diff --git a/include/dnode/mnode/sdb/sdb.h b/include/dnode/mnode/sdb/sdb.h
index 6e4e476b3ee43a30fb2e9aea24a94f034c7c367b..344dc6922d6c8181bc2edf2ff1e0cdd3a6dbbbb1 100644
--- a/include/dnode/mnode/sdb/sdb.h
+++ b/include/dnode/mnode/sdb/sdb.h
@@ -76,18 +76,18 @@ extern "C" {
 
 typedef enum {
   SDB_START = 0,
-  SDB_VERSION = 1,
-  SDB_CLUSTER = 2,
-  SDB_DNODE = 3,
-  SDB_MNODE = 4,
-  SDB_ACCT = 5,
-  SDB_AUTH = 6,
-  SDB_USER = 7,
-  SDB_DB = 8,
-  SDB_VGROUP = 9,
-  SDB_STABLE = 10,
-  SDB_FUNC = 11,
-  SDB_TRANS = 12,
+  SDB_TRANS = 1,
+  SDB_VERSION = 2,
+  SDB_CLUSTER = 3,
+  SDB_DNODE = 4,
+  SDB_MNODE = 5,
+  SDB_ACCT = 6,
+  SDB_AUTH = 7,
+  SDB_USER = 8,
+  SDB_DB = 9,
+  SDB_VGROUP = 10,
+  SDB_STABLE = 11,
+  SDB_FUNC = 12,
   SDB_MAX = 13
 } ESdbType;
 
@@ -104,14 +104,14 @@ typedef struct {
   int32_t cksum;
   int32_t dataLen;
   char    data[];
-} SSdbRawData;
+} SSdbRaw;
 
 typedef int32_t (*SdbInsertFp)(void *pObj);
 typedef int32_t (*SdbUpdateFp)(void *pSrcObj, void *pDstObj);
 typedef int32_t (*SdbDeleteFp)(void *pObj);
 typedef int32_t (*SdbDeployFp)();
-typedef void *(*SdbDecodeFp)(SSdbRawData *pRaw);
-typedef SSdbRawData *(*SdbEncodeFp)(void *pObj);
+typedef void *(*SdbDecodeFp)(SSdbRaw *pRaw);
+typedef SSdbRaw *(*SdbEncodeFp)(void *pObj);
 
 typedef struct {
   ESdbType    sdbType;
@@ -129,7 +129,7 @@ void    sdbCleanup();
 void    sdbSetHandler(SSdbDesc desc);
 
 int32_t sdbRead();
-int32_t sdbWrite(SSdbRawData *pRawData);
+int32_t sdbWrite(SSdbRaw *pRaw);
 int32_t sdbCommit();
 
 int32_t sdbDeploy();
diff --git a/include/dnode/mnode/transaction/trn.h b/include/dnode/mnode/transaction/trn.h
index 47ac068b54b9c04cacd0fddbd57d3676d189546b..8ba043de1269938e0f651d7d0743a3f5bf4e576a 100644
--- a/include/dnode/mnode/transaction/trn.h
+++ b/include/dnode/mnode/transaction/trn.h
@@ -24,21 +24,23 @@ extern "C" {
 #endif
 
 typedef struct STrans STrans;
+typedef enum { TRN_POLICY_ROLLBACK = 1, TRN_POLICY_RETRY = 2 } ETrnPolicy;
 
 int32_t trnInit();
 void    trnCleanup();
 
-STrans *trnCreate();
-int32_t trnPrepare(STrans *);
-int32_t trnCommit(STrans *);
-int32_t trnExecute(STrans *);
-void    trnDrop(STrans *);
-
-int32_t trnAppendRedoLog(STrans *, SSdbRawData *);
-int32_t trnAppendUndoLog(STrans *, SSdbRawData *);
-int32_t trnAppendCommitLog(STrans *, SSdbRawData *);
-int32_t trnAppendRedoAction(STrans *, SEpSet *, void *pMsg);
-int32_t trnAppendUndoAction(STrans *, SEpSet *, void *pMsg);
+STrans *trnCreate(ETrnPolicy);
+void    trnDrop(STrans *pTrans);
+void    trnSetRpcHandle(STrans *pTrans, void *rpcHandle);
+int32_t trnAppendRedoLog(STrans *pTrans, SSdbRaw *pRaw);
+int32_t trnAppendUndoLog(STrans *pTrans, SSdbRaw *pRaw);
+int32_t trnAppendCommitLog(STrans *pTrans, SSdbRaw *pRaw);
+int32_t trnAppendRedoAction(STrans *pTrans, SEpSet *, void *pMsg);
+int32_t trnAppendUndoAction(STrans *pTrans, SEpSet *, void *pMsg);
+
+int32_t trnPrepare(STrans *pTrans, int32_t (*syncfp)(SSdbRaw *pRaw, void *pData));
+int32_t trnApply(SSdbRaw *pRaw, void *pData, int32_t code);
+int32_t trnExecute(int32_t tranId);
 
 #ifdef __cplusplus
 }
diff --git a/include/util/taoserror.h b/include/util/taoserror.h
index ba3dad63aff745459947ab32ca1ef96cf15f62f7..8c4a726bf61c62f4a9ae624020521d28596e407e 100644
--- a/include/util/taoserror.h
+++ b/include/util/taoserror.h
@@ -27,6 +27,7 @@ extern "C" {
 #define TAOS_FAILED(err)                    ((err) < 0)
 
 const char* tstrerror(int32_t err);
+const char* terrstr();
 
 int32_t* taosGetErrno();
 #define terrno                              (*taosGetErrno())
diff --git a/source/dnode/mnode/impl/inc/mnodeSync.h b/source/dnode/mnode/impl/inc/mnodeSync.h
index 714d6ed1a8f856d5fb7290b3791254735082d9eb..380ad36e23926af69934ba83333149325c11ce8a 100644
--- a/source/dnode/mnode/impl/inc/mnodeSync.h
+++ b/source/dnode/mnode/impl/inc/mnodeSync.h
@@ -24,6 +24,7 @@ extern "C" {
 
 int32_t mnodeInitSync();
 void    mnodeCleanUpSync();
+int32_t mnodeSyncPropose(SSdbRaw *pRaw, void *pData);
 
 bool mnodeIsMaster();
 
diff --git a/source/dnode/mnode/impl/src/mnodeAcct.c b/source/dnode/mnode/impl/src/mnodeAcct.c
index 0811a64e926ed8f856f7d6b45c67e437f88c2bb7..e4538fa3912d6aba14058d3827f2967bb6d69c78 100644
--- a/source/dnode/mnode/impl/src/mnodeAcct.c
+++ b/source/dnode/mnode/impl/src/mnodeAcct.c
@@ -18,8 +18,8 @@
 
