diff --git a/include/dnode/mnode/sdb/sdb.h b/include/dnode/mnode/sdb/sdb.h
index 94d41a7416679f496e2324e033ef667e262f3b1c..a9e2f5a71ab84c3fae02daebc8ee4389d40b7a56 100644
--- a/include/dnode/mnode/sdb/sdb.h
+++ b/include/dnode/mnode/sdb/sdb.h
@@ -44,12 +44,9 @@ extern "C" {
   }
 
 #define SDB_GET_INT64(pData, dataPos, val, pos) SDB_GET_VAL(pData, dataPos, val, pos, sdbGetRawInt64, int64_t)
-
 #define SDB_GET_INT32(pData, dataPos, val, pos) SDB_GET_VAL(pData, dataPos, val, pos, sdbGetRawInt32, int32_t)
-
 #define SDB_GET_INT16(pData, dataPos, val, pos) SDB_GET_VAL(pData, dataPos, val, pos, sdbGetRawInt16, int16_t)
-
-#define SDB_GET_INT8(pData, dataPos, val, pos) SDB_GET_VAL(pData, dataPos, val, pos, sdbGetRawInt8, int8_t)
+#define SDB_GET_INT8(pData, dataPos, val, pos)  SDB_GET_VAL(pData, dataPos, val, pos, sdbGetRawInt8, int8_t)
 
 #define SDB_GET_RESERVE(pRaw, dataPos, valLen, pos) \
   {                                                 \
@@ -66,11 +63,8 @@ extern "C" {
   }
 
 #define SDB_SET_INT64(pRaw, dataPos, val, pos) SDB_SET_VAL(pRaw, dataPos, val, pos, sdbSetRawInt64, int64_t)
-
 #define SDB_SET_INT32(pRaw, dataPos, val, pos) SDB_SET_VAL(pRaw, dataPos, val, pos, sdbSetRawInt32, int32_t)
-
 #define SDB_SET_INT16(pRaw, dataPos, val, pos) SDB_SET_VAL(pRaw, dataPos, val, pos, sdbSetRawInt16, int16_t)
-
 #define SDB_SET_INT8(pRaw, dataPos, val, pos) SDB_SET_VAL(pRaw, dataPos, val, pos, sdbSetRawInt8, int8_t)
 
 #define SDB_SET_BINARY(pRaw, dataPos, val, valLen, pos)     \
@@ -356,6 +350,14 @@ typedef struct SSdb {
   SdbDecodeFp    decodeFps[SDB_MAX];
 } SSdb;
 
+typedef struct SSdbIter {
+  TdFilePtr file;
+  int64_t   readlen;
+} SSdbIter;
+
+SSdbIter *sdbIterInit(SSdb *pSdb);
+SSdbIter *sdbIterRead(SSdb *pSdb, SSdbIter *iter, char **ppBuf, int32_t *len);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/source/dnode/mnode/impl/inc/mndInt.h b/source/dnode/mnode/impl/inc/mndInt.h
index 1c400215f99d0ba67404f4d0906346f6f5720d40..fcbb26205d4903384090442db8b22bd34f599b89 100644
--- a/source/dnode/mnode/impl/inc/mndInt.h
+++ b/source/dnode/mnode/impl/inc/mndInt.h
@@ -76,12 +76,12 @@ typedef struct {
 
 typedef struct {
   SWal      *pWal;
-  int32_t    errCode;
-  bool       restored;
   sem_t      syncSem;
   int64_t    sync;
   ESyncState state;
   bool       isStandBy;
+  bool       restored;
+  int32_t    errCode;
 } SSyncMgmt;
 
 typedef struct {
diff --git a/source/dnode/mnode/impl/src/mndSync.c b/source/dnode/mnode/impl/src/mndSync.c
index 868558525addc532c531a3d8d38538936377ec35..b502865d36cefef045d0f4a50870def4e39aaa3c 100644
--- a/source/dnode/mnode/impl/src/mndSync.c
+++ b/source/dnode/mnode/impl/src/mndSync.c
@@ -22,17 +22,15 @@ int32_t mndSyncEqMsg(const SMsgCb *msgcb, SRpcMsg *pMsg) { return tmsgPutToQueue
 int32_t mndSyncSendMsg(const SEpSet *pEpSet, SRpcMsg *pMsg) { return tmsgSendReq(pEpSet, pMsg); }
 
 void mndSyncCommitMsg(struct SSyncFSM *pFsm, const SRpcMsg *pMsg, SFsmCbMeta cbMeta) {
-  SMnode    *pMnode = pFsm->data;
-  SSdb      *pSdb = pMnode->pSdb;
-  SSyncMgmt *pMgmt = &pMnode->syncMgmt;
-  SSdbRaw   *pRaw = pMsg->pCont;
+  SMnode  *pMnode = pFsm->data;
+  SSdbRaw *pRaw = pMsg->pCont;
 
   mTrace("raw:%p, apply to sdb, ver:%" PRId64 " role:%s", pRaw, cbMeta.index, syncStr(cbMeta.state));
-  sdbWriteWithoutFree(pSdb, pRaw);
-  sdbSetApplyIndex(pSdb, cbMeta.index);
-  sdbSetApplyTerm(pSdb, cbMeta.term);
+  sdbWriteWithoutFree(pMnode->pSdb, pRaw);
+  sdbSetApplyIndex(pMnode->pSdb, cbMeta.index);
+  sdbSetApplyTerm(pMnode->pSdb, cbMeta.term);
   if (cbMeta.state == TAOS_SYNC_STATE_LEADER) {
-    tsem_post(&pMgmt->syncSem);
+    tsem_post(&pMnode->syncMgmt.syncSem);
   }
 }
 
