diff --git a/.devcontainer/Dockerfile b/.devcontainer/Dockerfile
new file mode 100644
index 0000000000..fc9a51af65
--- /dev/null
+++ b/.devcontainer/Dockerfile
@@ -0,0 +1,9 @@
+# See here for image contents: https://github.com/microsoft/vscode-dev-containers/tree/v0.209.3/containers/cpp/.devcontainer/base.Dockerfile
+
+# [Choice] Debian / Ubuntu version (use Debian 11/9, Ubuntu 18.04/21.04 on local arm64/Apple Silicon): debian-11, debian-10, debian-9, ubuntu-21.04, ubuntu-20.04, ubuntu-18.04
+ARG VARIANT="bullseye"
+FROM mcr.microsoft.com/vscode/devcontainers/cpp:0-${VARIANT}
+
+# [Optional] Uncomment this section to install additional packages.
+# RUN apt-get update && export DEBIAN_FRONTEND=noninteractive \
+#     && apt-get -y install --no-install-recommends <your-package-list-here>
diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
new file mode 100644
index 0000000000..9b752d091d
--- /dev/null
+++ b/.devcontainer/devcontainer.json
@@ -0,0 +1,32 @@
+// For format details, see https://aka.ms/devcontainer.json. For config options, see the README at:
+// https://github.com/microsoft/vscode-dev-containers/tree/v0.209.3/containers/cpp
+{
+	"name": "C++",
+	"build": {
+		"dockerfile": "Dockerfile",
+		// Update 'VARIANT' to pick an Debian / Ubuntu OS version: debian-11, debian-10, debian-9, ubuntu-21.04, ubuntu-20.04, ubuntu-18.04
+		// Use Debian 11, Debian 9, Ubuntu 18.04 or Ubuntu 21.04 on local arm64/Apple Silicon
+		"args": { "VARIANT": "ubuntu-21.04" }
+	},
+	"runArgs": ["--cap-add=SYS_PTRACE", "--security-opt", "seccomp=unconfined"],
+
+	// Set *default* container specific settings.json values on container create.
+	"settings": {},
+
+	// Add the IDs of extensions you want installed when the container is created.
+	"extensions": [
+		"ms-vscode.cpptools",
+		"ms-vscode.cmake-tools",
+		"austin.code-gnu-global",
+		"visualstudioexptteam.vscodeintel"
+	],
+
+	// Use 'forwardPorts' to make a list of ports inside the container available locally.
+	// "forwardPorts": [],
+
+	// Use 'postCreateCommand' to run commands after the container is created.
+	// "postCreateCommand": "gcc -v",
+
+	// Comment out connect as root instead. More info: https://aka.ms/vscode-remote/containers/non-root.
+	"remoteUser": "vscode"
+}
diff --git a/.gitignore b/.gitignore
index c651127992..2308ea7896 100644
--- a/.gitignore
+++ b/.gitignore
@@ -101,4 +101,4 @@ TAGS
 
 contrib/*
 !contrib/CMakeLists.txt
-!contrib/test
+!contrib/test
\ No newline at end of file
diff --git a/CMakeLists.txt b/CMakeLists.txt
index b626977588..1a8cb1d710 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -10,7 +10,7 @@ set(CMAKE_SUPPORT_DIR "${CMAKE_SOURCE_DIR}/cmake")
 set(CMAKE_CONTRIB_DIR "${CMAKE_SOURCE_DIR}/contrib")
 include(${CMAKE_SUPPORT_DIR}/cmake.options)
 
-SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fPIC -gdwarf-2 -msse4.2 -mfma")
+SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fPIC -gdwarf-2 -msse4.2 -mfma -g3")
 
 # contrib
 add_subdirectory(contrib)
@@ -20,9 +20,13 @@ add_library(api INTERFACE)
 target_include_directories(api INTERFACE "include/client")
 
 # src
+if(${BUILD_TEST})
+    include(CTest)
+    enable_testing()
+endif(${BUILD_TEST})
 add_subdirectory(source)
 
 # docs 
 add_subdirectory(docs)
 
-# tests (TODO)
+# tests (TODO)
\ No newline at end of file
diff --git a/include/dnode/vnode/tq/tq.h b/include/dnode/vnode/tq/tq.h
index 85533f65bc..7359df92cc 100644
--- a/include/dnode/vnode/tq/tq.h
+++ b/include/dnode/vnode/tq/tq.h
@@ -256,7 +256,7 @@ typedef struct STQ {
   // the collection of group handle
   // the handle of kvstore
   char*  path;
-  STqCfg*    tqConfig;
+  STqCfg*      tqConfig;
   TqLogReader* tqLogReader; 
   TqMemRef     tqMemRef;
   TqMetaStore* tqMeta;
diff --git a/include/dnode/vnode/vnode.h b/include/dnode/vnode/vnode.h
index 30531ad738..007ce83812 100644
--- a/include/dnode/vnode/vnode.h
+++ b/include/dnode/vnode/vnode.h
@@ -36,6 +36,8 @@ typedef struct SVnodeCfg {
   struct {
     /** write buffer size */
     uint64_t wsize;
+    uint64_t ssize;
+    uint64_t lsize;
     /** use heap allocator or arena allocator */
     bool isHeapAllocator;
   };
diff --git a/include/libs/wal/wal.h b/include/libs/wal/wal.h
index 48c775292a..ae1e630c6f 100644
--- a/include/libs/wal/wal.h
+++ b/include/libs/wal/wal.h
@@ -44,7 +44,7 @@ typedef struct SWalReadHead {
   int8_t   reserved[2];
   int32_t  len;
   int64_t  version;
-  char     cont[];
+  char     body[];
 } SWalReadHead;
 
 typedef struct {
@@ -52,9 +52,9 @@ typedef struct {
   int32_t  fsyncPeriod;      // millisecond
   int32_t  retentionPeriod;  // secs
   int32_t  rollPeriod;       // secs
-  int32_t  retentionSize;       // secs
+  int64_t  retentionSize;
   int64_t  segSize;
-  EWalType walLevel;         // wal level
+  EWalType level;         // wal level
 } SWalCfg;
 
 typedef struct {
@@ -90,15 +90,17 @@ typedef struct {
 #define WAL_CUR_FILE_WRITABLE 2
 #define WAL_CUR_FAILED        4
 
+typedef struct SWalVer {
+  int64_t firstVer;
+  int64_t verInSnapshotting;
+  int64_t snapshotVer;
+  int64_t commitVer;
+  int64_t lastVer;
+} SWalVer;
+
 typedef struct SWal {
   // cfg
-  int32_t  vgId;
-  int32_t  fsyncPeriod;  // millisecond
-  int32_t  rollPeriod;  // second
-  int64_t  segSize;
-  int64_t  retentionSize;
-  int32_t  retentionPeriod;
-  EWalType level;
+  SWalCfg cfg;
   //total size
   int64_t  totSize;
   //fsync seq
@@ -109,12 +111,7 @@ typedef struct SWal {
   int64_t writeLogTfd;
   int64_t writeIdxTfd;
   //wal lifecycle
-  int64_t firstVersion;
-  int64_t snapshotVersion;
-  int64_t commitVersion;
-  int64_t lastVersion;
-  //snapshotting version
-  int64_t snapshottingVer;
+  SWalVer vers;
   //roll status
   int64_t lastRollSeq;
   //file set
@@ -126,9 +123,20 @@ typedef struct SWal {
   //path
   char path[WAL_PATH_LEN];
   //reusable write head
-  SWalHead head;
+  SWalHead writeHead;
 } SWal;  // WAL HANDLE
 
+typedef struct SWalReadHandle {
+  SWal*        pWal;
+  int64_t      readLogTfd;
+  int64_t      readIdxTfd;
+  int64_t      curFileFirstVer;
+  int64_t      curVersion;
+  int64_t      capacity;
+  int64_t      status;  //if cursor valid
+  SWalHead     head;
+} SWalReadHandle;
+
 typedef int32_t (*FWalWrite)(void *ahandle, void *pHead);
 
 // module initialization
@@ -154,6 +162,10 @@ int32_t walEndTakeSnapshot(SWal *);
 //int32_t  walDataCorrupted(SWal*);
 
 // read
+SWalReadHandle* walOpenReadHandle(SWal *);
+void    walCloseReadHandle(SWalReadHandle *);
+int32_t walReadWithHandle(SWalReadHandle *pRead, int64_t ver);
+
 int32_t walRead(SWal *, SWalHead **, int64_t ver);
 int32_t walReadWithFp(SWal *, FWalWrite writeFp, int64_t verStart, int32_t readNum);
 