 #define ACCT_VER 1
 
-static SSdbRawData *mnodeAcctActionEncode(SAcctObj *pAcct) {
-  SSdbRawData *pRaw = calloc(1, sizeof(SAcctObj) + sizeof(SSdbRawData));
+static SSdbRaw *mnodeAcctActionEncode(SAcctObj *pAcct) {
+  SSdbRaw *pRaw = calloc(1, sizeof(SAcctObj) + sizeof(SSdbRaw));
   if (pRaw == NULL) {
     terrno = TSDB_CODE_MND_OUT_OF_MEMORY;
     return NULL;
@@ -45,7 +45,7 @@ static SSdbRawData *mnodeAcctActionEncode(SAcctObj *pAcct) {
   return pRaw;
 }
 
-static SAcctObj *mnodeAcctActionDecode(SSdbRawData *pRaw) {
+static SAcctObj *mnodeAcctActionDecode(SSdbRaw *pRaw) {
   if (pRaw->sver != ACCT_VER) {
     terrno = TSDB_CODE_SDB_INVAID_RAW_DATA_VER;
     return NULL;
@@ -96,23 +96,21 @@ static int32_t mnodeCreateDefaultAcct() {
   SAcctObj acctObj = {0};
   tstrncpy(acctObj.acct, TSDB_DEFAULT_USER, TSDB_USER_LEN);
   acctObj.createdTime = taosGetTimestampMs();
-  acctObj.updateTime = taosGetTimestampMs();
+  acctObj.updateTime = acctObj.createdTime;
   acctObj.acctId = 1;
-  acctObj.cfg = (SAcctCfg){.maxUsers = 128,
-                           .maxDbs = 128,
+  acctObj.cfg = (SAcctCfg){.maxUsers = 1024,
+                           .maxDbs = 1024,
                            .maxTimeSeries = INT32_MAX,
-                           .maxStreams = 1000,
+                           .maxStreams = 8092,
                            .maxStorage = INT64_MAX,
                            .accessState = TSDB_VN_ALL_ACCCESS};
 
-  SSdbRawData *pRaw = mnodeAcctActionEncode(&acctObj);
+  SSdbRaw *pRaw = mnodeAcctActionEncode(&acctObj);
   if (pRaw != NULL) {
-    code = sdbWrite(pRaw);
-  } else {
-    code = terrno;
+    return -1;
   }
 
-  return code;
+  return sdbWrite(pRaw);
 }
 
 int32_t mnodeInitAcct() {
diff --git a/source/dnode/mnode/impl/src/mnodeSync.c b/source/dnode/mnode/impl/src/mnodeSync.c
index c161bb971ac7c4a0a74e39acd915bd4a6eb209db..7541ab6b595a2206c0d4c18441355454f7c26bf6 100644
--- a/source/dnode/mnode/impl/src/mnodeSync.c
+++ b/source/dnode/mnode/impl/src/mnodeSync.c
@@ -20,4 +20,10 @@
 int32_t mnodeInitSync() { return 0; }
 void    mnodeCleanUpSync() {}
 
+int32_t mnodeSyncPropose(SSdbRaw *pRaw, void *pData) {
+  trnApply(pRaw, pData, 0);
+  free(pRaw);
+  return 0;
+}
+
 bool mnodeIsMaster() { return true; }
\ No newline at end of file
diff --git a/source/dnode/mnode/impl/src/mnodeUser.c b/source/dnode/mnode/impl/src/mnodeUser.c
index cc321f0ef0be35165b97f10a7dbc6291e94f8c2c..3b5d40d807090ca51554f891729a712c05e51430 100644
--- a/source/dnode/mnode/impl/src/mnodeUser.c
+++ b/source/dnode/mnode/impl/src/mnodeUser.c
@@ -14,15 +14,15 @@
  */
 
 #define _DEFAULT_SOURCE
+#include "mnodeSync.h"
 #include "os.h"
-#include "tkey.h"
 #include "tglobal.h"
-#include "mnodeInt.h"
+#include "tkey.h"
 
 #define USER_VER 1
 
-static SSdbRawData *mnodeUserActionEncode(SUserObj *pUser) {
-  SSdbRawData *pRaw = calloc(1, sizeof(SUserObj) + sizeof(SSdbRawData));
+static SSdbRaw *mnodeUserActionEncode(SUserObj *pUser) {
+  SSdbRaw *pRaw = calloc(1, sizeof(SUserObj) + sizeof(SSdbRaw));
   if (pRaw == NULL) {
     terrno = TSDB_CODE_MND_OUT_OF_MEMORY;
     return NULL;
@@ -43,7 +43,7 @@ static SSdbRawData *mnodeUserActionEncode(SUserObj *pUser) {
   return pRaw;
 }
 
-static SUserObj *mnodeUserActionDecode(SSdbRawData *pRaw) {
+static SUserObj *mnodeUserActionDecode(SSdbRaw *pRaw) {
   if (pRaw->sver != USER_VER) {
     terrno = TSDB_CODE_SDB_INVAID_RAW_DATA_VER;
     return NULL;
@@ -77,12 +77,14 @@ static SUserObj *mnodeUserActionDecode(SSdbRawData *pRaw) {
 static int32_t mnodeUserActionInsert(SUserObj *pUser) {
   pUser->prohibitDbHash = taosHashInit(8, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BINARY), true, HASH_ENTRY_LOCK);
   if (pUser->prohibitDbHash == NULL) {
-    return TSDB_CODE_MND_OUT_OF_MEMORY;
+    terrno = TSDB_CODE_MND_OUT_OF_MEMORY;
+    return -1;
   }
 
   pUser->pAcct = sdbAcquire(SDB_ACCT, pUser->acct);
   if (pUser->pAcct == NULL) {
-    return TSDB_CODE_MND_ACCT_NOT_EXIST;
+    terrno = TSDB_CODE_MND_ACCT_NOT_EXIST;
+    return -1;
   }
 
   return 0;
@@ -108,8 +110,6 @@ static int32_t mnodeUserActionUpdate(SUserObj *pSrcUser, SUserObj *pDstUser) {
 }
 
 static int32_t mnodeCreateDefaultUser(char *acct, char *user, char *pass) {
-  int32_t code = 0;
-
   SUserObj userObj = {0};
   tstrncpy(userObj.user, user, TSDB_USER_LEN);
   tstrncpy(userObj.acct, acct, TSDB_USER_LEN);
@@ -121,35 +121,31 @@ static int32_t mnodeCreateDefaultUser(char *acct, char *user, char *pass) {
     userObj.rootAuth = 1;
   }
 