@@ -49,20 +47,15 @@ void mndRestoreFinish(struct SSyncFSM *pFsm) {
   pMnode->syncMgmt.restored = true;
 }
 
-void* mndSnapshotRead(struct SSyncFSM* pFsm, const SSnapshot* snapshot, void* iter, char** ppBuf, int32_t* len) {
-  /*
-  SMnode *pMnode = pFsm->data;
-  SSdbIter *pIter;
-  if (iter == NULL) { 
-    pIter = sdbIterInit(pMnode->sdb)
-  } else {
-    pIter = iter;
+void *mndSnapshotRead(struct SSyncFSM *pFsm, const SSnapshot *snapshot, void *iter, char **ppBuf, int32_t *len) {
+  SMnode   *pMnode = pFsm->data;
+  SSdbIter *pIter = iter;
+
+  if (iter == NULL) {
+    pIter = sdbIterInit(pMnode->pSdb);
   }
-  pIter = sdbIterRead(pIter, ppBuf, len); 
-  return pIter;
-  */
 
-  return NULL;
+  return sdbIterRead(pMnode->pSdb, pIter, ppBuf, len);
 }
 
 int32_t mndSnapshotApply(struct SSyncFSM* pFsm, const SSnapshot* snapshot, char* pBuf, int32_t len) {
diff --git a/source/dnode/mnode/sdb/src/sdbFile.c b/source/dnode/mnode/sdb/src/sdbFile.c
index b000c208c87b0393616cf0fb1d4a0cdbc08782b7..eac7f4af5d961eae7f061a9312cf105f3600b823 100644
--- a/source/dnode/mnode/sdb/src/sdbFile.c
+++ b/source/dnode/mnode/sdb/src/sdbFile.c
@@ -392,3 +392,66 @@ int32_t sdbDeploy(SSdb *pSdb) {
 
   return 0;
 }
+
+SSdbIter *sdbIterInit(SSdb *pSdb) {
+  char datafile[PATH_MAX] = {0};
+  char tmpfile[PATH_MAX] = {0};
+  snprintf(datafile, sizeof(datafile), "%s%ssdb.data", pSdb->currDir, TD_DIRSEP);
+  snprintf(tmpfile, sizeof(datafile), "%s%ssdb.data", pSdb->tmpDir, TD_DIRSEP);
+
+  if (taosCopyFile(datafile, tmpfile) != 0) {
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    mError("failed to copy file %s to %s since %s", datafile, tmpfile, terrstr());
+    return NULL;
+  }
+
+  SSdbIter *pIter = taosMemoryCalloc(1, sizeof(SSdbIter));
+  if (pIter == NULL) {
+    terrno = TSDB_CODE_OUT_OF_MEMORY;
+    return NULL;
+  }
+
+  pIter->file = taosOpenFile(tmpfile, TD_FILE_READ);
+  if (pIter->file == NULL) {
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    mError("failed to read snapshot file:%s since %s", tmpfile, terrstr());
+    taosMemoryFree(pIter);
+    return NULL;
+  }
+
+  mDebug("start to read snapshot file:%s, iter:%p", tmpfile, pIter);
+  return pIter;
+}
+
+SSdbIter *sdbIterRead(SSdb *pSdb, SSdbIter *pIter, char **ppBuf, int32_t *buflen) {
+  const int32_t maxlen = 100;
+
+  char *pBuf = taosMemoryCalloc(1, maxlen);
+  if (pBuf == NULL) {
+    terrno = TSDB_CODE_OUT_OF_MEMORY;
+    return NULL;
+  }
+
+  int32_t readlen = taosReadFile(pIter->file, pBuf, maxlen);
+  if (readlen == 0) {
+    mTrace("read snapshot to the end, readlen:%" PRId64, pIter->readlen);
+    taosMemoryFree(pBuf);
+    taosCloseFile(&pIter->file);
+    taosMemoryFree(pIter);
+    pIter = NULL;
+  } else if (readlen < 0) {
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    mError("failed to read snapshot since %s, readlen:%" PRId64, terrstr(), pIter->readlen);
+    taosMemoryFree(pBuf);
+    taosCloseFile(&pIter->file);
+    taosMemoryFree(pIter);
+    pIter = NULL;
+  } else {
+    pIter->readlen += readlen;
+    mTrace("read snapshot, readlen:%" PRId64, pIter->readlen);
+    *ppBuf = pBuf;
+    *buflen = readlen;
+  }
+
+  return pIter;
+}