diff --git a/include/util/tdlist.h b/include/util/tdlist.h
new file mode 100644
index 0000000000..a19f3bebec
--- /dev/null
+++ b/include/util/tdlist.h
@@ -0,0 +1,169 @@
+/*
+ * 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/>.
+ */
+
+#ifndef _TD_UTIL_TDLIST_H_
+#define _TD_UTIL_TDLIST_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Single linked list
+#define TD_SLIST_NODE(TYPE) \
+  struct {                  \
+    struct TYPE *sl_next_;  \
+  }
+
+#define TD_SLIST(TYPE)      \
+  struct {                  \
+    struct TYPE *sl_head_;  \
+    int          sl_neles_; \
+  }
+
+#define TD_SLIST_HEAD(sl) ((sl)->sl_head_)
+#define TD_SLIST_NELES(sl) ((sl)->sl_neles_)
+#define TD_SLIST_NODE_NEXT(sln) ((sln)->sl_next_)
+
+#define tSListInit(sl)     \
+  do {                     \
+    (sl)->sl_head_ = NULL; \
+    (sl)->sl_neles_ = 0;   \
+  } while (0)
+
+#define tSListPush(sl, sln)                      \
+  do {                                           \
+    TD_SLIST_NODE_NEXT(sln) = TD_SLIST_HEAD(sl); \
+    TD_SLIST_HEAD(sl) = (sln);                   \
+    TD_SLIST_NELES(sl) += 1;                     \
+  } while (0)
+
+#define tSListPop(sl)                                          \
+  do {                                                         \
+    TD_SLIST_HEAD(sl) = TD_SLIST_NODE_NEXT(TD_SLIST_HEAD(sl)); \
+    TD_SLIST_NELES(sl) -= 1;                                   \
+  } while (0)
+
+// Double linked list
+#define TD_DLIST_NODE(TYPE) \
+  struct {                  \
+    TYPE *dl_prev_;         \
+    TYPE *dl_next_;         \
+  }
+
+#define TD_DLIST(TYPE)      \
+  struct {                  \
+    struct TYPE *dl_head_;  \
+    struct TYPE *dl_tail_;  \
+    int          dl_neles_; \
+  }
+
+#define TD_DLIST_NODE_PREV(dln) ((dln)->dl_prev_)
+#define TD_DLIST_NODE_NEXT(dln) ((dln)->dl_next_)
+#define TD_DLIST_HEAD(dl) ((dl)->dl_head_)
+#define TD_DLIST_TAIL(dl) ((dl)->dl_tail_)
+#define TD_DLIST_NELES(dl) ((dl)->dl_neles_)
+
+#define tDListInit(dl)                            \
+  do {                                            \
+    TD_DLIST_HEAD(dl) = TD_DLIST_TAIL(dl) = NULL; \
+    TD_DLIST_NELES(dl) = 0;                       \
+  } while (0)
+
+#define tDListAppend(dl, dln)                                   \
+  do {                                                          \
+    if (TD_DLIST_HEAD(dl) == NULL) {                            \
+      TD_DLIST_NODE_PREV(dln) = TD_DLIST_NODE_NEXT(dln) = NULL; \
+      TD_DLIST_HEAD(dl) = TD_DLIST_TAIL(dl) = (dln);            \
+    } else {                                                    \
+      TD_DLIST_NODE_PREV(dln) = TD_DLIST_TAIL(dl);              \
+      TD_DLIST_NODE_NEXT(dln) = NULL;                           \
+      TD_DLIST_NODE_NEXT(TD_DLIST_TAIL(dl)) = (dln);            \
+      TD_DLIST_TAIL(dl) = (dln);                                \
+    }                                                           \
+    TD_DLIST_NELES(dl) += 1;                                    \
+  } while (0)
+
+#define tDListPrepend(dl, dln)                                  \
+  do {                                                          \
+    if (TD_DLIST_HEAD(dl) == NULL) {                            \
+      TD_DLIST_NODE_PREV(dln) = TD_DLIST_NODE_NEXT(dln) = NULL; \
+      TD_DLIST_HEAD(dl) = TD_DLIST_TAIL(dl) = (dln);            \
+    } else {                                                    \
+      TD_DLIST_NODE_PREV(dln) = NULL;                           \
+      TD_DLIST_NODE_NEXT(dln) = TD_DLIST_HEAD(dl);              \
+      TD_DLIST_NODE_PREV(TD_DLIST_HEAD(dl)) = (dln);            \
+      TD_DLIST_HEAD(dl) = (dln);                                \
+    }                                                           \
+    TD_DLIST_NELES(dl) += 1;                                    \
+  } while (0)
+
+#define tDListPop(dl, dln)                                                   \
+  do {                                                                       \
+    if (TD_DLIST_HEAD(dl) == (dln)) {                                        \
+      TD_DLIST_HEAD(dl) = TD_DLIST_NODE_NEXT(dln);                           \
+    }                                                                        \
+    if (TD_DLIST_TAIL(dl) == (dln)) {                                        \
+      TD_DLIST_TAIL(dl) = TD_DLIST_NODE_PREV(dln);                           \
+    }                                                                        \
+    if (TD_DLIST_NODE_PREV(dln) != NULL) {                                   \
+      TD_DLIST_NODE_NEXT(TD_DLIST_NODE_PREV(dln)) = TD_DLIST_NODE_NEXT(dln); \
+    }                                                                        \
+    if (TD_DLIST_NODE_NEXT(dln) != NULL) {                                   \
+      TD_DLIST_NODE_PREV(TD_DLIST_NODE_NEXT(dln)) = TD_DLIST_NODE_PREV(dln); \
+    }                                                                        \
+    TD_DLIST_NELES(dl) -= 1;                                                 \
+    TD_DLIST_NODE_PREV(dln) = TD_DLIST_NODE_NEXT(dln) = NULL;                \
+  } while (0)
+
+#if 0
+// List iterator
+#define TD_LIST_FITER 0
+#define TD_LIST_BITER 1
+#define TD_LIST_ITER(S)     \
+  struct {                  \
+    int it_dir_;            \
+    S * it_next_;           \
+    S * it_ptr_;            \
+    TD_DLIST(S) * it_list_; \
+  }
+
+#define tlistIterInit(it, l, dir)   \
+  (it)->it_dir_ = (dir);            \
+  (it)->it_list_ = l;               \
+  if ((dir) == TD_LIST_FITER) {     \
+    (it)->it_next_ = (l)->dl_head_; \
+  } else {                          \
+    (it)->it_next_ = (l)->dl_tail_; \
+  }
+
+#define tlistIterNext(it)                       \
+  ({                                            \
+    (it)->it_ptr_ = (it)->it_next_;             \
+    if ((it)->it_next_ != NULL) {               \
+      if ((it)->it_dir_ == TD_LIST_FITER) {     \
+        (it)->it_next_ = (it)->it_next_->next_; \
+      } else {                                  \
+        (it)->it_next_ = (it)->it_next_->prev_; \
+      }                                         \
+    }                                           \
+    (it)->it_ptr_;                              \
+  })
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /*_TD_UTIL_TDLIST_H_*/
\ No newline at end of file
diff --git a/include/util/tmacro.h b/include/util/tmacro.h
new file mode 100644
index 0000000000..74056cfe07
--- /dev/null
+++ b/include/util/tmacro.h
@@ -0,0 +1,44 @@
+/*
+ * 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/>.
+ */
+
+#ifndef _TD_UTIL_MACRO_H_
+#define _TD_UTIL_MACRO_H_
+
+#include "os.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Module init/clear MACRO definitions
+#define TD_MOD_UNINITIALIZED 0
+#define TD_MOD_INITIALIZED 1
+
+#define TD_MOD_UNCLEARD 0
+#define TD_MOD_CLEARD 1
+
+#define TD_DEF_MOD_INIT_FLAG(MOD) static int8_t MOD##InitFlag = TD_MOD_UNINITIALIZED
+#define TD_DEF_MOD_CLEAR_FLAG(MOD) static int8_t MOD##ClearFlag = TD_MOD_UNCLEARD
+
+#define TD_CHECK_AND_SET_MODE_INIT(MOD) \
+  atomic_val_compare_exchange_8(&(MOD##InitFlag), TD_MOD_UNINITIALIZED, TD_MOD_INITIALIZED)
+
+#define TD_CHECK_AND_SET_MOD_CLEAR(MOD) atomic_val_compare_exchange_8(&(MOD##ClearFlag), TD_MOD_UNCLEARD, TD_MOD_CLEARD)
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /*_TD_UTIL_MACRO_H_*/
\ No newline at end of file
diff --git a/source/dnode/mgmt/impl/test/dnode/dnode.cpp b/source/dnode/mgmt/impl/test/dnode/dnode.cpp
index c156852905..fba3794f6a 100644
--- a/source/dnode/mgmt/impl/test/dnode/dnode.cpp
+++ b/source/dnode/mgmt/impl/test/dnode/dnode.cpp
@@ -271,7 +271,6 @@ TEST_F(DndTestDnode, DropDnode_01) {
   ASSERT_NE(pMsg, nullptr);
   ASSERT_EQ(pMsg->code, 0);
 
-  taosMsleep(1300);
   SendTheCheckShowMetaMsg(TSDB_MGMT_TABLE_DNODE, "show dnodes", 7);
   SendThenCheckShowRetrieveMsg(1);
   CheckInt16(1);
@@ -363,7 +362,7 @@ TEST_F(DndTestDnode, CreateDnode_02) {
 }
 
 TEST_F(DndTestDnode, RestartDnode_01) {
-  uInfo("===> stop all server");
+  uInfo("stop all server");
   stopServer(pServer1);
   stopServer(pServer2);
   stopServer(pServer3);
@@ -375,14 +374,16 @@ TEST_F(DndTestDnode, RestartDnode_01) {
   pServer4 = NULL;
   pServer5 = NULL;
 
-  taosMsleep(3000);  // wait tcp port cleanedup
-  uInfo("===> start all server");
+  uInfo("start all server");
 
   const char* fqdn = "localhost";
   const char* firstEp = "localhost:9521";
   pServer1 = startServer("/tmp/dndTestDnode1", fqdn, 9521, firstEp);
+  // pServer1 = startServer("/tmp/dndTestDnode3", fqdn, 9523, firstEp);
+  // pServer1 = startServer("/tmp/dndTestDnode4", fqdn, 9524, firstEp);
+  // pServer1 = startServer("/tmp/dndTestDnode5", fqdn, 9525, firstEp);
 
-  uInfo("===> all server is running");
+  uInfo("all server is running");
 
   // taosMsleep(1300);
   // SendTheCheckShowMetaMsg(TSDB_MGMT_TABLE_DNODE, "show dnodes", 7);
diff --git a/source/dnode/mgmt/impl/test/user/user.cpp b/source/dnode/mgmt/impl/test/user/user.cpp
index c3c1d1d406..48be2635cd 100644
--- a/source/dnode/mgmt/impl/test/user/user.cpp
+++ b/source/dnode/mgmt/impl/test/user/user.cpp
@@ -17,270 +17,223 @@
 
 class DndTestUser : public ::testing::Test {
  protected:
-  void SetUp() override {}
-  void TearDown() override {}
+  static SServer* CreateServer(const char* path, const char* fqdn, uint16_t port, const char* firstEp) {
+    SServer* pServer = createServer(path, fqdn, port, firstEp);
+    ASSERT(pServer);
+    return pServer;
+  }
 
   static void SetUpTestSuite() {
-    const char* user = "root";
-    const char* pass = "taosdata";
-    const char* path = "/tmp/dndTestUser";
-    const char* fqdn = "localhost";
-    uint16_t    port = 9524;
-    const char* firstEp = "localhost:9524";
+    initLog("/tmp/dndTestUser");
 
-    pServer = createServer(path, fqdn, port, firstEp);
-    ASSERT(pServer);
-    pClient = createClient(user, pass, fqdn, port);
+    const char* fqdn = "localhost";
+    const char* firstEp = "localhost:9530";
+    pServer = CreateServer("/tmp/dndTestUser", fqdn, 9530, firstEp);
+    pClient = createClient("root", "taosdata", fqdn, 9530);
+    taosMsleep(300);
   }
 
   static void TearDownTestSuite() {
     stopServer(pServer);
     dropClient(pClient);
+    pServer = NULL;
+    pClient = NULL;
   }
 
   static SServer* pServer;
   static SClient* pClient;
   static int32_t  connId;
+
+ public:
+  void SetUp() override {}
+  void TearDown() override {}
+
+  void SendTheCheckShowMetaMsg(int8_t showType, const char* showName, int32_t columns) {
+    SShowMsg* pShow = (SShowMsg*)rpcMallocCont(sizeof(SShowMsg));
+    pShow->type = showType;
+    strcpy(pShow->db, "");
+
+    SRpcMsg showRpcMsg = {0};
+    showRpcMsg.pCont = pShow;
+    showRpcMsg.contLen = sizeof(SShowMsg);
+    showRpcMsg.msgType = TSDB_MSG_TYPE_SHOW;
+
+    sendMsg(pClient, &showRpcMsg);
+    ASSERT_NE(pClient->pRsp, nullptr);
+    ASSERT_EQ(pClient->pRsp->code, 0);
+    ASSERT_NE(pClient->pRsp->pCont, nullptr);
+
+    SShowRsp* pShowRsp = (SShowRsp*)pClient->pRsp->pCont;
+    ASSERT_NE(pShowRsp, nullptr);
+    pShowRsp->showId = htonl(pShowRsp->showId);
+    pMeta = &pShowRsp->tableMeta;
+    pMeta->numOfTags = htons(pMeta->numOfTags);
+    pMeta->numOfColumns = htons(pMeta->numOfColumns);
+    pMeta->sversion = htons(pMeta->sversion);
+    pMeta->tversion = htons(pMeta->tversion);
+    pMeta->tuid = htobe64(pMeta->tuid);
+    pMeta->suid = htobe64(pMeta->suid);
+
+    showId = pShowRsp->showId;
+
+    EXPECT_NE(pShowRsp->showId, 0);
+    EXPECT_STREQ(pMeta->tbFname, showName);
+    EXPECT_EQ(pMeta->numOfTags, 0);
+    EXPECT_EQ(pMeta->numOfColumns, columns);
+    EXPECT_EQ(pMeta->precision, 0);
+    EXPECT_EQ(pMeta->tableType, 0);
+    EXPECT_EQ(pMeta->update, 0);
+    EXPECT_EQ(pMeta->sversion, 0);
+    EXPECT_EQ(pMeta->tversion, 0);
+    EXPECT_EQ(pMeta->tuid, 0);
+    EXPECT_EQ(pMeta->suid, 0);
+  }
+
+  void CheckSchema(int32_t index, int8_t type, int32_t bytes, const char* name) {
+    SSchema* pSchema = &pMeta->pSchema[index];
+    pSchema->bytes = htons(pSchema->bytes);
+    EXPECT_EQ(pSchema->colId, 0);
+    EXPECT_EQ(pSchema->type, type);
+    EXPECT_EQ(pSchema->bytes, bytes);
+    EXPECT_STREQ(pSchema->name, name);
+  }
+
+  void SendThenCheckShowRetrieveMsg(int32_t rows) {
+    SRetrieveTableMsg* pRetrieve = (SRetrieveTableMsg*)rpcMallocCont(sizeof(SRetrieveTableMsg));
+    pRetrieve->showId = htonl(showId);
+    pRetrieve->free = 0;
+
+    SRpcMsg retrieveRpcMsg = {0};
+    retrieveRpcMsg.pCont = pRetrieve;
+    retrieveRpcMsg.contLen = sizeof(SRetrieveTableMsg);
+    retrieveRpcMsg.msgType = TSDB_MSG_TYPE_SHOW_RETRIEVE;
+
+    sendMsg(pClient, &retrieveRpcMsg);
+
+    ASSERT_NE(pClient->pRsp, nullptr);
+    ASSERT_EQ(pClient->pRsp->code, 0);
+    ASSERT_NE(pClient->pRsp->pCont, nullptr);
+
+    pRetrieveRsp = (SRetrieveTableRsp*)pClient->pRsp->pCont;
+    ASSERT_NE(pRetrieveRsp, nullptr);
+    pRetrieveRsp->numOfRows = htonl(pRetrieveRsp->numOfRows);
+    pRetrieveRsp->offset = htobe64(pRetrieveRsp->offset);
+    pRetrieveRsp->useconds = htobe64(pRetrieveRsp->useconds);
+    pRetrieveRsp->compLen = htonl(pRetrieveRsp->compLen);
+
+    EXPECT_EQ(pRetrieveRsp->numOfRows, rows);
+    EXPECT_EQ(pRetrieveRsp->offset, 0);
+    EXPECT_EQ(pRetrieveRsp->useconds, 0);
+    // EXPECT_EQ(pRetrieveRsp->completed, completed);
+    EXPECT_EQ(pRetrieveRsp->precision, TSDB_TIME_PRECISION_MILLI);
+    EXPECT_EQ(pRetrieveRsp->compressed, 0);
+    EXPECT_EQ(pRetrieveRsp->reserved, 0);
+    EXPECT_EQ(pRetrieveRsp->compLen, 0);
+
+    pData = pRetrieveRsp->data;
+    pos = 0;
+  }
+
+  void CheckInt16(int16_t val) {
+    int16_t data = *((int16_t*)(pData + pos));
+    pos += sizeof(int16_t);
+    EXPECT_EQ(data, val);
+  }
+
+  void CheckInt64(int64_t val) {
+    int64_t data = *((int64_t*)(pData + pos));
+    pos += sizeof(int64_t);
+    EXPECT_EQ(data, val);
+  }
+
+  void CheckTimestamp() {
+    int64_t data = *((int64_t*)(pData + pos));
+    pos += sizeof(int64_t);
+    EXPECT_GT(data, 0);
+  }
+
+  void CheckBinary(const char* val, int32_t len) {
+    pos += sizeof(VarDataLenT);
+    char* data = (char*)(pData + pos);
+    pos += len;
+    EXPECT_STREQ(data, val);
+  }
+
+  int32_t            showId;
+  STableMetaMsg*     pMeta;
+  SRetrieveTableRsp* pRetrieveRsp;
+  char*              pData;
+  int32_t            pos;
 };
 