-  SSdbRawData *pRaw = mnodeUserActionEncode(&userObj);
-  if (pRaw != NULL) {
-    code = sdbWrite(pRaw);
-  } else {
-    code = terrno;
+  SSdbRaw *pRaw = mnodeUserActionEncode(&userObj);
+  if (pRaw == NULL) {
+    return -1;
   }
 
-  return code;
+  return sdbWrite(pRaw);
 }
 
 static int32_t mnodeCreateDefaultUsers() {
-  int32_t code = mnodeCreateDefaultUser(TSDB_DEFAULT_USER, TSDB_DEFAULT_USER, TSDB_DEFAULT_PASS);
-  if (code != 0) return code;
+  if (mnodeCreateDefaultUser(TSDB_DEFAULT_USER, TSDB_DEFAULT_USER, TSDB_DEFAULT_PASS) != 0) {
+    return -1;
+  }
 
-  code = mnodeCreateDefaultUser(TSDB_DEFAULT_USER, "monitor", tsInternalPass);
-  if (code != 0) return code;
+  if (mnodeCreateDefaultUser(TSDB_DEFAULT_USER, "monitor", tsInternalPass) != 0) {
+    return -1;
+  }
 
-  code = mnodeCreateDefaultUser(TSDB_DEFAULT_USER, "_" TSDB_DEFAULT_USER, tsInternalPass);
-  if (code != 0) return code;
+  if (mnodeCreateDefaultUser(TSDB_DEFAULT_USER, "_" TSDB_DEFAULT_USER, tsInternalPass) != 0) {
+    return -1;
+  }
 
-  return code;
+  return 0;
 }
 
 static int32_t mnodeCreateUser(char *acct, char *user, char *pass, SMnMsg *pMsg) {
-  int32_t      code = 0;
-  STrans      *pTrans = NULL;
-  SSdbRawData *pUndoRaw = NULL;
-  SSdbRawData *pRedoRaw = NULL;
-
   SUserObj userObj = {0};
   tstrncpy(userObj.user, user, TSDB_USER_LEN);
   tstrncpy(userObj.acct, acct, TSDB_USER_LEN);
@@ -158,79 +154,80 @@ static int32_t mnodeCreateUser(char *acct, char *user, char *pass, SMnMsg *pMsg)
   userObj.updateTime = userObj.createdTime;
   userObj.rootAuth = 0;
 
-  pRedoRaw = mnodeUserActionEncode(&userObj);
-  if (pRedoRaw == NULL) {
-    code = terrno;
-    goto CREATE_USER_OVER;
+  STrans *pTrans = trnCreate(TRN_POLICY_ROLLBACK);
+  if (pTrans == NULL) return -1;
+
+  SSdbRaw *pRedoRaw = mnodeUserActionEncode(&userObj);
+  if (pRedoRaw == NULL || trnAppendRedoLog(pTrans, pRedoRaw) != 0) {
+    trnDrop(pTrans);
+    return -1;
   }
-  pRedoRaw->status = SDB_STATUS_READY;
+  pRedoRaw->status = SDB_STATUS_CREATING;
   pRedoRaw->action = SDB_ACTION_INSERT;
 
-  pUndoRaw = mnodeUserActionEncode(&userObj);
-  if (pUndoRaw == NULL) {
-    code = terrno;
-    goto CREATE_USER_OVER;
+  SSdbRaw *pUndoRaw = mnodeUserActionEncode(&userObj);
+  if (pUndoRaw == NULL || trnAppendUndoLog(pTrans, pUndoRaw) != 0) {
+    trnDrop(pTrans);
+    return -1;
   }
   pUndoRaw->status = SDB_STATUS_DROPPING;
   pUndoRaw->action = SDB_ACTION_DELETE;
 
-  pTrans = trnCreate();
-  if (pTrans == NULL) {
-    code = TSDB_CODE_MND_OUT_OF_MEMORY;
-    goto CREATE_USER_OVER;
+  SSdbRaw *pCommitRaw = mnodeUserActionEncode(&userObj);
+  if (pCommitRaw == NULL || trnAppendCommitLog(pTrans, pCommitRaw) != 0) {
+    trnDrop(pTrans);
+    return -1;
   }
-  trnAppendRedoLog(pTrans, pRedoRaw);
-  trnAppendUndoLog(pTrans, pUndoRaw);
+  pCommitRaw->status = SDB_STATUS_READY;
+  pCommitRaw->action = SDB_ACTION_UPDATE;
 
-  code = trnCommit(pTrans);
+  trnSetRpcHandle(pTrans, pMsg->rpcMsg.handle);
 
-CREATE_USER_OVER:
-  if (code != 0) {
+  if (trnPrepare(pTrans, mnodeSyncPropose) != 0) {
     trnDrop(pTrans);
-    free(pRedoRaw);
-    free(pUndoRaw);
+    return -1;
   }
 
-  return code;
+  trnDrop(pTrans);
+  return 0;
 }
 
 static int32_t mnodeProcessCreateUserMsg(SMnMsg *pMsg) {
   SCreateUserMsg *pCreate = pMsg->rpcMsg.pCont;
-  int32_t         code = TSDB_CODE_SUCCESS;
 
   if (pCreate->user[0] == 0) {
-    code = TSDB_CODE_MND_INVALID_USER_FORMAT;
-    mError("user:%s, failed to create since %s", pCreate->user, tstrerror(code));
-    return code;
+    terrno = TSDB_CODE_MND_INVALID_USER_FORMAT;
+    mError("user:%s, failed to create since %s", pCreate->user, terrstr());
+    return -1;
   }
 
   if (pCreate->pass[0] == 0) {
-    code = TSDB_CODE_MND_INVALID_PASS_FORMAT;
-    mError("user:%s, failed to create since %s", pCreate->user, tstrerror(code));
-    return code;
+    terrno = TSDB_CODE_MND_INVALID_PASS_FORMAT;
+    mError("user:%s, failed to create since %s", pCreate->user, terrstr());
+    return -1;
   }
 
