diff --git a/include/dnode/mnode/sdb/sdb.h b/include/dnode/mnode/sdb/sdb.h
index f302a21c7a4b78af8d0f436796c2dc661fa60bae..6e4e476b3ee43a30fb2e9aea24a94f034c7c367b 100644
--- a/include/dnode/mnode/sdb/sdb.h
+++ b/include/dnode/mnode/sdb/sdb.h
@@ -21,7 +21,7 @@ extern "C" {
 #endif
 
 #define SDB_GET_BINARY_VAL(pData, dataLen, val, valLen, code) \
-  {                                                           \
+  if (code == 0) {                                            \
     if ((dataLen) >= (valLen)) {                              \
       memcpy((val), (char *)(pData), (valLen));               \
       (dataLen) -= (valLen);                                  \
@@ -32,7 +32,7 @@ extern "C" {
   }
 
 #define SDB_GET_INT32_VAL(pData, dataLen, val, code) \
-  {                                                  \
+  if (code == 0) {                                   \
     if (dataLen >= sizeof(int32_t)) {                \
       *(int32_t *)(pData) = (int32_t)(val);          \
       (dataLen) -= sizeof(int32_t);                  \
@@ -43,7 +43,7 @@ extern "C" {
   }
 
 #define SDB_GET_INT64_VAL(pData, dataLen, val, code) \
-  {                                                  \
+  if (code == 0) {                                   \
     if (dataLen >= sizeof(int64_t)) {                \
       *(int64_t *)(pData) = (int64_t)(val);          \
       (dataLen) -= sizeof(int64_t);                  \
@@ -87,7 +87,7 @@ typedef enum {
   SDB_VGROUP = 9,
   SDB_STABLE = 10,
   SDB_FUNC = 11,
-  SDB_OPER = 12,
+  SDB_TRANS = 12,
   SDB_MAX = 13
 } ESdbType;
 
diff --git a/include/dnode/mnode/transaction/trn.h b/include/dnode/mnode/transaction/trn.h
index 62aa326682d44689e4025906769c4bc752147c5d..47ac068b54b9c04cacd0fddbd57d3676d189546b 100644
--- a/include/dnode/mnode/transaction/trn.h
+++ b/include/dnode/mnode/transaction/trn.h
@@ -29,7 +29,9 @@ 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 *);
diff --git a/source/dnode/mnode/transaction/inc/trnInt.h b/source/dnode/mnode/transaction/inc/trnInt.h
index c5d57d10200614a350b4eb50a6527d877566e7d0..74c64f673faae6374b63816ae7d37c4c905baeb6 100644
--- a/source/dnode/mnode/transaction/inc/trnInt.h
+++ b/source/dnode/mnode/transaction/inc/trnInt.h
@@ -41,6 +41,7 @@ typedef struct STrans {
   SArray *undoActions;
 } STrans;
 
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/source/dnode/mnode/transaction/src/trn.c b/source/dnode/mnode/transaction/src/trn.c
index 850880d16dd5b706686aa4f5f23dd95f9c63e1df..c0c0deae7c7f3e7b574136461223f595442b760f 100644
--- a/source/dnode/mnode/transaction/src/trn.c
+++ b/source/dnode/mnode/transaction/src/trn.c
@@ -16,11 +16,9 @@
 #define _DEFAULT_SOURCE
 #include "trnInt.h"
 
+#define TRN_VER 1
 #define TRN_DEFAULT_ARRAY_SIZE 8
 
-int32_t trnInit() { return 0; }
-void    trnCleanup();
-
 STrans *trnCreate() {
   STrans *pTrans = calloc(1, sizeof(STrans));
   if (pTrans == NULL) {
@@ -36,12 +34,7 @@ STrans *trnCreate() {
 
   if (pTrans->redoLogs == NULL || pTrans->undoLogs == NULL || pTrans->commitLogs == NULL ||
       pTrans->redoActions == NULL || pTrans->undoActions == NULL) {
-    taosArrayDestroy(pTrans->redoLogs);
-    taosArrayDestroy(pTrans->undoLogs);
-    taosArrayDestroy(pTrans->commitLogs);
-    taosArrayDestroy(pTrans->redoActions);
-    taosArrayDestroy(pTrans->undoActions);
-    free(pTrans);
+    trnDrop(pTrans);
     terrno = TSDB_CODE_MND_OUT_OF_MEMORY;
     return NULL;
   }
@@ -50,7 +43,22 @@ STrans *trnCreate() {
 }
 