 SServer* DndTestUser::pServer;
 SClient* DndTestUser::pClient;
 int32_t  DndTestUser::connId;
 
-#if 0
 TEST_F(DndTestUser, ShowUser) {
-  int32_t showId = 0;
+  SendTheCheckShowMetaMsg(TSDB_MGMT_TABLE_USER, "show users", 4);
+  CheckSchema(0, TSDB_DATA_TYPE_BINARY, TSDB_USER_LEN + VARSTR_HEADER_SIZE, "name");
+  CheckSchema(1, TSDB_DATA_TYPE_BINARY, 10 + VARSTR_HEADER_SIZE, "privilege");
+  CheckSchema(2, TSDB_DATA_TYPE_TIMESTAMP, 8, "create time");
+  CheckSchema(3, TSDB_DATA_TYPE_BINARY, TSDB_USER_LEN + VARSTR_HEADER_SIZE, "account");
 
-  //--- meta ---
-  SShowMsg* pShow = (SShowMsg*)rpcMallocCont(sizeof(SShowMsg));
-  pShow->type = TSDB_MGMT_TABLE_USER;
-  strcpy(pShow->db, "");
-
-  SRpcMsg showRpcMsg = {0};
-  showRpcMsg.pCont = pShow;
-  showRpcMsg.contLen = sizeof(SShowMsg);
-  showRpcMsg.msgType = TSDB_MSG_TYPE_SHOW;
-
-  sendMsg(pClient, &showRpcMsg);
-  ASSERT_NE(pClient->pRsp, nullptr);
-
-  SShowRsp* pShowRsp = (SShowRsp*)pClient->pRsp->pCont;
-  ASSERT_NE(pShowRsp, nullptr);
-  pShowRsp->showId = htonl(pShowRsp->showId);
-  STableMetaMsg* pMeta = &pShowRsp->tableMeta;
-  pMeta->contLen = htonl(pMeta->contLen);
-  pMeta->numOfColumns = htons(pMeta->numOfColumns);
-  pMeta->sversion = htons(pMeta->sversion);
-  pMeta->tversion = htons(pMeta->tversion);
-  pMeta->tid = htonl(pMeta->tid);
-  pMeta->uid = htobe64(pMeta->uid);
-  pMeta->suid = htobe64(pMeta->suid);
-
-  showId = pShowRsp->showId;
-
-  EXPECT_NE(pShowRsp->showId, 0);
-  EXPECT_EQ(pMeta->contLen, 0);
-  EXPECT_STREQ(pMeta->tbFname, "show users");
-  EXPECT_EQ(pMeta->numOfTags, 0);
-  EXPECT_EQ(pMeta->precision, 0);
-  EXPECT_EQ(pMeta->tableType, 0);
-  EXPECT_EQ(pMeta->numOfColumns, 4);
-  EXPECT_EQ(pMeta->sversion, 0);
-  EXPECT_EQ(pMeta->tversion, 0);
-  EXPECT_EQ(pMeta->tid, 0);
-  EXPECT_EQ(pMeta->uid, 0);
-  EXPECT_STREQ(pMeta->sTableName, "");
-  EXPECT_EQ(pMeta->suid, 0);
-
-  SSchema* pSchema = NULL;
-
-  pSchema = &pMeta->pSchema[0];
-  pSchema->bytes = htons(pSchema->bytes);
-  EXPECT_EQ(pSchema->colId, 0);
-  EXPECT_EQ(pSchema->type, TSDB_DATA_TYPE_BINARY);
-  EXPECT_EQ(pSchema->bytes, TSDB_USER_LEN + VARSTR_HEADER_SIZE);
-  EXPECT_STREQ(pSchema->name, "name");
-
-  pSchema = &pMeta->pSchema[1];
-  pSchema->bytes = htons(pSchema->bytes);
-  EXPECT_EQ(pSchema->colId, 0);
-  EXPECT_EQ(pSchema->type, TSDB_DATA_TYPE_BINARY);
-  EXPECT_EQ(pSchema->bytes, 10 + VARSTR_HEADER_SIZE);
-  EXPECT_STREQ(pSchema->name, "privilege");
-
-  pSchema = &pMeta->pSchema[2];
-  pSchema->bytes = htons(pSchema->bytes);
-  EXPECT_EQ(pSchema->colId, 0);
-  EXPECT_EQ(pSchema->type, TSDB_DATA_TYPE_TIMESTAMP);
-  EXPECT_EQ(pSchema->bytes, 8);
-  EXPECT_STREQ(pSchema->name, "create_time");
-
-  pSchema = &pMeta->pSchema[3];
-  pSchema->bytes = htons(pSchema->bytes);
-  EXPECT_EQ(pSchema->colId, 0);
-  EXPECT_EQ(pSchema->type, TSDB_DATA_TYPE_BINARY);
-  EXPECT_EQ(pSchema->bytes, TSDB_USER_LEN + VARSTR_HEADER_SIZE);
-  EXPECT_STREQ(pSchema->name, "account");
-
-  //--- retrieve ---
-  SRetrieveTableMsg* pRetrieve = (SRetrieveTableMsg*)rpcMallocCont(sizeof(SRetrieveTableMsg));
-  pRetrieve->showId = htonl(showId);
-  pRetrieve->free = 0;
-
-  SRpcMsg retrieveRpcMsg = {0};
-  retrieveRpcMsg.pCont = pRetrieve;
-  retrieveRpcMsg.contLen = sizeof(SRetrieveTableMsg);
-  retrieveRpcMsg.msgType = TSDB_MSG_TYPE_SHOW_RETRIEVE;
-
-  sendMsg(pClient, &retrieveRpcMsg);
-  ASSERT_NE(pClient->pRsp, nullptr);
-  ASSERT_EQ(pClient->pRsp->code, 0);
-
-  SRetrieveTableRsp* pRetrieveRsp = (SRetrieveTableRsp*)pClient->pRsp->pCont;
-  ASSERT_NE(pRetrieveRsp, nullptr);
-  pRetrieveRsp->numOfRows = htonl(pRetrieveRsp->numOfRows);
-  pRetrieveRsp->offset = htobe64(pRetrieveRsp->offset);
-  pRetrieveRsp->useconds = htobe64(pRetrieveRsp->useconds);
-  pRetrieveRsp->compLen = htonl(pRetrieveRsp->compLen);
-
-  EXPECT_EQ(pRetrieveRsp->numOfRows, 2);
-  EXPECT_EQ(pRetrieveRsp->offset, 0);
-  EXPECT_EQ(pRetrieveRsp->useconds, 0);
-  EXPECT_EQ(pRetrieveRsp->completed, 1);
-  EXPECT_EQ(pRetrieveRsp->precision, TSDB_TIME_PRECISION_MILLI);
-  EXPECT_EQ(pRetrieveRsp->compressed, 0);
-  EXPECT_EQ(pRetrieveRsp->reserved, 0);
-  EXPECT_EQ(pRetrieveRsp->compLen, 0);
-
-  char*   pData = pRetrieveRsp->data;
-  int32_t pos = 0;
-  char*   strVal = NULL;
-  int64_t int64Val = 0;
-
-  //--- name ---
-  {
-    pos += sizeof(VarDataLenT);
-    strVal = (char*)(pData + pos);
-    pos += TSDB_USER_LEN;
-    EXPECT_STREQ(strVal, "root");
-
-    pos += sizeof(VarDataLenT);
-    strVal = (char*)(pData + pos);
-    pos += TSDB_USER_LEN;
-    EXPECT_STREQ(strVal, "_root");
-  }
-
-  //--- privilege ---
-  {
-    pos += sizeof(VarDataLenT);
-    strVal = (char*)(pData + pos);
-    pos += 10;
-    EXPECT_STREQ(strVal, "super");
-
-    pos += sizeof(VarDataLenT);
-    strVal = (char*)(pData + pos);
-    pos += 10;
-    EXPECT_STREQ(strVal, "writable");
-  }
-
-  //--- create_time ---
-  {
-    int64Val = *((int64_t*)(pData + pos));
-    pos += sizeof(int64_t);
-    EXPECT_GT(int64Val, 0);
-
-    int64Val = *((int64_t*)(pData + pos));
-    pos += sizeof(int64_t);
-    EXPECT_GT(int64Val, 0);
-  }
-
-  //--- account ---
-  {
-    pos += sizeof(VarDataLenT);
-    strVal = (char*)(pData + pos);
-    pos += TSDB_USER_LEN;
-    EXPECT_STREQ(strVal, "root");
-
-    pos += sizeof(VarDataLenT);
-    strVal = (char*)(pData + pos);
-    pos += TSDB_USER_LEN;
-    EXPECT_STREQ(strVal, "root");
-  }
+  SendThenCheckShowRetrieveMsg(1);
+  CheckBinary("root", TSDB_USER_LEN);
+  CheckBinary("super", 10);
+  CheckTimestamp();
+  CheckBinary("root", TSDB_USER_LEN);
 }
-#endif
 
 TEST_F(DndTestUser, CreateUser_01) {
-  ASSERT_NE(pClient, nullptr);
-
-  //--- create user ---
-  SCreateUserMsg* pReq = (SCreateUserMsg*)rpcMallocCont(sizeof(SCreateUserMsg));
-  strcpy(pReq->user, "u1");
-  strcpy(pReq->pass, "p1");
-
-  SRpcMsg rpcMsg = {0};
-  rpcMsg.pCont = pReq;
-  rpcMsg.contLen = sizeof(SCreateUserMsg);
-  rpcMsg.msgType = TSDB_MSG_TYPE_CREATE_USER;
-
-  sendMsg(pClient, &rpcMsg);
-  SRpcMsg* pMsg = pClient->pRsp;
-  ASSERT_NE(pMsg, nullptr);
-  ASSERT_EQ(pMsg->code, 0);
-
-  //--- meta ---
-  SShowMsg* pShow = (SShowMsg*)rpcMallocCont(sizeof(SShowMsg));
-  pShow->type = TSDB_MGMT_TABLE_USER;
-  SRpcMsg showRpcMsg = {0};
-  showRpcMsg.pCont = pShow;
-  showRpcMsg.contLen = sizeof(SShowMsg);
-  showRpcMsg.msgType = TSDB_MSG_TYPE_SHOW;
-
-  sendMsg(pClient, &showRpcMsg);
-  SShowRsp*      pShowRsp = (SShowRsp*)pClient->pRsp->pCont;
-  STableMetaMsg* pMeta = &pShowRsp->tableMeta;
-  pMeta->numOfColumns = htons(pMeta->numOfColumns);
-  EXPECT_EQ(pMeta->numOfColumns, 4);
-
-  //--- retrieve ---
-  SRetrieveTableMsg* pRetrieve = (SRetrieveTableMsg*)rpcMallocCont(sizeof(SRetrieveTableMsg));
-  pRetrieve->showId = pShowRsp->showId;
-  SRpcMsg retrieveRpcMsg = {0};
-  retrieveRpcMsg.pCont = pRetrieve;
-  retrieveRpcMsg.contLen = sizeof(SRetrieveTableMsg);
-  retrieveRpcMsg.msgType = TSDB_MSG_TYPE_SHOW_RETRIEVE;
-
-  sendMsg(pClient, &retrieveRpcMsg);
-  SRetrieveTableRsp* pRetrieveRsp = (SRetrieveTableRsp*)pClient->pRsp->pCont;
-  pRetrieveRsp->numOfRows = htonl(pRetrieveRsp->numOfRows);
-  EXPECT_EQ(pRetrieveRsp->numOfRows, 3);
-
-  char*   pData = pRetrieveRsp->data;
-  int32_t pos = 0;
-  char*   strVal = NULL;
-
-  //--- name ---
   {
-    pos += sizeof(VarDataLenT);
-    strVal = (char*)(pData + pos);
-    pos += TSDB_USER_LEN;
-    EXPECT_STREQ(strVal, "u1");
+    SCreateUserMsg* pReq = (SCreateUserMsg*)rpcMallocCont(sizeof(SCreateUserMsg));
+    strcpy(pReq->user, "u1");
+    strcpy(pReq->pass, "p1");
 