   SUserObj *pUser = sdbAcquire(SDB_USER, pCreate->user);
   if (pUser != NULL) {
     sdbRelease(pUser);
-    code = TSDB_CODE_MND_USER_ALREADY_EXIST;
-    mError("user:%s, failed to create since %s", pCreate->user, tstrerror(code));
-    return code;
+    terrno = TSDB_CODE_MND_USER_ALREADY_EXIST;
+    mError("user:%s, failed to create since %s", pCreate->user, terrstr());
+    return -1;
   }
 
   SUserObj *pOperUser = sdbAcquire(SDB_USER, pMsg->user);
   if (pOperUser == NULL) {
-    code = TSDB_CODE_MND_NO_USER_FROM_CONN;
-    mError("user:%s, failed to create since %s", pCreate->user, tstrerror(code));
-    return code;
+    terrno = TSDB_CODE_MND_NO_USER_FROM_CONN;
+    mError("user:%s, failed to create since %s", pCreate->user, terrstr());
+    return -1;
   }
 
-  code = mnodeCreateUser(pOperUser->acct, pCreate->user, pCreate->pass, pMsg);
+  int32_t code = mnodeCreateUser(pOperUser->acct, pCreate->user, pCreate->pass, pMsg);
   sdbRelease(pOperUser);
 
   if (code != 0) {
-    mError("user:%s, failed to create since %s", pCreate->user, tstrerror(code));
-    return code;
+    mError("user:%s, failed to create since %s", pCreate->user, terrstr());
+    return -1;
   }
 
   return TSDB_CODE_MND_ACTION_IN_PROGRESS;
diff --git a/source/dnode/mnode/sdb/src/sdb.c b/source/dnode/mnode/sdb/src/sdb.c
index a47ed8ec20598ca3e37f526677077ec92c0b32d3..d3b825e190453572b9fbd518c9718bffd14d0f26 100644
--- a/source/dnode/mnode/sdb/src/sdb.c
+++ b/source/dnode/mnode/sdb/src/sdb.c
@@ -61,7 +61,7 @@ static SHashObj *sdbGetHash(int32_t sdb) {
   return hash;
 }
 
-int32_t sdbWrite(SSdbRawData *pRaw) {
+int32_t sdbWrite(SSdbRaw *pRaw) {
   SHashObj *hash = sdbGetHash(pRaw->type);
   switch (pRaw->action) {
     case SDB_ACTION_INSERT:
@@ -85,7 +85,7 @@ static int32_t sdbReadVersion(FileFd fd) { return 0; }
 static int32_t sdbReadDataFile() {
   int32_t code = 0;
 
-  SSdbRawData *pRaw = malloc(SDB_MAX_SIZE);
+  SSdbRaw *pRaw = malloc(SDB_MAX_SIZE);
   if (pRaw == NULL) {
     return TSDB_CODE_MND_OUT_OF_MEMORY;
   }
@@ -101,7 +101,7 @@ static int32_t sdbReadDataFile() {
 
   int64_t offset = 0;
   while (1) {
-    int32_t ret = (int32_t)taosReadFile(fd, pRaw, sizeof(SSdbRawData));
+    int32_t ret = (int32_t)taosReadFile(fd, pRaw, sizeof(SSdbRaw));
     if (ret == 0) break;
 
     if (ret < 0) {
@@ -110,7 +110,7 @@ static int32_t sdbReadDataFile() {
       break;
     }
 
-    if (ret < sizeof(SSdbRawData)) {
+    if (ret < sizeof(SSdbRaw)) {
       code = TSDB_CODE_SDB_INTERNAL_ERROR;
       mError("failed to read file:%s since %s", file, tstrerror(code));
       break;
@@ -143,7 +143,7 @@ static int32_t sdbWriteDataFile() {
     return code;
   }
 
-  for (int32_t i = SDB_START; i < SDB_MAX; ++i) {
+  for (int32_t i = SDB_MAX - 1; i > SDB_START; --i) {
     SHashObj *hash = tsSdb.hashObjs[i];
     if (!hash) continue;
 
@@ -153,9 +153,9 @@ static int32_t sdbWriteDataFile() {
     SSdbRow *pRow = taosHashIterate(hash, NULL);
     while (pRow != NULL) {
       if (pRow->status == SDB_STATUS_READY) continue;
-      SSdbRawData *pRaw = (*encodeFp)(pRow->data);
+      SSdbRaw *pRaw = (*encodeFp)(pRow->data);
       if (pRaw != NULL) {
-        taosWriteFile(fd, pRaw, sizeof(SSdbRawData) + pRaw->dataLen);
+        taosWriteFile(fd, pRaw, sizeof(SSdbRaw) + pRaw->dataLen);
       } else {
         taosHashCancelIterate(hash, pRow);
         code = TSDB_CODE_SDB_INTERNAL_ERROR;
diff --git a/source/dnode/mnode/transaction/CMakeLists.txt b/source/dnode/mnode/transaction/CMakeLists.txt
index 6b01f5bd18d809f4f222818005a9978ec1bcada8..d35a8c9b3ff045a4e36af3e261576c3d29ba3b57 100644
--- a/source/dnode/mnode/transaction/CMakeLists.txt
+++ b/source/dnode/mnode/transaction/CMakeLists.txt
@@ -11,4 +11,5 @@ target_link_libraries(
     PRIVATE common
     PRIVATE util
     PRIVATE sdb
+    PRIVATE transport
 )
diff --git a/source/dnode/mnode/transaction/inc/trnInt.h b/source/dnode/mnode/transaction/inc/trnInt.h
index 74c64f673faae6374b63816ae7d37c4c905baeb6..03860734ee00fa91c3963a41de6beafcdcb6b169 100644
--- a/source/dnode/mnode/transaction/inc/trnInt.h
+++ b/source/dnode/mnode/transaction/inc/trnInt.h
@@ -33,14 +33,35 @@ extern "C" {
 #define mDebug(...) { if (mDebugFlag & DEBUG_DEBUG) { taosPrintLog("MND ", mDebugFlag, __VA_ARGS__); }}
 #define mTrace(...) { if (mDebugFlag & DEBUG_TRACE) { taosPrintLog("MND ", mDebugFlag, __VA_ARGS__); }}
 
