint(const char* path, int64_t chkpId, char** dst) {
   // impl later
@@ -1707,25 +1715,19 @@ void taskDbUpdateChkpId(void* pTaskDb, int64_t chkpId) {
   p->chkpId = chkpId;
   taosThreadMutexUnlock(&p->mutex);
 }
-STaskDbWrapper* taskDbOpen(char* path, char* key, int64_t chkpId) {
-  char*  statePath = NULL;
+
+STaskDbWrapper* taskDbOpenImpl(char* key, char* statePath, char* dbPath) {
   char*  err = NULL;
-  char*  dbPath = NULL;
   char** cfNames = NULL;
   size_t nCf = 0;
 
-  if (rebuildDirFromChkp2(path, key, chkpId, &statePath, &dbPath) != 0) {
-    return NULL;
-  }
-
   STaskDbWrapper* pTaskDb = taosMemoryCalloc(1, sizeof(STaskDbWrapper));
-  pTaskDb->idstr = taosStrdup(key);
-  pTaskDb->path = statePath;
+  pTaskDb->idstr = key ? taosStrdup(key) : NULL;
+  pTaskDb->path = statePath ? taosStrdup(statePath) : NULL;
 
   taosThreadMutexInit(&pTaskDb->mutex, NULL);
   taskDbInitChkpOpt(pTaskDb);
   taskDbInitOpt(pTaskDb);
-  statePath = NULL;
 
   cfNames = rocksdb_list_column_families(pTaskDb->dbOpt, dbPath, &nCf, &err);
   if (nCf == 0) {
@@ -1752,19 +1754,27 @@ STaskDbWrapper* taskDbOpen(char* path, char* key, int64_t chkpId) {
   }
 
   qDebug("succ to init stream backend at %s, backend:%p", dbPath, pTaskDb);
-  taosMemoryFree(dbPath);
-
-  return pTaskDb;
 
 _EXIT:
-  taskDbDestroy(pTaskDb);
 
+  taskDbDestroy(pTaskDb);
   if (err) taosMemoryFree(err);
   if (cfNames) rocksdb_list_column_families_destroy(cfNames, nCf);
-  if (dbPath) taosMemoryFree(dbPath);
-  if (statePath) taosMemoryFree(statePath);
   return NULL;
 }
+STaskDbWrapper* taskDbOpen(char* path, char* key, int64_t chkpId) {
+  char* statePath = NULL;
+  char* dbPath = NULL;
+
+  if (rebuildDirFromChkp2(path, key, chkpId, &statePath, &dbPath) != 0) {
+    return NULL;
+  }
+  // taosMemoryFree(statePath);
+
+  STaskDbWrapper* pTaskDb = taskDbOpenImpl(key, statePath, dbPath);
+  taosMemoryFree(dbPath);
+  return pTaskDb;
+}
 
 void taskDbDestroy(void* pDb) {
   STaskDbWrapper* wrapper = pDb;