-    pos += sizeof(VarDataLenT);
-    strVal = (char*)(pData + pos);
-    pos += TSDB_USER_LEN;
-    EXPECT_STREQ(strVal, "root");
+    SRpcMsg rpcMsg = {0};
+    rpcMsg.pCont = pReq;
+    rpcMsg.contLen = sizeof(SCreateUserMsg);
+    rpcMsg.msgType = TSDB_MSG_TYPE_CREATE_USER;
 
-    pos += sizeof(VarDataLenT);
-    strVal = (char*)(pData + pos);
-    pos += TSDB_USER_LEN;
-    EXPECT_STREQ(strVal, "_root");
+    sendMsg(pClient, &rpcMsg);
+    SRpcMsg* pMsg = pClient->pRsp;
+    ASSERT_NE(pMsg, nullptr);
+    ASSERT_EQ(pMsg->code, 0);
   }
+
+  {
+    SCreateUserMsg* pReq = (SCreateUserMsg*)rpcMallocCont(sizeof(SCreateUserMsg));
+    strcpy(pReq->user, "u2");
+    strcpy(pReq->pass, "p2");
+
+    SRpcMsg rpcMsg = {0};
+    rpcMsg.pCont = pReq;
+    rpcMsg.contLen = sizeof(SCreateUserMsg);
+    rpcMsg.msgType = TSDB_MSG_TYPE_CREATE_USER;
+
+    sendMsg(pClient, &rpcMsg);
+    SRpcMsg* pMsg = pClient->pRsp;
+    ASSERT_NE(pMsg, nullptr);
+    ASSERT_EQ(pMsg->code, 0);
+  }
+
+  SendTheCheckShowMetaMsg(TSDB_MGMT_TABLE_USER, "show users", 4);
+  SendThenCheckShowRetrieveMsg(3);
+  CheckBinary("u1", TSDB_USER_LEN);
+  CheckBinary("root", TSDB_USER_LEN);
+  CheckBinary("u2", TSDB_USER_LEN);
+  CheckBinary("normal", 10);
+  CheckBinary("super", 10);
+  CheckBinary("normal", 10);
+  CheckTimestamp();
+  CheckTimestamp();
+  CheckTimestamp();
+  CheckBinary("root", TSDB_USER_LEN);
+  CheckBinary("root", TSDB_USER_LEN);
+  CheckBinary("root", TSDB_USER_LEN);
 }
 
 TEST_F(DndTestUser, AlterUser_01) {
-  ASSERT_NE(pClient, nullptr);
-
-  //--- drop user ---
   SAlterUserMsg* pReq = (SAlterUserMsg*)rpcMallocCont(sizeof(SAlterUserMsg));
   strcpy(pReq->user, "u1");
   strcpy(pReq->pass, "p2");
@@ -295,60 +248,23 @@ TEST_F(DndTestUser, AlterUser_01) {
   ASSERT_NE(pMsg, nullptr);
   ASSERT_EQ(pMsg->code, 0);
 
-  //--- meta ---
-  SShowMsg* pShow = (SShowMsg*)rpcMallocCont(sizeof(SShowMsg));
-  pShow->type = TSDB_MGMT_TABLE_USER;
-  SRpcMsg showRpcMsg = {0};
-  showRpcMsg.pCont = pShow;
-  showRpcMsg.contLen = sizeof(SShowMsg);
-  showRpcMsg.msgType = TSDB_MSG_TYPE_SHOW;
-
-  sendMsg(pClient, &showRpcMsg);
-  SShowRsp*      pShowRsp = (SShowRsp*)pClient->pRsp->pCont;
-  STableMetaMsg* pMeta = &pShowRsp->tableMeta;
-  pMeta->numOfColumns = htons(pMeta->numOfColumns);
-  EXPECT_EQ(pMeta->numOfColumns, 4);
-
-  //--- retrieve ---
-  SRetrieveTableMsg* pRetrieve = (SRetrieveTableMsg*)rpcMallocCont(sizeof(SRetrieveTableMsg));
-  pRetrieve->showId = pShowRsp->showId;
-  SRpcMsg retrieveRpcMsg = {0};
-  retrieveRpcMsg.pCont = pRetrieve;
-  retrieveRpcMsg.contLen = sizeof(SRetrieveTableMsg);
-  retrieveRpcMsg.msgType = TSDB_MSG_TYPE_SHOW_RETRIEVE;
-
-  sendMsg(pClient, &retrieveRpcMsg);
-  SRetrieveTableRsp* pRetrieveRsp = (SRetrieveTableRsp*)pClient->pRsp->pCont;
-  pRetrieveRsp->numOfRows = htonl(pRetrieveRsp->numOfRows);
-  EXPECT_EQ(pRetrieveRsp->numOfRows, 3);
-
-  char*   pData = pRetrieveRsp->data;
-  int32_t pos = 0;
-  char*   strVal = NULL;
-
-  //--- name ---
-  {
-    pos += sizeof(VarDataLenT);
-    strVal = (char*)(pData + pos);
-    pos += TSDB_USER_LEN;
-    EXPECT_STREQ(strVal, "u1");
-
-    pos += sizeof(VarDataLenT);
-    strVal = (char*)(pData + pos);
-    pos += TSDB_USER_LEN;
-    EXPECT_STREQ(strVal, "root");
-
-    pos += sizeof(VarDataLenT);
-    strVal = (char*)(pData + pos);
-    pos += TSDB_USER_LEN;
-    EXPECT_STREQ(strVal, "_root");
-  }
+  SendTheCheckShowMetaMsg(TSDB_MGMT_TABLE_USER, "show users", 4);
+  SendThenCheckShowRetrieveMsg(3);
+  CheckBinary("u1", TSDB_USER_LEN);
+  CheckBinary("root", TSDB_USER_LEN);
+  CheckBinary("u2", TSDB_USER_LEN);
+  CheckBinary("normal", 10);
+  CheckBinary("super", 10);
+  CheckBinary("normal", 10);
+  CheckTimestamp();
+  CheckTimestamp();
+  CheckTimestamp();
+  CheckBinary("root", TSDB_USER_LEN);
+  CheckBinary("root", TSDB_USER_LEN);
+  CheckBinary("root", TSDB_USER_LEN);
 }
 
 TEST_F(DndTestUser, DropUser_01) {
-  ASSERT_NE(pClient, nullptr);
-
-  //--- drop user ---
   SDropUserMsg* pReq = (SDropUserMsg*)rpcMallocCont(sizeof(SDropUserMsg));
   strcpy(pReq->user, "u1");
 
@@ -362,47 +278,38 @@ TEST_F(DndTestUser, DropUser_01) {
   ASSERT_NE(pMsg, nullptr);
   ASSERT_EQ(pMsg->code, 0);
 
-  //--- meta ---
-  SShowMsg* pShow = (SShowMsg*)rpcMallocCont(sizeof(SShowMsg));
-  pShow->type = TSDB_MGMT_TABLE_USER;
-  SRpcMsg showRpcMsg = {0};
-  showRpcMsg.pCont = pShow;
-  showRpcMsg.contLen = sizeof(SShowMsg);
-  showRpcMsg.msgType = TSDB_MSG_TYPE_SHOW;
+  SendTheCheckShowMetaMsg(TSDB_MGMT_TABLE_USER, "show users", 4);
+  SendThenCheckShowRetrieveMsg(2);
+  CheckBinary("root", TSDB_USER_LEN);
+  CheckBinary("u2", TSDB_USER_LEN);
+  CheckBinary("super", 10);
+  CheckBinary("normal", 10);
+  CheckTimestamp();
+  CheckTimestamp();
+  CheckBinary("root", TSDB_USER_LEN);
+  CheckBinary("root", TSDB_USER_LEN);
+}
 
-  sendMsg(pClient, &showRpcMsg);
-  SShowRsp*      pShowRsp = (SShowRsp*)pClient->pRsp->pCont;
-  STableMetaMsg* pMeta = &pShowRsp->tableMeta;
-  pMeta->numOfColumns = htons(pMeta->numOfColumns);
-  EXPECT_EQ(pMeta->numOfColumns, 4);
+TEST_F(DndTestUser, RestartDnode) {
+  stopServer(pServer);
+  pServer = NULL;
 
-  //--- retrieve ---
-  SRetrieveTableMsg* pRetrieve = (SRetrieveTableMsg*)rpcMallocCont(sizeof(SRetrieveTableMsg));
-  pRetrieve->showId = pShowRsp->showId;
-  SRpcMsg retrieveRpcMsg = {0};
-  retrieveRpcMsg.pCont = pRetrieve;
-  retrieveRpcMsg.contLen = sizeof(SRetrieveTableMsg);
-  retrieveRpcMsg.msgType = TSDB_MSG_TYPE_SHOW_RETRIEVE;
+  uInfo("start all server");
 
-  sendMsg(pClient, &retrieveRpcMsg);
-  SRetrieveTableRsp* pRetrieveRsp = (SRetrieveTableRsp*)pClient->pRsp->pCont;
-  pRetrieveRsp->numOfRows = htonl(pRetrieveRsp->numOfRows);
-  EXPECT_EQ(pRetrieveRsp->numOfRows, 2);
+  const char* fqdn = "localhost";
+  const char* firstEp = "localhost:9530";
+  pServer = startServer("/tmp/dndTestUser", fqdn, 9530, firstEp);
 
-  char*   pData = pRetrieveRsp->data;
-  int32_t pos = 0;
-  char*   strVal = NULL;
+  uInfo("all server is running");
 
-  //--- name ---
-  {
-    pos += sizeof(VarDataLenT);
-    strVal = (char*)(pData + pos);
-    pos += TSDB_USER_LEN;
-    EXPECT_STREQ(strVal, "root");
-
-    pos += sizeof(VarDataLenT);
-    strVal = (char*)(pData + pos);
-    pos += TSDB_USER_LEN;
-    EXPECT_STREQ(strVal, "_root");
-  }
-}
\ No newline at end of file
+  SendTheCheckShowMetaMsg(TSDB_MGMT_TABLE_USER, "show users", 4);
+  SendThenCheckShowRetrieveMsg(2);
+  CheckBinary("root", TSDB_USER_LEN);
+  CheckBinary("u2", TSDB_USER_LEN);
+  CheckBinary("super", 10);
+  CheckBinary("normal", 10);
+  CheckTimestamp();
+  CheckTimestamp();
+  CheckBinary("root", TSDB_USER_LEN);
+  CheckBinary("root", TSDB_USER_LEN);
+}
diff --git a/source/dnode/mnode/impl/src/mndUser.c b/source/dnode/mnode/impl/src/mndUser.c
index 2e4719cceb..2f582a810d 100644
--- a/source/dnode/mnode/impl/src/mndUser.c
+++ b/source/dnode/mnode/impl/src/mndUser.c
@@ -85,9 +85,11 @@ static int32_t mndCreateDefaultUsers(SMnode *pMnode) {
     return -1;
   }
 
+#if 0
   if (mndCreateDefaultUser(pMnode, TSDB_DEFAULT_USER, "_" TSDB_DEFAULT_USER, TSDB_DEFAULT_PASS) != 0) {
     return -1;
   }
+#endif  
 
   return 0;
 }
@@ -469,7 +471,7 @@ static int32_t mndGetUserMeta(SMnodeMsg *pMsg, SShowObj *pShow, STableMetaMsg *p
 
   pShow->bytes[cols] = 8;
   pSchema[cols].type = TSDB_DATA_TYPE_TIMESTAMP;
-  strcpy(pSchema[cols].name, "create_time");
+  strcpy(pSchema[cols].name, "create time");
   pSchema[cols].bytes = htons(pShow->bytes[cols]);
   cols++;
 