+#define TRN_VER 1
+#define TRN_DEFAULT_ARRAY_SIZE 8
+
+typedef enum {
+  TRN_STAGE_PREPARE = 1,
+  TRN_STAGE_EXECUTE = 2,
+  TRN_STAGE_COMMIT = 3,
+  TRN_STAGE_ROLLBACK = 4,
+  TRN_STAGE_RETRY = 5
+} ETrnStage;
+
 typedef struct STrans {
-  SArray *redoLogs;
-  SArray *undoLogs;
-  SArray *commitLogs;
-  SArray *redoActions;
-  SArray *undoActions;
+  int32_t    id;
+  ETrnStage  stage;
+  ETrnPolicy policy;
+  void      *rpcHandle;
+  SArray    *redoLogs;
+  SArray    *undoLogs;
+  SArray    *commitLogs;
+  SArray    *redoActions;
+  SArray    *undoActions;
 } STrans;
 
+SSdbRaw *trnActionEncode(STrans *pTrans);
+STrans  *trnActionDecode(SSdbRaw *pRaw);
+int32_t  trnActionInsert(STrans *pTrans);
+int32_t  trnActionDelete(STrans *pTrans);
+int32_t  trnActionUpdate(STrans *pSrcTrans, STrans *pDstTrans);
+int32_t  trnGenerateTransId();
 
 #ifdef __cplusplus
 }
diff --git a/source/dnode/mnode/transaction/src/trnInt.c b/source/dnode/mnode/transaction/src/trnInt.c
new file mode 100644
index 0000000000000000000000000000000000000000..4a69007de5e7d9996a489a7af050cfb528e39654
--- /dev/null
+++ b/source/dnode/mnode/transaction/src/trnInt.c
@@ -0,0 +1,164 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#define _DEFAULT_SOURCE
+#include "trnInt.h"
+
+SSdbRaw *trnActionEncode(STrans *pTrans) {
+  int32_t rawDataLen = 5 * sizeof(int32_t);
+  int32_t redoLogNum = taosArrayGetSize(pTrans->redoLogs);
+  int32_t undoLogNum = taosArrayGetSize(pTrans->undoLogs);
+  int32_t commitLogNum = taosArrayGetSize(pTrans->commitLogs);
+  int32_t redoActionNum = taosArrayGetSize(pTrans->redoActions);
+  int32_t undoActionNum = taosArrayGetSize(pTrans->undoActions);
+
+  for (int32_t index = 0; index < redoLogNum; ++index) {
+    SSdbRaw *pRawData = taosArrayGet(pTrans->redoLogs, index);
+    rawDataLen += (sizeof(SSdbRaw) + pRawData->dataLen);
+  }
+
+  for (int32_t index = 0; index < undoLogNum; ++index) {
+    SSdbRaw *pRawData = taosArrayGet(pTrans->undoLogs, index);
+    rawDataLen += (sizeof(SSdbRaw) + pRawData->dataLen);
+  }
+
+  for (int32_t index = 0; index < commitLogNum; ++index) {
+    SSdbRaw *pRawData = taosArrayGet(pTrans->commitLogs, index);
+    rawDataLen += (sizeof(SSdbRaw) + pRawData->dataLen);
+  }
+
+  SSdbRaw *pRaw = calloc(1, rawDataLen + sizeof(SSdbRaw));
+  if (pRaw == NULL) {
+    terrno = TSDB_CODE_MND_OUT_OF_MEMORY;
+    return NULL;
+  }
+
+  int32_t dataLen = 0;
+  char   *pData = pRaw->data;
+  SDB_SET_INT32_VAL(pData, dataLen, redoLogNum)
+  SDB_SET_INT32_VAL(pData, dataLen, undoLogNum)
+  SDB_SET_INT32_VAL(pData, dataLen, commitLogNum)
+  SDB_SET_INT32_VAL(pData, dataLen, redoActionNum)
+  SDB_SET_INT32_VAL(pData, dataLen, undoActionNum)
+
+  pRaw->dataLen = dataLen;
+  pRaw->type = SDB_TRANS;
+  pRaw->sver = TRN_VER;
+  return pRaw;
+}
+
+STrans *trnActionDecode(SSdbRaw *pRaw) {
+  if (pRaw->sver != TRN_VER) {
+    terrno = TSDB_CODE_SDB_INVAID_RAW_DATA_VER;
+    return NULL;
+  }
+
+  STrans *pTrans = NULL;
+  if (pTrans == NULL) {
+    terrno = TSDB_CODE_MND_OUT_OF_MEMORY;
+    return NULL;
+  }
+
+  int32_t  redoLogNum = 0;
+  int32_t  undoLogNum = 0;
+  int32_t  commitLogNum = 0;
+  int32_t  redoActionNum = 0;
+  int32_t  undoActionNum = 0;
+  SSdbRaw *pTmp = malloc(sizeof(SSdbRaw));
+
+  int32_t code = 0;
+  int32_t dataLen = pRaw->dataLen;
+  char   *pData = pRaw->data;
+  SDB_GET_INT32_VAL(pData, dataLen, redoLogNum, code)
+  SDB_GET_INT32_VAL(pData, dataLen, undoLogNum, code)
+  SDB_GET_INT32_VAL(pData, dataLen, commitLogNum, code)
+  SDB_GET_INT32_VAL(pData, dataLen, redoActionNum, code)
+  SDB_GET_INT32_VAL(pData, dataLen, undoActionNum, code)
+
+  for (int32_t index = 0; index < redoLogNum; ++index) {
+    SDB_GET_BINARY_VAL(pData, dataLen, pTmp, sizeof(SSdbRaw), code);
+    if (code == 0 && pTmp->dataLen > 0) {
+      SSdbRaw *pRead = malloc(sizeof(SSdbRaw) + pTmp->dataLen);
+      if (pRead == NULL) {
+        code = TSDB_CODE_MND_OUT_OF_MEMORY;
+        break;
+      }
+      memcpy(pRead, pTmp, sizeof(SSdbRaw));
+      SDB_GET_BINARY_VAL(pData, dataLen, pRead->data, pRead->dataLen, code);
+      void *ret = taosArrayPush(pTrans->redoLogs, &pRead);
+      if (ret == NULL) {
+        code = TSDB_CODE_MND_OUT_OF_MEMORY;
+        break;
+      }
+    }
+  }
+
+  if (code != 0) {
+    trnDrop(pTrans);
+    terrno = code;
+    return NULL;
+  }
+
+  return pTrans;
+}
+
+int32_t trnActionInsert(STrans *pTrans) {
+  SArray *pArray = pTrans->redoLogs;
+  int32_t arraySize = taosArrayGetSize(pArray);
+
+  for (int32_t index = 0; index < arraySize; ++index) {
+    SSdbRaw *pRaw = taosArrayGetP(pArray, index);
+    int32_t  code = sdbWrite(pRaw);
+    if (code != 0) {
+      return code;
+    }
+  }
+
+  return 0;
+}
+
+int32_t trnActionDelete(STrans *pTrans) {
+  SArray *pArray = pTrans->redoLogs;
+  int32_t arraySize = taosArrayGetSize(pArray);
+
+  for (int32_t index = 0; index < arraySize; ++index) {
+    SSdbRaw *pRaw = taosArrayGetP(pArray, index);
+    int32_t  code = sdbWrite(pRaw);
+    if (code != 0) {
+      return code;
+    }
+  }
+
+  return 0;
+}
+
+int32_t trnActionUpdate(STrans *pSrcTrans, STrans *pDstTrans) { return 0; }
+
+int32_t trnGenerateTransId() { return 1; }
+
+int32_t trnInit() {
+  SSdbDesc desc = {.sdbType = SDB_TRANS,
+                   .keyType = SDB_KEY_INT32,
+                   .encodeFp = (SdbEncodeFp)trnActionEncode,
+                   .decodeFp = (SdbDecodeFp)trnActionDecode,
+                   .insertFp = (SdbInsertFp)trnActionInsert,
+                   .updateFp = (SdbUpdateFp)trnActionUpdate,
+                   .deleteFp = (SdbDeleteFp)trnActionDelete};
+  sdbSetHandler(desc);
+
+  return 0;
+}
+
+void trnCleanup() {}
diff --git a/source/dnode/mnode/transaction/src/trnMain.c b/source/dnode/mnode/transaction/src/trnMain.c
index c0c0deae7c7f3e7b574136461223f595442b760f..3ff991a676e71e8ff5e6f4bfad7410e30e2d0f8a 100644
--- a/source/dnode/mnode/transaction/src/trnMain.c
+++ b/source/dnode/mnode/transaction/src/trnMain.c
@@ -15,17 +15,18 @@
 