 int32_t trnCommit(STrans *pTrans) { return 0; }
-void    trnDrop(STrans *pTrans) {}
+
+static void trnDropLogs(SArray *pArray) {
+  for (int32_t index = 0; index < pArray->size; ++index) {
+    SSdbRawData *pRaw = taosArrayGetP(pArray, index);
+    free(pRaw);
+  }
+
+  taosArrayDestroy(pArray);
+}
+
+void trnDrop(STrans *pTrans) {
+  trnDropLogs(pTrans->redoLogs);
+  trnDropLogs(pTrans->undoLogs);
+  trnDropLogs(pTrans->commitLogs);
+  free(pTrans);
+}
 
 int32_t trnAppendRedoLog(STrans *pTrans, SSdbRawData *pRaw) {
   void *ptr = taosArrayPush(pTrans->redoLogs, &pRaw);
@@ -91,3 +99,135 @@ int32_t trnAppendUndoAction(STrans *pTrans, SEpSet *pEpSet, void *pMsg) {
   }
   return 0;
 }
+
+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);
+
+  for (int32_t index = 0; index < redoLogNum; ++index) {
+    SSdbRawData *pRawData = taosArrayGet(pTrans->redoLogs, index);
+    rawDataLen += (sizeof(SSdbRawData) + pRawData->dataLen);
+  }
+
+  for (int32_t index = 0; index < undoLogNum; ++index) {
+    SSdbRawData *pRawData = taosArrayGet(pTrans->undoLogs, index);
+    rawDataLen += (sizeof(SSdbRawData) + pRawData->dataLen);
+  }
+
+  for (int32_t index = 0; index < commitLogNum; ++index) {
+    SSdbRawData *pRawData = taosArrayGet(pTrans->commitLogs, index);
+    rawDataLen += (sizeof(SSdbRawData) + pRawData->dataLen);
+  }
+
+  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;
+}
+
+static STrans *trnActionDecode(SSdbRawData *pRaw) {
+  if (pRaw->sver != TRN_VER) {
+    terrno = TSDB_CODE_SDB_INVAID_RAW_DATA_VER;
+    return NULL;
+  }
+
+  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;
+      }
+    }
+  }
+
+  if (code != 0) {
+    trnDrop(pTrans);
+    terrno = code;
+    return NULL;
+  }
+
+  return pTrans;
+}
+
+static int32_t trnActionInsert(STrans *pTrans) {
+  SArray *pArray = pTrans->redoLogs;
+  int32_t arraySize = taosArrayGetSize(pArray);
+
+  for (int32_t index = 0; index < arraySize; ++index) {
+    SSdbRawData *pRaw = taosArrayGetP(pArray, index);
+    int32_t      code = sdbWrite(pRaw);
+    if (code != 0) {
+      return code;
+    }
+  }
+
+  return 0;
+}
+
+static int32_t trnActionDelete(STrans *pTrans) {
+  SArray *pArray = pTrans->redoLogs;
+  int32_t arraySize = taosArrayGetSize(pArray);
+
+  for (int32_t index = 0; index < arraySize; ++index) {
+    SSdbRawData *pRaw = taosArrayGetP(pArray, index);
+    int32_t      code = sdbWrite(pRaw);
+    if (code != 0) {
+      return code;
+    }
+  }
+
+  return 0;
+}
+
+static int32_t trnActionUpdate(STrans *pSrcUser, STrans *pDstUser) {
+  return 0;
+}
diff --git a/source/dnode/mnode/transaction/src/trnThread.c b/source/dnode/mnode/transaction/src/trnThread.c
new file mode 100644
index 0000000000000000000000000000000000000000..6340f401b121cadb1eb479ac744203f8c0bfe63b
--- /dev/null
+++ b/source/dnode/mnode/transaction/src/trnThread.c
@@ -0,0 +1,46 @@
+/*
+ * 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;
+  }
+}