@@ -516,11 +518,8 @@ static int32_t mndRetrieveUsers(SMnodeMsg *pMsg, SShowObj *pShow, char *data, in
     if (pUser->superAuth) {
       const char *src = "super";
       STR_WITH_SIZE_TO_VARSTR(pWrite, src, strlen(src));
-    } else if (pUser->writeAuth) {
-      const char *src = "writable";
-      STR_WITH_SIZE_TO_VARSTR(pWrite, src, strlen(src));
     } else {
-      const char *src = "readable";
+      const char *src = "normal";
       STR_WITH_SIZE_TO_VARSTR(pWrite, src, strlen(src));
     }
     cols++;
diff --git a/source/dnode/mnode/sdb/src/sdb.c b/source/dnode/mnode/sdb/src/sdb.c
index 1d4888c2eb..ccff5b6c82 100644
--- a/source/dnode/mnode/sdb/src/sdb.c
+++ b/source/dnode/mnode/sdb/src/sdb.c
@@ -52,10 +52,10 @@ SSdb *sdbInit(SSdbOpt *pOption) {
 void sdbCleanup(SSdb *pSdb) {
   mDebug("start to cleanup sdb");
 
-  if (pSdb->curVer != pSdb->lastCommitVer) {
+  // if (pSdb->curVer != pSdb->lastCommitVer) {
     mDebug("write sdb file for curVer:% " PRId64 " and lastVer:%" PRId64, pSdb->curVer, pSdb->lastCommitVer);
     sdbWriteFile(pSdb);
-  }
+  // }
 
   if (pSdb->currDir != NULL) {
     tfree(pSdb->currDir);
diff --git a/source/dnode/vnode/impl/CMakeLists.txt b/source/dnode/vnode/impl/CMakeLists.txt
index d6d267c4d4..6972605afd 100644
--- a/source/dnode/vnode/impl/CMakeLists.txt
+++ b/source/dnode/vnode/impl/CMakeLists.txt
@@ -18,6 +18,6 @@ target_link_libraries(
 )
 
 # test
-#if(${BUILD_TEST})
-#    add_subdirectory(test)
-#endif(${BUILD_TEST})
\ No newline at end of file
+if(${BUILD_TEST})
+   add_subdirectory(test)
+endif(${BUILD_TEST})
\ No newline at end of file
diff --git a/source/dnode/vnode/impl/inc/vnodeBufferPool.h b/source/dnode/vnode/impl/inc/vnodeBufferPool.h
index d64dc93847..bfc4de9e12 100644
--- a/source/dnode/vnode/impl/inc/vnodeBufferPool.h
+++ b/source/dnode/vnode/impl/inc/vnodeBufferPool.h
@@ -28,6 +28,7 @@ typedef struct SVBufPool SVBufPool;
 int   vnodeOpenBufPool(SVnode *pVnode);
 void  vnodeCloseBufPool(SVnode *pVnode);
 void *vnodeMalloc(SVnode *pVnode, uint64_t size);
+bool  vnodeBufPoolIsFull(SVnode *pVnode);
 
 #ifdef __cplusplus
 }
diff --git a/source/dnode/vnode/impl/inc/vnodeCommit.h b/source/dnode/vnode/impl/inc/vnodeCommit.h
index c8ff4947aa..a60e8feac2 100644
--- a/source/dnode/vnode/impl/inc/vnodeCommit.h
+++ b/source/dnode/vnode/impl/inc/vnodeCommit.h
@@ -22,8 +22,8 @@
 extern "C" {
 #endif
 
-bool vnodeShouldCommit(SVnode *pVnode);
-int  vnodeAsyncCommit(SVnode *pVnode);
+#define vnodeShouldCommit vnodeBufPoolIsFull
+int vnodeAsyncCommit(SVnode *pVnode);
 
 #ifdef __cplusplus
 }
diff --git a/source/dnode/vnode/impl/inc/vnodeDef.h b/source/dnode/vnode/impl/inc/vnodeDef.h
index c92de433c3..e3a3fac6b9 100644
--- a/source/dnode/vnode/impl/inc/vnodeDef.h
+++ b/source/dnode/vnode/impl/inc/vnodeDef.h
@@ -18,15 +18,17 @@
 
 #include "mallocator.h"
 #include "sync.h"
+#include "tcoding.h"
+#include "tdlist.h"
 #include "tlockfree.h"
 #include "wal.h"
-#include "tcoding.h"
 
 #include "vnode.h"
 #include "vnodeBufferPool.h"
 #include "vnodeCfg.h"
 #include "vnodeCommit.h"
 #include "vnodeFS.h"
+#include "vnodeMemAllocator.h"
 #include "vnodeRequest.h"
 #include "vnodeStateMgr.h"
 #include "vnodeSync.h"
diff --git a/source/dnode/vnode/impl/inc/vnodeMemAllocator.h b/source/dnode/vnode/impl/inc/vnodeMemAllocator.h
index 9184eb416b..c8c58e9f69 100644
--- a/source/dnode/vnode/impl/inc/vnodeMemAllocator.h
+++ b/source/dnode/vnode/impl/inc/vnodeMemAllocator.h
@@ -16,15 +16,37 @@
 #ifndef _TD_VNODE_MEM_ALLOCATOR_H_
 #define _TD_VNODE_MEM_ALLOCATOR_H_
 
-#include "mallocator.h"
-#include "vnode.h"
+#include "os.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-SMemAllocator *vnodeCreateMemAllocator(SVnode *pVnode);
-void           vnodeDestroyMemAllocator(SMemAllocator *pma);
+typedef struct SVArenaNode    SVArenaNode;
+typedef struct SVMemAllocator SVMemAllocator;
+
+struct SVArenaNode {
+  TD_SLIST_NODE(SVArenaNode);
+  uint64_t size;  // current node size
+  void *   ptr;
+  char     data[];
+};
+
+struct SVMemAllocator {
+  TD_DLIST_NODE(SVMemAllocator);
+  uint64_t     capacity;
+  uint64_t     ssize;
+  uint64_t     lsize;
+  SVArenaNode *pNode;
+  TD_SLIST(SVArenaNode) nlist;
+};
+
+SVMemAllocator *vmaCreate(uint64_t capacity, uint64_t ssize, uint64_t lsize);
+void            vmaDestroy(SVMemAllocator *pVMA);
+void            vmaReset(SVMemAllocator *pVMA);
+void *          vmaMalloc(SVMemAllocator *pVMA, uint64_t size);
+void            vmaFree(SVMemAllocator *pVMA, void *ptr);
+bool            vmaIsFull(SVMemAllocator *pVMA);
 
 #ifdef __cplusplus
 }
diff --git a/source/dnode/vnode/impl/src/vnodeArenaMAImpl.c b/source/dnode/vnode/impl/src/vnodeArenaMAImpl.c
new file mode 100644
index 0000000000..99d4781df9
--- /dev/null
+++ b/source/dnode/vnode/impl/src/vnodeArenaMAImpl.c
@@ -0,0 +1,117 @@
+/*
+ * 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/>.
+ */
+
+#include "vnodeDef.h"
+
+static SVArenaNode *vArenaNodeNew(uint64_t capacity);
+static void         vArenaNodeFree(SVArenaNode *pNode);
+
+SVMemAllocator *vmaCreate(uint64_t capacity, uint64_t ssize, uint64_t lsize) {
+  SVMemAllocator *pVMA = (SVMemAllocator *)malloc(sizeof(*pVMA));
+  if (pVMA == NULL) {
+    return NULL;
+  }
+
+  pVMA->capacity = capacity;
+  pVMA->ssize = ssize;
+  pVMA->lsize = lsize;
+  tSListInit(&(pVMA->nlist));
+
+  pVMA->pNode = vArenaNodeNew(capacity);
+  if (pVMA->pNode == NULL) {
+    free(pVMA);
+    return NULL;
+  }
+
+  tSListPush(&(pVMA->nlist), pVMA->pNode);
+
+  return pVMA;
+}
+
+void vmaDestroy(SVMemAllocator *pVMA) {
+  if (pVMA) {
+    while (TD_SLIST_NELES(&(pVMA->nlist)) > 1) {
+      SVArenaNode *pNode = TD_SLIST_HEAD(&(pVMA->nlist));
+      tSListPop(&(pVMA->nlist));
+      vArenaNodeFree(pNode);
+    }
+
+    free(pVMA);
+  }
+}
+
+void vmaReset(SVMemAllocator *pVMA) {
+  while (TD_SLIST_NELES(&(pVMA->nlist)) > 1) {
+    SVArenaNode *pNode = TD_SLIST_HEAD(&(pVMA->nlist));
+    tSListPop(&(pVMA->nlist));
+    vArenaNodeFree(pNode);
+  }
+
+  SVArenaNode *pNode = TD_SLIST_HEAD(&(pVMA->nlist));
+  pNode->ptr = pNode->data;
+}
+
+void *vmaMalloc(SVMemAllocator *pVMA, uint64_t size) {
+  SVArenaNode *pNode = TD_SLIST_HEAD(&(pVMA->nlist));
+  void *       ptr;
+
+  if (pNode->size < POINTER_DISTANCE(pNode->ptr, pNode->data) + size) {
+    uint64_t capacity = MAX(pVMA->ssize, size);
+    pNode = vArenaNodeNew(capacity);
+    if (pNode == NULL) {
+      // TODO: handle error
+      return NULL;
+    }
+
+    tSListPush(&(pVMA->nlist), pNode);
+  }
+
+  ptr = pNode->ptr;
+  pNode->ptr = POINTER_SHIFT(ptr, size);
+
+  return ptr;
+}
+
+void vmaFree(SVMemAllocator *pVMA, void *ptr) {
+  // TODO
+}
+
+bool vmaIsFull(SVMemAllocator *pVMA) {
+  SVArenaNode *pNode = TD_SLIST_HEAD(&(pVMA->nlist));
+
+  return (TD_SLIST_NELES(&(pVMA->nlist)) > 1) ||
+         (pNode->size < POINTER_DISTANCE(pNode->ptr, pNode->data) + pVMA->lsize);
+}
+
+/* ------------------------ STATIC METHODS ------------------------ */
+static SVArenaNode *vArenaNodeNew(uint64_t capacity) {
+  SVArenaNode *pNode = NULL;
+
+  pNode = (SVArenaNode *)malloc(sizeof(*pNode) + capacity);
+  if (pNode == NULL) {
+    return NULL;
+  }
+
+  pNode->size = capacity;
+  pNode->ptr = pNode->data;
+
+  return pNode;
+}
+
+static void vArenaNodeFree(SVArenaNode *pNode) {
+  if (pNode) {
+    free(pNode);
+  }
+}
\ No newline at end of file
diff --git a/source/dnode/vnode/impl/src/vnodeBufferPool.c b/source/dnode/vnode/impl/src/vnodeBufferPool.c
index 00203ed9b6..1db15c3990 100644
--- a/source/dnode/vnode/impl/src/vnodeBufferPool.c
+++ b/source/dnode/vnode/impl/src/vnodeBufferPool.c
@@ -19,14 +19,90 @@
 #define VNODE_BUF_POOL_SHARDS 3
 
 struct SVBufPool {
-  // buffer pool impl
-  SList      free;
-  SList      incycle;
-  SListNode *inuse;
+  TD_DLIST(SVMemAllocator) free;
+  TD_DLIST(SVMemAllocator) incycle;
+  SVMemAllocator *inuse;
   // MAF for submodules
-  SMemAllocatorFactory maf;
+  // SMemAllocatorFactory maf;
 };
 
+int vnodeOpenBufPool(SVnode *pVnode) {
+  uint64_t capacity;
+  // EVMemAllocatorT type = E_V_ARENA_ALLOCATOR;
+
+  if ((pVnode->pBufPool = (SVBufPool *)calloc(1, sizeof(SVBufPool))) == NULL) {
+    /* TODO */
+    return -1;
+  }
+
+  tDListInit(&(pVnode->pBufPool->free));
+  tDListInit(&(pVnode->pBufPool->incycle));
+
+  pVnode->pBufPool->inuse = NULL;
+
+  // TODO
+  capacity = pVnode->config.wsize / VNODE_BUF_POOL_SHARDS;
+
+  for (int i = 0; i < VNODE_BUF_POOL_SHARDS; i++) {
+    SVMemAllocator *pVMA = vmaCreate(capacity, pVnode->config.ssize, pVnode->config.lsize);
+    if (pVMA == NULL) {
+      // TODO: handle error
+      return -1;
+    }
+
+    tDListAppend(&(pVnode->pBufPool->free), pVMA);
+  }
+
+  return 0;
+}
+
+void vnodeCloseBufPool(SVnode *pVnode) {
+  if (pVnode->pBufPool) {
+    vmaDestroy(pVnode->pBufPool->inuse);
+
+    while (true) {
+      SVMemAllocator *pVMA = TD_DLIST_HEAD(&(pVnode->pBufPool->incycle));
+      if (pVMA == NULL) break;
+      tDListPop(&(pVnode->pBufPool->incycle), pVMA);
+      vmaDestroy(pVMA);
+    }
+
+    while (true) {
+      SVMemAllocator *pVMA = TD_DLIST_HEAD(&(pVnode->pBufPool->free));
+      if (pVMA == NULL) break;
+      tDListPop(&(pVnode->pBufPool->free), pVMA);
+      vmaDestroy(pVMA);
+    }
+
+    free(pVnode->pBufPool);
+    pVnode->pBufPool = NULL;
+  }
+}
+
+void *vnodeMalloc(SVnode *pVnode, uint64_t size) {
+  SVBufPool *pBufPool = pVnode->pBufPool;
+
+  if (pBufPool->inuse == NULL) {
+    while (true) {
+      // TODO: add sem_wait and sem_post
+      pBufPool->inuse = TD_DLIST_HEAD(&(pBufPool->free));
+      if (pBufPool->inuse) {
+        tDListPop(&(pBufPool->free), pBufPool->inuse);
+        break;
+      }
+    }
+  }
+
+  return vmaMalloc(pBufPool->inuse, size);
+}
+
+bool vnodeBufPoolIsFull(SVnode *pVnode) {
+  if (pVnode->pBufPool->inuse == NULL) return false;
+  return vmaIsFull(pVnode->pBufPool->inuse);
+}
+
+#if 0
+
 typedef enum {
   // Heap allocator
   E_V_HEAP_ALLOCATOR = 0,
@@ -57,15 +133,6 @@ typedef struct {
   SListNode *pNode;
 } SVMAWrapper;
 