 #define _DEFAULT_SOURCE
 #include "trnInt.h"
+#include "trpc.h"
 
-#define TRN_VER 1
-#define TRN_DEFAULT_ARRAY_SIZE 8
-
-STrans *trnCreate() {
+STrans *trnCreate(ETrnPolicy policy) {
   STrans *pTrans = calloc(1, sizeof(STrans));
   if (pTrans == NULL) {
     terrno = TSDB_CODE_MND_OUT_OF_MEMORY;
     return NULL;
   }
 
+  pTrans->id = trnGenerateTransId();
+  pTrans->stage = TRN_STAGE_PREPARE;
+  pTrans->policy = policy;
   pTrans->redoLogs = taosArrayInit(TRN_DEFAULT_ARRAY_SIZE, sizeof(void *));
   pTrans->undoLogs = taosArrayInit(TRN_DEFAULT_ARRAY_SIZE, sizeof(void *));
   pTrans->commitLogs = taosArrayInit(TRN_DEFAULT_ARRAY_SIZE, sizeof(void *));
@@ -34,7 +35,6 @@ STrans *trnCreate() {
 
   if (pTrans->redoLogs == NULL || pTrans->undoLogs == NULL || pTrans->commitLogs == NULL ||
       pTrans->redoActions == NULL || pTrans->undoActions == NULL) {
-    trnDrop(pTrans);
     terrno = TSDB_CODE_MND_OUT_OF_MEMORY;
     return NULL;
   }
@@ -42,192 +42,156 @@ STrans *trnCreate() {
   return pTrans;
 }
 
-int32_t trnCommit(STrans *pTrans) { return 0; }
-
-static void trnDropLogs(SArray *pArray) {
+static void trnDropArray(SArray *pArray) {
   for (int32_t index = 0; index < pArray->size; ++index) {
-    SSdbRawData *pRaw = taosArrayGetP(pArray, index);
-    free(pRaw);
+    SSdbRaw *pRaw = taosArrayGetP(pArray, index);
+    tfree(pRaw);
   }
 
   taosArrayDestroy(pArray);
 }
 
 void trnDrop(STrans *pTrans) {
-  trnDropLogs(pTrans->redoLogs);
-  trnDropLogs(pTrans->undoLogs);
-  trnDropLogs(pTrans->commitLogs);
-  free(pTrans);
+  trnDropArray(pTrans->redoLogs);
+  trnDropArray(pTrans->undoLogs);
+  trnDropArray(pTrans->commitLogs);
+  trnDropArray(pTrans->redoActions);
+  trnDropArray(pTrans->undoActions);
+  tfree(pTrans);
 }
 
-int32_t trnAppendRedoLog(STrans *pTrans, SSdbRawData *pRaw) {
-  void *ptr = taosArrayPush(pTrans->redoLogs, &pRaw);
-  if (ptr == NULL) {
-    return TSDB_CODE_MND_OUT_OF_MEMORY;
+void trnSetRpcHandle(STrans *pTrans, void *rpcHandle) {
+  if (pTrans != NULL) {
+    pTrans->rpcHandle = rpcHandle;
   }
-  return 0;
 }
 
-int32_t trnAppendUndoLog(STrans *pTrans, SSdbRawData *pRaw) {
-  void *ptr = taosArrayPush(pTrans->undoLogs, &pRaw);
-  if (ptr == NULL) {
-    return TSDB_CODE_MND_OUT_OF_MEMORY;
+static int32_t trnAppendArray(SArray *pArray, SSdbRaw *pRaw) {
+  if (pArray == NULL || pRaw == NULL) {
+    terrno = TSDB_CODE_MND_OUT_OF_MEMORY;
+    return -1;
   }
-  return 0;
-}
 
-int32_t trnAppendCommitLog(STrans *pTrans, SSdbRawData *pRaw) {
-  void *ptr = taosArrayPush(pTrans->commitLogs, &pRaw);
+  void *ptr = taosArrayPush(pArray, &pRaw);
   if (ptr == NULL) {
-    return TSDB_CODE_MND_OUT_OF_MEMORY;
+    terrno = TSDB_CODE_MND_OUT_OF_MEMORY;
+    return -1;
   }
+
   return 0;
 }
 
+int32_t trnAppendRedoLog(STrans *pTrans, SSdbRaw *pRaw) { return trnAppendArray(pTrans->redoLogs, pRaw); }
+
+int32_t trnAppendUndoLog(STrans *pTrans, SSdbRaw *pRaw) { return trnAppendArray(pTrans->undoLogs, pRaw); }
+
+int32_t trnAppendCommitLog(STrans *pTrans, SSdbRaw *pRaw) { return trnAppendArray(pTrans->commitLogs, pRaw); }
+
 int32_t trnAppendRedoAction(STrans *pTrans, SEpSet *pEpSet, void *pMsg) {
-  void *ptr = taosArrayPush(pTrans->redoActions, &pMsg);
-  if (ptr == NULL) {
-    return TSDB_CODE_MND_OUT_OF_MEMORY;
-  }
-  return 0;
+  return trnAppendArray(pTrans->redoActions, pMsg);
 }
 
 int32_t trnAppendUndoAction(STrans *pTrans, SEpSet *pEpSet, void *pMsg) {
-  void *ptr = taosArrayPush(pTrans->undoActions, &pMsg);
-  if (ptr == NULL) {
-    return TSDB_CODE_MND_OUT_OF_MEMORY;
-  }
-  return 0;
+  return trnAppendArray(pTrans->undoActions, pMsg);
 }
 
-static SSdbRawData *trnActionEncode(STrans *pTrans) {
-  int32_t rawDataLen = 5 * sizeof(int32_t);
-  int32_t redoLogNum = taosArrayGetSize(pTrans->redoLogs);
-  int32_t undoLogNum = taosArrayGetSize(pTrans->undoLogs);
-  int32_t commitLogNum = taosArrayGetSize(pTrans->commitLogs);
-  int32_t redoActionNum = taosArrayGetSize(pTrans->redoActions);
-  int32_t undoActionNum = taosArrayGetSize(pTrans->undoActions);
+int32_t trnPrepare(STrans *pTrans, int32_t (*syncfp)(SSdbRaw *pRaw, void *pData)) {
+  if (syncfp == NULL) return -1;
 
-  for (int32_t index = 0; index < redoLogNum; ++index) {
-    SSdbRawData *pRawData = taosArrayGet(pTrans->redoLogs, index);
-    rawDataLen += (sizeof(SSdbRawData) + pRawData->dataLen);
+  SSdbRaw *pRaw = trnActionEncode(pTrans);
+  if (pRaw == NULL) {
+    mError("tranId:%d, failed to decode trans since %s", pTrans->id, terrstr());
+    return -1;
   }
 
-  for (int32_t index = 0; index < undoLogNum; ++index) {
-    SSdbRawData *pRawData = taosArrayGet(pTrans->undoLogs, index);
-    rawDataLen += (sizeof(SSdbRawData) + pRawData->dataLen);
+  if (sdbWrite(pRaw) != 0) {
+    mError("tranId:%d, failed to write trans since %s", pTrans->id, terrstr());
+    return -1;
   }
 
-  for (int32_t index = 0; index < commitLogNum; ++index) {
-    SSdbRawData *pRawData = taosArrayGet(pTrans->commitLogs, index);
-    rawDataLen += (sizeof(SSdbRawData) + pRawData->dataLen);
+  if ((*syncfp)(pRaw, pTrans->rpcHandle) != 0) {
+    mError("tranId:%d, failed to sync trans since %s", pTrans->id, terrstr());
+    return -1;
   }
 
-  SSdbRawData *pRaw = calloc(1, rawDataLen + sizeof(SSdbRawData));
-  if (pRaw == NULL) {
-    terrno = TSDB_CODE_MND_OUT_OF_MEMORY;
-    return NULL;
-  }
-
-  int32_t dataLen = 0;
-  char   *pData = pRaw->data;
-  SDB_SET_INT32_VAL(pData, dataLen, redoLogNum)
-  SDB_SET_INT32_VAL(pData, dataLen, undoLogNum)
-  SDB_SET_INT32_VAL(pData, dataLen, commitLogNum)
-  SDB_SET_INT32_VAL(pData, dataLen, redoActionNum)
-  SDB_SET_INT32_VAL(pData, dataLen, undoActionNum)
-
-  pRaw->dataLen = dataLen;
-  pRaw->type = SDB_TRANS;
-  pRaw->sver = TRN_VER;
-  return pRaw;
+  return 0;
 }
 
-static STrans *trnActionDecode(SSdbRawData *pRaw) {
-  if (pRaw->sver != TRN_VER) {
-    terrno = TSDB_CODE_SDB_INVAID_RAW_DATA_VER;
-    return NULL;
+static void trnSendRpcRsp(void *rpcHandle, int32_t code) {
+  if (rpcHandle != NULL) {
+    SRpcMsg rspMsg = {.handle = rpcHandle, .code = terrno};
+    rpcSendResponse(&rspMsg);
   }
+}
 
-  STrans *pTrans = trnCreate();
-  if (pTrans == NULL) {
-    terrno = TSDB_CODE_MND_OUT_OF_MEMORY;
-    return NULL;
-  }
-
-  int32_t redoLogNum = 0;
-  int32_t undoLogNum = 0;
-  int32_t commitLogNum = 0;
-  int32_t redoActionNum = 0;
-  int32_t undoActionNum = 0;
-  SSdbRawData *pTmp = malloc(sizeof(SSdbRawData));
-
-  int32_t code = 0;
-  int32_t dataLen = pRaw->dataLen;
-  char   *pData = pRaw->data;
-  SDB_GET_INT32_VAL(pData, dataLen, redoLogNum, code)
-  SDB_GET_INT32_VAL(pData, dataLen, undoLogNum, code)
-  SDB_GET_INT32_VAL(pData, dataLen, commitLogNum, code)
-  SDB_GET_INT32_VAL(pData, dataLen, redoActionNum, code)
-  SDB_GET_INT32_VAL(pData, dataLen, undoActionNum, code)
-
-  for (int32_t index = 0; index < redoLogNum; ++index) {
-    SDB_GET_BINARY_VAL(pData, dataLen, pTmp, sizeof(SSdbRawData), code);
-    if (code == 0 && pTmp->dataLen > 0) {
-      SSdbRawData *pRead = malloc(sizeof(SSdbRawData) + pTmp->dataLen);
-      if (pRead == NULL) {
-        code = TSDB_CODE_MND_OUT_OF_MEMORY;
-        break;
-      }
-      memcpy(pRead, pTmp, sizeof(SSdbRawData));
-      SDB_GET_BINARY_VAL(pData, dataLen, pRead->data, pRead->dataLen, code);
-      void *ret = taosArrayPush(pTrans->redoLogs, &pRead);
-      if (ret == NULL) {
-        code = TSDB_CODE_MND_OUT_OF_MEMORY;
-        break;
-      }
-    }
+int32_t trnApply(SSdbRaw *pRaw, void *pData, int32_t code) {
+  if (code != 0) {
+    trnSendRpcRsp(pData, terrno);
+    return 0;
   }
 