-typedef struct {
-  T_REF_DECLARE()
-  uint64_t        capacity;
-  EVMemAllocatorT type;
-  union {
-    SVHeapAllocator  vha;
-    SVArenaAllocator vaa;
-  };
-} SVMemAllocator;
 
 static SListNode *    vBufPoolNewNode(uint64_t capacity, EVMemAllocatorT type);
 static void           vBufPoolFreeNode(SListNode *pNode);
@@ -73,106 +140,13 @@ static SMemAllocator *vBufPoolCreateMA(SMemAllocatorFactory *pmaf);
 static void           vBufPoolDestroyMA(SMemAllocatorFactory *pmaf, SMemAllocator *pma);
 static void *         vBufPoolMalloc(SVMemAllocator *pvma, uint64_t size);
 
-int vnodeOpenBufPool(SVnode *pVnode) {
-  uint64_t        capacity;
-  EVMemAllocatorT type = E_V_ARENA_ALLOCATOR;
-
-  if ((pVnode->pBufPool = (SVBufPool *)calloc(1, sizeof(SVBufPool))) == NULL) {
-    /* TODO */
-    return -1;
-  }
-
-  tdListInit(&(pVnode->pBufPool->free), 0);
-  tdListInit(&(pVnode->pBufPool->incycle), 0);
-
-  capacity = pVnode->config.wsize / VNODE_BUF_POOL_SHARDS;
-  if (pVnode->config.isHeapAllocator) {
-    type = E_V_HEAP_ALLOCATOR;
-  }
-
-  for (int i = 0; i < VNODE_BUF_POOL_SHARDS; i++) {
-    SListNode *pNode = vBufPoolNewNode(capacity, type);
-    if (pNode == NULL) {
-      vnodeCloseBufPool(pVnode);
-      return -1;
-    }
-
-    tdListAppendNode(&(pVnode->pBufPool->free), pNode);
-  }
-
-  pVnode->pBufPool->maf.impl = pVnode;
-  pVnode->pBufPool->maf.create = vBufPoolCreateMA;
-  pVnode->pBufPool->maf.destroy = vBufPoolDestroyMA;
-
-  return 0;
-}
-
-void vnodeCloseBufPool(SVnode *pVnode) {
-  SListNode *pNode;
-  if (pVnode->pBufPool) {
-    // Clear free list
-    while ((pNode = tdListPopHead(&(pVnode->pBufPool->free))) != NULL) {
-      vBufPoolFreeNode(pNode);
-    }
-
-    // Clear incycle list
-    while ((pNode = tdListPopHead(&(pVnode->pBufPool->incycle))) != NULL) {
-      vBufPoolFreeNode(pNode);
-    }
-
-    // Free inuse node
-    if (pVnode->pBufPool->inuse) {
-      vBufPoolFreeNode(pVnode->pBufPool->inuse);
-    }
-
-    free(pVnode->pBufPool);
-    pVnode->pBufPool = NULL;
-  }
-}
-
-void *vnodeMalloc(SVnode *pVnode, uint64_t size) {
-  void *ptr;
-
-  if (pVnode->pBufPool->inuse == NULL) {
-    SListNode *pNode;
-    while ((pNode = tdListPopHead(&(pVnode->pBufPool->free))) == NULL) {
-      // todo
-      // tsem_wait();
-      ASSERT(0);
-    }
-
-    pVnode->pBufPool->inuse = pNode;
-  }
-
-  SVMemAllocator *pvma = (SVMemAllocator *)(pVnode->pBufPool->inuse->data);
-  return vBufPoolMalloc(pvma, size);
-}
-
 /* ------------------------ STATIC METHODS ------------------------ */
-static void vArenaAllocatorInit(SVArenaAllocator *pvaa, uint64_t capacity, uint64_t ssize, uint64_t lsize) { /* TODO */
-  pvaa->ssize = ssize;
-  pvaa->lsize = lsize;
-  pvaa->inuse = &pvaa->node;
-
-  pvaa->node.prev = NULL;
-  pvaa->node.size = capacity;
-  pvaa->node.ptr = pvaa->node.data;
-}
-
-static void vArenaAllocatorClear(SVArenaAllocator *pvaa) { /* TODO */
-  while (pvaa->inuse != &(pvaa->node)) {
-    SVArenaNode *pANode = pvaa->inuse;
-    pvaa->inuse = pANode->prev;
-    free(pANode);
-  }
-}
-
 static SListNode *vBufPoolNewNode(uint64_t capacity, EVMemAllocatorT type) {
   SListNode *     pNode;
   SVMemAllocator *pvma;
   uint64_t        msize;
-  uint64_t        ssize = 0;  // TODO
-  uint64_t        lsize = 0;  // TODO
+  uint64_t        ssize = 4096;  // TODO
+  uint64_t        lsize = 1024;  // TODO
 
   msize = sizeof(SListNode) + sizeof(SVMemAllocator);
   if (type == E_V_ARENA_ALLOCATOR) {
@@ -317,4 +291,5 @@ static void vBufPoolDestroyMA(SMemAllocatorFactory *pmaf, SMemAllocator *pma) {
     tdListAppendNode(&(pVnode->pBufPool->free), tdListPopNode(&(pVnode->pBufPool->incycle), pNode));
     // tsem_post(); todo: sem_post
   }
-}
\ No newline at end of file
+}
+#endif
\ No newline at end of file
diff --git a/source/dnode/vnode/impl/src/vnodeCfg.c b/source/dnode/vnode/impl/src/vnodeCfg.c
index 01facba888..f5bb7e35d2 100644
--- a/source/dnode/vnode/impl/src/vnodeCfg.c
+++ b/source/dnode/vnode/impl/src/vnodeCfg.c
@@ -15,7 +15,7 @@
 
 #include "vnodeDef.h"
 
-const SVnodeCfg defaultVnodeOptions = {0}; /* TODO */
+const SVnodeCfg defaultVnodeOptions = {.wsize = 16 * 1024 * 1024, .walCfg = {.level = TAOS_WAL_WRITE}}; /* TODO */
 
 void vnodeOptionsInit(SVnodeCfg *pVnodeOptions) { /* TODO */
   vnodeOptionsCopy(pVnodeOptions, &defaultVnodeOptions);
diff --git a/source/dnode/vnode/impl/src/vnodeCommit.c b/source/dnode/vnode/impl/src/vnodeCommit.c
index 18a0c6d91d..cac7999f59 100644
--- a/source/dnode/vnode/impl/src/vnodeCommit.c
+++ b/source/dnode/vnode/impl/src/vnodeCommit.c
@@ -18,8 +18,6 @@
 static int vnodeStartCommit(SVnode *pVnode);
 static int vnodeEndCommit(SVnode *pVnode);
 
-bool vnodeShouldCommit(SVnode *pVnode) { return false; }
-
 int vnodeAsyncCommit(SVnode *pVnode) {
 #if 0
   if (vnodeStartCommit(pVnode) < 0) {
diff --git a/source/dnode/vnode/impl/src/vnodeMain.c b/source/dnode/vnode/impl/src/vnodeMain.c
index ab33b58858..9b94b4a361 100644
--- a/source/dnode/vnode/impl/src/vnodeMain.c
+++ b/source/dnode/vnode/impl/src/vnodeMain.c
@@ -13,6 +13,7 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "tmacro.h"
 #include "vnodeDef.h"
 
 static SVnode *vnodeNew(const char *path, const SVnodeCfg *pVnodeCfg);
@@ -20,8 +21,14 @@ static void    vnodeFree(SVnode *pVnode);
 static int     vnodeOpenImpl(SVnode *pVnode);
 static void    vnodeCloseImpl(SVnode *pVnode);
 
+TD_DEF_MOD_INIT_FLAG(vnode);
+TD_DEF_MOD_CLEAR_FLAG(vnode);
+
 int vnodeInit() {
-  // TODO
+  if (TD_CHECK_AND_SET_MODE_INIT(vnode) == TD_MOD_INITIALIZED) {
+    return 0;
+  }
+
   if (walInit() < 0) {
     return -1;
   }
@@ -30,6 +37,10 @@ int vnodeInit() {
 }
 
 void vnodeClear() {
+  if (TD_CHECK_AND_SET_MOD_CLEAR(vnode) == TD_MOD_CLEARD) {
+    return;
+  }
+
   walCleanUp();
 }
 
diff --git a/source/dnode/vnode/impl/src/vnodeMemAllocator.c b/source/dnode/vnode/impl/src/vnodeMemAllocator.c
deleted file mode 100644
index 902014eb47..0000000000
--- a/source/dnode/vnode/impl/src/vnodeMemAllocator.c
+++ /dev/null
@@ -1,113 +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/>.
- */
-
-#include "vnodeDef.h"
-
-SMemAllocator *vnodeCreateMemAllocator(SVnode *pVnode) {
-  SMemAllocator *pma = NULL;
-  /* TODO */
-  return pma;
-}
-
-void vnodeDestroyMemAllocator(SMemAllocator *pma) {
-  // TODO
-}
-
-#if 0
-#define VNODE_HEAP_ALLOCATOR 0
-#define VNODE_ARENA_ALLOCATOR 1
-
-typedef struct {
-  uint64_t tsize;
-  uint64_t used;
-} SVHeapAllocator;
-
-typedef struct SVArenaNode {
-  struct SVArenaNode *prev;
-  void *              nptr;
-  char                data[];
-} SVArenaNode;
-
-typedef struct {
-  SVArenaNode *inuse;
-  SVArenaNode  node;
-} SVArenaAllocator;
-
-typedef struct {
-  int8_t   type;
-  uint64_t tsize;
-  T_REF_DECLARE()
-  union {
-    SVHeapAllocator  vha;
-    SVArenaAllocator vaa;
-  };
-} SVMemAllocator;
-
-SMemAllocator *vnodeCreateMemAllocator(int8_t type, uint64_t tsize, uint64_t ssize /* step size only for arena */) {
-  SMemAllocator * pma;
-  uint64_t        msize;
-  SVMemAllocator *pva;
-
-  msize = sizeof(*pma) + sizeof(SVMemAllocator);
-  if (type == VNODE_ARENA_ALLOCATOR) {
-    msize += tsize;
-  }
-
-  pma = (SMemAllocator *)calloc(1, msize);
-  if (pma == NULL) {
-    return NULL;
-  }
-
-  pma->impl = POINTER_SHIFT(pma, sizeof(*pma));
-  pva = (SVMemAllocator *)(pma->impl);
-  pva->type = type;
-  pva->tsize = tsize;
-
-  if (type == VNODE_HEAP_ALLOCATOR) {
-    pma->malloc = NULL;
-    pma->calloc = NULL;
-    pma->realloc = NULL;
-    pma->free = NULL;
-    pma->usage = NULL;
-  } else if (type == VNODE_ARENA_ALLOCATOR) {
-    pma->malloc = NULL;
-    pma->calloc = NULL;
-    pma->realloc = NULL;
-    pma->free = NULL;
-    pma->usage = NULL;
-  } else {
-    ASSERT(0);
-  }
-
-  return pma;
-}
-
-void vnodeDestroyMemAllocator(SMemAllocator *pma) {
-  // TODO
-}
-
-void vnodeRefMemAllocator(SMemAllocator *pma) {
-  // TODO
-}
-
-void vnodeUnrefMemAllocator(SMemAllocator *pma) {
-  // TODO
-}
-
-/* ------------------------ Heap Allocator IMPL ------------------------ */
-
-/* ------------------------ Arena Allocator IMPL ------------------------ */
-
-#endif
\ No newline at end of file
diff --git a/source/dnode/vnode/impl/test/CMakeLists.txt b/source/dnode/vnode/impl/test/CMakeLists.txt
index 83506a4fde..e1226331e9 100644
--- a/source/dnode/vnode/impl/test/CMakeLists.txt
+++ b/source/dnode/vnode/impl/test/CMakeLists.txt
@@ -4,4 +4,9 @@ target_sources(vnodeApiTests
     PRIVATE
     "vnodeApiTests.cpp"
 )
-target_link_libraries(vnodeApiTests vnode gtest gtest_main)
\ No newline at end of file
+target_link_libraries(vnodeApiTests vnode gtest gtest_main)
+
+add_test(
+    NAME vnode_api_tests 
+    COMMAND ${CMAKE_CURRENT_BINARY_DIR}/vnodeApiTests
+    )
\ No newline at end of file
diff --git a/source/dnode/vnode/impl/test/vnodeApiTests.cpp b/source/dnode/vnode/impl/test/vnodeApiTests.cpp
index df784181b7..ac2ccbc132 100644
--- a/source/dnode/vnode/impl/test/vnodeApiTests.cpp
+++ b/source/dnode/vnode/impl/test/vnodeApiTests.cpp
@@ -1,3 +1,14 @@
+/**
+ * @file vnodeApiTests.cpp
+ * @author hzcheng (hzcheng@taosdata.com)
+ * @brief VNODE module API tests
+ * @version 0.1
+ * @date 2021-12-13
+ *
+ * @copyright Copyright (c) 2021
+ *
+ */
+
 #include <gtest/gtest.h>
 #include <iostream>
 