-  if (code != 0) {
-    trnDrop(pTrans);
+  if (sdbWrite(pRaw) != 0) {
+    code = terrno;
+    trnSendRpcRsp(pData, code);
     terrno = code;
-    return NULL;
+    return -1;
   }
 
-  return pTrans;
+  return 0;
 }
 
-static int32_t trnActionInsert(STrans *pTrans) {
-  SArray *pArray = pTrans->redoLogs;
-  int32_t arraySize = taosArrayGetSize(pArray);
+int32_t trnExecuteRedoLogs(STrans *pTrans) {return 0;}
+int32_t trnExecuteUndoLogs(STrans *pTrans) {return 0;}
+int32_t trnExecuteCommitLogs(STrans *pTrans) {return 0;}
+int32_t trnExecuteRedoActions(STrans *pTrans) {return 0;}
+int32_t trnExecuteUndoActions(STrans *pTrans) {return 0;}
+static int32_t trnPerfomRollbackStage(STrans *pTrans) { return 0; }
 
-  for (int32_t index = 0; index < arraySize; ++index) {
-    SSdbRawData *pRaw = taosArrayGetP(pArray, index);
-    int32_t      code = sdbWrite(pRaw);
-    if (code != 0) {
-      return code;
-    }
+int32_t trnExecute(int32_t tranId) {
+  int32_t code = 0;
+
+  STrans *pTrans = sdbAcquire(SDB_TRANS, &tranId);
+  if (pTrans == NULL) {
+    code = terrno;
+    return code;
   }
 
-  return 0;
-}
+  if (pTrans->stage == TRN_STAGE_PREPARE) {
+    code = trnExecuteRedoLogs(pTrans);
+    if (code == 0) {
+      pTrans->stage = TRN_STAGE_EXECUTE;
+    } else {
+      pTrans->stage = TRN_STAGE_ROLLBACK;
+    }
+  }
 
-static int32_t trnActionDelete(STrans *pTrans) {
-  SArray *pArray = pTrans->redoLogs;
-  int32_t arraySize = taosArrayGetSize(pArray);
+  if (pTrans->stage == TRN_STAGE_EXECUTE) {
+    code = trnExecuteRedoActions(pTrans);
+    if (code == 0) {
+      pTrans->stage = TRN_STAGE_COMMIT;
+    } else if (code == TSDB_CODE_MND_ACTION_IN_PROGRESS) {
+      // do nothing
+    } else {
+      if (pTrans->policy == TRN_POLICY_RETRY) {
+        pTrans->stage = TRN_STAGE_RETRY;
+      } else {
+        pTrans->stage = TRN_STAGE_ROLLBACK;
+      }
+    }
+  }
 
-  for (int32_t index = 0; index < arraySize; ++index) {
-    SSdbRawData *pRaw = taosArrayGetP(pArray, index);
-    int32_t      code = sdbWrite(pRaw);
-    if (code != 0) {
-      return code;
+  if (pTrans->stage == TRN_STAGE_COMMIT) {
+    code = trnExecuteCommitLogs(pTrans);
+    if (code == 0) {
+      trnDrop(pTrans);
     }
   }
 
-  return 0;
-}
+  if (pTrans->stage == TRN_STAGE_ROLLBACK) {
+  }
+
+  if (pTrans->stage == TRN_STAGE_RETRY) {
+  }
 
-static int32_t trnActionUpdate(STrans *pSrcUser, STrans *pDstUser) {
   return 0;
-}
+}
\ No newline at end of file
diff --git a/source/dnode/mnode/transaction/src/trnThread.c b/source/dnode/mnode/transaction/src/trnThread.c
deleted file mode 100644
index 6340f401b121cadb1eb479ac744203f8c0bfe63b..0000000000000000000000000000000000000000
--- a/source/dnode/mnode/transaction/src/trnThread.c
+++ /dev/null
@@ -1,46 +0,0 @@
-/*
- * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
- *
- * This program is free software: you can use, redistribute, and/or modify
- * it under the terms of the GNU Affero General Public License, version 3
- * or later ("AGPL"), as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-#define _DEFAULT_SOURCE
-#include "trnInt.h"
-#include "tthread.h"
-
-static struct {
-  pthread_t *threadId;
-  bool       threadRunning;
-} tsTrn;
-
-static void *trnThreadFunc(void *param) {
-  while (1) {
-    pthread_testcancel();
-  }
-  return NULL;
-}
-
-int32_t trnInit() {
-  tsTrn.threadId = taosCreateThread(trnThreadFunc, NULL);
-  if (tsTrn.threadId == NULL) {
-    return TSDB_CODE_MND_OUT_OF_MEMORY;
-  }
-
-  return 0;
-}
-
-void trnCleanup() {
-  if (tsTrn.threadId) {
-    taosDestoryThread(tsTrn.threadId);
-    tsTrn.threadId = NULL;
-  }
-}
diff --git a/source/util/src/terror.c b/source/util/src/terror.c
index 2003270b2168d7f023f3718e1d8333a6b17d7994..4151178e2e0ea4448588e4676fa9d1ea20501245 100644
--- a/source/util/src/terror.c
+++ b/source/util/src/terror.c
@@ -524,3 +524,5 @@ const char* tstrerror(int32_t err) {
 
   return "";
 }
+
+const char* terrstr() { return tstrerror(terrno); }
\ No newline at end of file