diff --git a/source/libs/wal/inc/walInt.h b/source/libs/wal/inc/walInt.h
index f8f2e2eadd..ec01f7d7fc 100644
--- a/source/libs/wal/inc/walInt.h
+++ b/source/libs/wal/inc/walInt.h
@@ -90,7 +90,7 @@ static inline int walValidHeadCksum(SWalHead* pHead) {
 }
 
 static inline int walValidBodyCksum(SWalHead* pHead) {
-  return taosCheckChecksum((uint8_t*)pHead->head.cont, pHead->head.len, pHead->cksumBody);
+  return taosCheckChecksum((uint8_t*)pHead->head.body, pHead->head.len, pHead->cksumBody);
 }
 
 static inline int walValidCksum(SWalHead *pHead, void* body, int64_t bodyLen) {
diff --git a/source/libs/wal/src/walMeta.c b/source/libs/wal/src/walMeta.c
index 705cf051be..49f4fde3a0 100644
--- a/source/libs/wal/src/walMeta.c
+++ b/source/libs/wal/src/walMeta.c
@@ -25,15 +25,15 @@
 #include <regex.h>
 
 int64_t walGetFirstVer(SWal *pWal) {
-  return pWal->firstVersion;
+  return pWal->vers.firstVer;
 }
 
 int64_t walGetSnaphostVer(SWal *pWal) {
-  return pWal->snapshotVersion;
+  return pWal->vers.snapshotVer;
 }
 
 int64_t walGetLastVer(SWal *pWal) {
-  return pWal->lastVersion;
+  return pWal->vers.lastVer;
 }
 
 int walRollFileInfo(SWal* pWal) {
@@ -42,7 +42,7 @@ int walRollFileInfo(SWal* pWal) {
   SArray* pArray = pWal->fileInfoSet;
   if(taosArrayGetSize(pArray) != 0) {
     WalFileInfo *pInfo = taosArrayGetLast(pArray);
-    pInfo->lastVer = pWal->lastVersion;
+    pInfo->lastVer = pWal->vers.lastVer;
     pInfo->closeTs = ts;
   }
 
@@ -51,7 +51,7 @@ int walRollFileInfo(SWal* pWal) {
   if(pNewInfo == NULL) {
     return -1;
   }
-  pNewInfo->firstVer = pWal->lastVersion + 1;
+  pNewInfo->firstVer = pWal->vers.lastVer + 1;
   pNewInfo->lastVer = -1;
   pNewInfo->createTs = ts;
   pNewInfo->closeTs = -1;
@@ -74,13 +74,13 @@ char* walMetaSerialize(SWal* pWal) {
     return NULL;
   }
   cJSON_AddItemToObject(pRoot, "meta", pMeta);
-  sprintf(buf, "%" PRId64, pWal->firstVersion);
+  sprintf(buf, "%" PRId64, pWal->vers.firstVer);
   cJSON_AddStringToObject(pMeta, "firstVer", buf);
-  sprintf(buf, "%" PRId64, pWal->snapshotVersion);
+  sprintf(buf, "%" PRId64, pWal->vers.snapshotVer);
   cJSON_AddStringToObject(pMeta, "snapshotVer", buf);
-  sprintf(buf, "%" PRId64, pWal->commitVersion);
+  sprintf(buf, "%" PRId64, pWal->vers.commitVer);
   cJSON_AddStringToObject(pMeta, "commitVer", buf);
-  sprintf(buf, "%" PRId64, pWal->lastVersion);
+  sprintf(buf, "%" PRId64, pWal->vers.lastVer);
   cJSON_AddStringToObject(pMeta, "lastVer", buf);
 
   cJSON_AddItemToObject(pRoot, "files", pFiles);
@@ -116,13 +116,13 @@ int walMetaDeserialize(SWal* pWal, const char* bytes) {
   pRoot = cJSON_Parse(bytes);
   pMeta = cJSON_GetObjectItem(pRoot, "meta");
   pField = cJSON_GetObjectItem(pMeta, "firstVer");
-  pWal->firstVersion = atoll(cJSON_GetStringValue(pField));
+  pWal->vers.firstVer = atoll(cJSON_GetStringValue(pField));
   pField = cJSON_GetObjectItem(pMeta, "snapshotVer");
-  pWal->snapshotVersion = atoll(cJSON_GetStringValue(pField));
+  pWal->vers.snapshotVer = atoll(cJSON_GetStringValue(pField));
   pField = cJSON_GetObjectItem(pMeta, "commitVer");
-  pWal->commitVersion = atoll(cJSON_GetStringValue(pField));
+  pWal->vers.commitVer = atoll(cJSON_GetStringValue(pField));
   pField = cJSON_GetObjectItem(pMeta, "lastVer");
-  pWal->lastVersion = atoll(cJSON_GetStringValue(pField));
+  pWal->vers.lastVer = atoll(cJSON_GetStringValue(pField));
 
   pFiles = cJSON_GetObjectItem(pRoot, "files");
   int sz = cJSON_GetArraySize(pFiles);
@@ -161,7 +161,7 @@ static int walFindCurMetaVer(SWal* pWal) {
 
   DIR *dir = opendir(pWal->path); 
   if(dir == NULL) {
-    wError("vgId:%d, path:%s, failed to open since %s", pWal->vgId, pWal->path, strerror(errno));
+    wError("vgId:%d, path:%s, failed to open since %s", pWal->cfg.vgId, pWal->path, strerror(errno));
     return -1;
   }
 
diff --git a/source/libs/wal/src/walMgmt.c b/source/libs/wal/src/walMgmt.c
index 3e47d18df6..7c100b4883 100644
--- a/source/libs/wal/src/walMgmt.c
+++ b/source/libs/wal/src/walMgmt.c
@@ -68,9 +68,12 @@ int32_t walInit() {
 }
 
 void walCleanUp() {
+  int old = atomic_val_compare_exchange_8(&tsWal.inited, 1, 0);
+  if(old == 0) {
+    return;
+  }
   walStopThread();
   taosCloseRef(tsWal.refSetId);
-  atomic_store_8(&tsWal.inited, 0);
   wInfo("wal module is cleaned up");
 }
 
@@ -86,21 +89,15 @@ SWal *walOpen(const char *path, SWalCfg *pCfg) {
   pWal->writeCur = -1;
 
   //set config
-  pWal->vgId = pCfg->vgId;
-  pWal->fsyncPeriod = pCfg->fsyncPeriod;
-  pWal->rollPeriod = pCfg->rollPeriod;
-  pWal->segSize = pCfg->segSize;
-  pWal->retentionSize = pCfg->retentionSize;
-  pWal->retentionPeriod = pCfg->retentionPeriod;
-  pWal->level = pCfg->walLevel;
+  memcpy(&pWal->cfg, pCfg, sizeof(SWalCfg));
 
   //init version info
-  pWal->firstVersion = -1;
-  pWal->commitVersion = -1;
-  pWal->snapshotVersion = -1;
-  pWal->lastVersion = -1;
+  pWal->vers.firstVer = -1;
+  pWal->vers.commitVer = -1;
+  pWal->vers.snapshotVer = -1;
+  pWal->vers.lastVer = -1;
 
-  pWal->snapshottingVer = -1;
+  pWal->vers.verInSnapshotting = -1;
 
   pWal->totSize = 0;
 
@@ -108,8 +105,8 @@ SWal *walOpen(const char *path, SWalCfg *pCfg) {
   pWal->lastRollSeq = -1;
 
   //init write buffer
-  memset(&pWal->head, 0, sizeof(SWalHead));
-  pWal->head.head.sver = 0;
+  memset(&pWal->writeHead, 0, sizeof(SWalHead));
+  pWal->writeHead.head.sver = 0;
 
   tstrncpy(pWal->path, path, sizeof(pWal->path));
   pthread_mutex_init(&pWal->mutex, NULL);
@@ -129,7 +126,7 @@ SWal *walOpen(const char *path, SWalCfg *pCfg) {
   }
   walReadMeta(pWal);
 
-  wDebug("vgId:%d, wal:%p is opened, level:%d fsyncPeriod:%d", pWal->vgId, pWal, pWal->level, pWal->fsyncPeriod);
+  wDebug("vgId:%d, wal:%p is opened, level:%d fsyncPeriod:%d", pWal->cfg.vgId, pWal, pWal->cfg.level, pWal->cfg.fsyncPeriod);
 
   return pWal;
 }
@@ -137,17 +134,17 @@ SWal *walOpen(const char *path, SWalCfg *pCfg) {
 int32_t walAlter(SWal *pWal, SWalCfg *pCfg) {
   if (pWal == NULL) return TSDB_CODE_WAL_APP_ERROR;
 
-  if (pWal->level == pCfg->walLevel && pWal->fsyncPeriod == pCfg->fsyncPeriod) {
-    wDebug("vgId:%d, old walLevel:%d fsync:%d, new walLevel:%d fsync:%d not change", pWal->vgId, pWal->level,
-           pWal->fsyncPeriod, pCfg->walLevel, pCfg->fsyncPeriod);
+  if (pWal->cfg.level == pCfg->level && pWal->cfg.fsyncPeriod == pCfg->fsyncPeriod) {
+    wDebug("vgId:%d, old walLevel:%d fsync:%d, new walLevel:%d fsync:%d not change", pWal->cfg.vgId, pWal->cfg.level,
+           pWal->cfg.fsyncPeriod, pCfg->level, pCfg->fsyncPeriod);
     return 0;
   }
 
-  wInfo("vgId:%d, change old walLevel:%d fsync:%d, new walLevel:%d fsync:%d", pWal->vgId, pWal->level,
-        pWal->fsyncPeriod, pCfg->walLevel, pCfg->fsyncPeriod);
+  wInfo("vgId:%d, change old walLevel:%d fsync:%d, new walLevel:%d fsync:%d", pWal->cfg.vgId, pWal->cfg.level,
+        pWal->cfg.fsyncPeriod, pCfg->level, pCfg->fsyncPeriod);
 
-  pWal->level = pCfg->walLevel;
-  pWal->fsyncPeriod = pCfg->fsyncPeriod;
+  pWal->cfg.level = pCfg->level;
+  pWal->cfg.fsyncPeriod = pCfg->fsyncPeriod;
   pWal->fsyncSeq = pCfg->fsyncPeriod / 1000;
   if (pWal->fsyncSeq <= 0) pWal->fsyncSeq = 1;
 
@@ -171,22 +168,22 @@ void walClose(SWal *pWal) {
 
 static int32_t walInitObj(SWal *pWal) {
   if (taosMkDir(pWal->path) != 0) {
-    wError("vgId:%d, path:%s, failed to create directory since %s", pWal->vgId, pWal->path, strerror(errno));
+    wError("vgId:%d, path:%s, failed to create directory since %s", pWal->cfg.vgId, pWal->path, strerror(errno));
     return TAOS_SYSTEM_ERROR(errno);
   }
   pWal->fileInfoSet = taosArrayInit(8, sizeof(WalFileInfo));
   if(pWal->fileInfoSet == NULL) {
-    wError("vgId:%d, path:%s, failed to init taosArray %s", pWal->vgId, pWal->path, strerror(errno));
+    wError("vgId:%d, path:%s, failed to init taosArray %s", pWal->cfg.vgId, pWal->path, strerror(errno));
     return TAOS_SYSTEM_ERROR(errno);
   }
 
-  wDebug("vgId:%d, object is initialized", pWal->vgId);
+  wDebug("vgId:%d, object is initialized", pWal->cfg.vgId);
   return 0;
 }
 
 static void walFreeObj(void *wal) {
   SWal *pWal = wal;
-  wDebug("vgId:%d, wal:%p is freed", pWal->vgId, pWal);
+  wDebug("vgId:%d, wal:%p is freed", pWal->cfg.vgId, pWal);
 
   tfClose(pWal->writeLogTfd);
   tfClose(pWal->writeIdxTfd);
@@ -197,7 +194,7 @@ static void walFreeObj(void *wal) {
 }
 
 static bool walNeedFsync(SWal *pWal) {
-  if (pWal->fsyncPeriod <= 0 || pWal->level != TAOS_WAL_FSYNC) {
+  if (pWal->cfg.fsyncPeriod <= 0 || pWal->cfg.level != TAOS_WAL_FSYNC) {
     return false;
   }
 
@@ -217,10 +214,10 @@ static void walFsyncAll() {
   SWal *pWal = taosIterateRef(tsWal.refSetId, 0);
   while (pWal) {
     if (walNeedFsync(pWal)) {
-      wTrace("vgId:%d, do fsync, level:%d seq:%d rseq:%d", pWal->vgId, pWal->level, pWal->fsyncSeq, atomic_load_32(&tsWal.seq));
+      wTrace("vgId:%d, do fsync, level:%d seq:%d rseq:%d", pWal->cfg.vgId, pWal->cfg.level, pWal->fsyncSeq, atomic_load_32(&tsWal.seq));
       int32_t code = tfFsync(pWal->writeLogTfd);
       if (code != 0) {
-        wError("vgId:%d, file:%"PRId64".log, failed to fsync since %s", pWal->vgId, walGetLastFileFirstVer(pWal), strerror(code));
+        wError("vgId:%d, file:%"PRId64".log, failed to fsync since %s", pWal->cfg.vgId, walGetLastFileFirstVer(pWal), strerror(code));
       }
     }
     pWal = taosIterateRef(tsWal.refSetId, pWal->refId);
diff --git a/source/libs/wal/src/walRead.c b/source/libs/wal/src/walRead.c
index 27dffddf83..554a5c846b 100644
--- a/source/libs/wal/src/walRead.c
+++ b/source/libs/wal/src/walRead.c
@@ -16,6 +16,147 @@
 #include "walInt.h"
 #include "tfile.h"
 
+SWalReadHandle* walOpenReadHandle(SWal* pWal) {
+  SWalReadHandle *pRead = malloc(sizeof(SWalReadHandle));
+  if(pRead == NULL) {
+    return NULL;
+  }
+  memset(pRead, 0, sizeof(SWalReadHandle));
+  pRead->pWal = pWal;
+  pRead->readIdxTfd = -1;
+  pRead->readLogTfd = -1;
+  return NULL;
+}
+
+void walCloseReadHandle(SWalReadHandle *pRead) {
+  tfClose(pRead->readIdxTfd);
+  tfClose(pRead->readLogTfd);
+  free(pRead);
+}
+
+int32_t walRegisterRead(SWalReadHandle *pRead, int64_t ver) {
+  return 0;
+}
+
+static int32_t walReadSeekFilePos(SWalReadHandle *pRead, int64_t fileFirstVer, int64_t ver) {
+  int code = 0;
+
+  int64_t idxTfd = pRead->readIdxTfd;
+  int64_t logTfd = pRead->readLogTfd;
+  
+  //seek position
+  int64_t offset = (ver - fileFirstVer) * WAL_IDX_ENTRY_SIZE;
+  code = tfLseek(idxTfd, offset, SEEK_SET);
+  if(code != 0) {
+    return -1;
+  }
+  WalIdxEntry entry;
+  code = tfRead(idxTfd, &entry, sizeof(WalIdxEntry));
+  if(code != 0) {
+    return -1;
+  }
+  //TODO:deserialize
+  ASSERT(entry.ver == ver);
+  code = tfLseek(logTfd, entry.offset, SEEK_SET);
+  if (code != 0) {
+    return -1;
+  }
+  return code;
+}
+
+static int32_t walReadChangeFile(SWalReadHandle *pRead, int64_t fileFirstVer) {
+  char fnameStr[WAL_FILE_LEN];
+
+  tfClose(pRead->readIdxTfd);
+  tfClose(pRead->readLogTfd);
+
+  walBuildLogName(pRead->pWal, fileFirstVer, fnameStr);
+  int logTfd = tfOpenRead(fnameStr);
+  if(logTfd < 0) {
+    return -1;
+  }
+
+  walBuildIdxName(pRead->pWal, fileFirstVer, fnameStr);
+  int idxTfd = tfOpenRead(fnameStr);
+  if(idxTfd < 0) {
+    return -1;
+  }
+
+  pRead->readLogTfd = logTfd;
+  pRead->readIdxTfd = idxTfd;
+  return 0;
+}
+
+static int32_t walReadSeekVer(SWalReadHandle *pRead, int64_t ver) {
+  int code;
+  SWal *pWal = pRead->pWal;
+  if(ver == pWal->vers.lastVer) {
+    return 0;
+  }
+  if(ver > pWal->vers.lastVer || ver < pWal->vers.firstVer) {
+    return -1;
+  }
+  if(ver < pWal->vers.snapshotVer) {
+
+  }
+
+  WalFileInfo tmpInfo;
+  tmpInfo.firstVer = ver;
+  //bsearch in fileSet
+  WalFileInfo* pRet = taosArraySearch(pWal->fileInfoSet, &tmpInfo, compareWalFileInfo, TD_LE);
+  ASSERT(pRet != NULL);
+  if(pRead->curFileFirstVer != pRet->firstVer) {
+    code = walReadChangeFile(pRead, pRet->firstVer);
+    if(code < 0) {
+      //TODO: set error flag
+      return -1;
+    }
+  }
+
+  code = walReadSeekFilePos(pRead, pRet->firstVer, ver);
+  if(code < 0) {
+    return -1;
+  }
+  pRead->curVersion = ver;
+   
+  return 0;
+}
+
+int32_t walReadWithHandle(SWalReadHandle *pRead, int64_t ver) {
+  int code;
+  //TODO: check wal life
+  if(pRead->curVersion != ver) {
+    walReadSeekVer(pRead, ver);   
+  }
+
+  if(!tfValid(pRead->readLogTfd)) return -1;
+
+  if(sizeof(SWalHead) != tfRead(pRead->readLogTfd, &pRead->head, sizeof(SWalHead))) {
+    return -1;
+  }
+  code = walValidHeadCksum(&pRead->head);
+  if(code != 0) {
+    return -1;
+  }
+  if(pRead->capacity < pRead->head.head.len) {
+    void* ptr = realloc(pRead, pRead->head.head.len);
+    if(ptr == NULL) {
+      return -1;
+    }
+    pRead = ptr;
+    pRead->capacity = pRead->head.head.len;
+  }
+  if(pRead->head.head.len != tfRead(pRead->readLogTfd, &pRead->head.head.body, pRead->head.head.len)) {
+    return -1;
+  }
+  code = walValidBodyCksum(&pRead->head);
+  if(code != 0) {
+    return -1;
+  }
+
+  return 0;
+}
+
 int32_t walRead(SWal *pWal, SWalHead **ppHead, int64_t ver) {
   int code;
   code = walSeekVer(pWal, ver);
@@ -42,7 +183,7 @@ int32_t walRead(SWal *pWal, SWalHead **ppHead, int64_t ver) {
     *ppHead = NULL;
     return -1;
   }
-  if(tfRead(pWal->writeLogTfd, (*ppHead)->head.cont, (*ppHead)->head.len) != (*ppHead)->head.len) {
+  if(tfRead(pWal->writeLogTfd, (*ppHead)->head.body, (*ppHead)->head.len) != (*ppHead)->head.len) {
     return -1;
   }
   //TODO: endian compatibility processing after read
diff --git a/source/libs/wal/src/walSeek.c b/source/libs/wal/src/walSeek.c
index 48272f8f32..953aae703c 100644
--- a/source/libs/wal/src/walSeek.c
+++ b/source/libs/wal/src/walSeek.c
@@ -78,10 +78,12 @@ int walChangeFile(SWal *pWal, int64_t ver) {
   code = tfClose(pWal->writeLogTfd);
   if(code != 0) {
    //TODO 
+    return -1;
   }
   code = tfClose(pWal->writeIdxTfd);
   if(code != 0) {
    //TODO 
+    return -1;
   }
   WalFileInfo tmpInfo;
   tmpInfo.firstVer = ver;
@@ -106,24 +108,19 @@ int walChangeFile(SWal *pWal, int64_t ver) {
 
   pWal->writeLogTfd = logTfd;
   pWal->writeIdxTfd = idxTfd;
-  return code;
-}
-
-int walGetVerOffset(SWal* pWal, int64_t ver) {
-  int code;
-  return 0;
+  return fileFirstVer;
 }
 
 int walSeekVer(SWal *pWal, int64_t ver) {
   int code;
-  if(ver == pWal->lastVersion) {
+  if(ver == pWal->vers.lastVer) {
     return 0;
   }
-  if(ver > pWal->lastVersion || ver < pWal->firstVersion) {
+  if(ver > pWal->vers.lastVer|| ver < pWal->vers.firstVer) {
     return -1;
   }
-  if(ver < pWal->snapshotVersion) {
-    //TODO: set flag to prevent roll back
+  if(ver < pWal->vers.snapshotVer) {
+
   }
   if(ver < walGetCurFileFirstVer(pWal) || (ver > walGetCurFileLastVer(pWal))) {
     code = walChangeFile(pWal, ver);
diff --git a/source/libs/wal/src/walUtil.c b/source/libs/wal/src/walUtil.c
index c88cc918fe..849d0c3e51 100644
--- a/source/libs/wal/src/walUtil.c
+++ b/source/libs/wal/src/walUtil.c
@@ -17,6 +17,7 @@
 #include "os.h"
 #include "walInt.h"
 
+#if 0
 int32_t walGetNextFile(SWal *pWal, int64_t *nextFileId) {
   int64_t curFileId = *nextFileId;
   int64_t minFileId = INT64_MAX;
@@ -116,3 +117,4 @@ int32_t walGetNewFile(SWal *pWal, int64_t *newFileId) {
 
   return 0;
 }
+#endif
diff --git a/source/libs/wal/src/walWrite.c b/source/libs/wal/src/walWrite.c
index 972ac5c682..44e8cec153 100644
--- a/source/libs/wal/src/walWrite.c
+++ b/source/libs/wal/src/walWrite.c
@@ -114,22 +114,22 @@ void walRemoveAllOldFiles(void *handle) {
 #endif
 
 int32_t walCommit(SWal *pWal, int64_t ver) {
-  ASSERT(pWal->commitVersion >= pWal->snapshotVersion);
-  ASSERT(pWal->commitVersion <= pWal->lastVersion);
-  if(ver < pWal->commitVersion || ver > pWal->lastVersion) {
+  ASSERT(pWal->vers.commitVer >= pWal->vers.snapshotVer);
+  ASSERT(pWal->vers.commitVer <= pWal->vers.lastVer);
+  if(ver < pWal->vers.commitVer || ver > pWal->vers.lastVer) {
     return -1;
   }
-  pWal->commitVersion = ver;
+  pWal->vers.commitVer = ver;
   return 0;
 }
 
 int32_t walRollback(SWal *pWal, int64_t ver) {
   int code;
   char fnameStr[WAL_FILE_LEN];
-  if(ver == pWal->lastVersion) {
+  if(ver == pWal->vers.lastVer) {
     return 0;
   }
-  if(ver > pWal->lastVersion || ver < pWal->commitVersion) {
+  if(ver > pWal->vers.lastVer || ver < pWal->vers.commitVer) {
     return -1;
   }
   pthread_mutex_lock(&pWal->mutex);
@@ -220,7 +220,7 @@ int32_t walRollback(SWal *pWal, int64_t ver) {
   if(code < 0) {
     return -1;
   }
-  pWal->lastVersion = ver - 1;
+  pWal->vers.lastVer = ver - 1;
   ((WalFileInfo*)taosArrayGetLast(pWal->fileInfoSet))->lastVer = ver - 1;
   ((WalFileInfo*)taosArrayGetLast(pWal->fileInfoSet))->fileSize = entry.offset;
 
@@ -230,9 +230,9 @@ int32_t walRollback(SWal *pWal, int64_t ver) {
 }
 
 int32_t walBeginTakeSnapshot(SWal* pWal, int64_t ver) {
-  pWal->snapshottingVer = ver;
+  pWal->vers.verInSnapshotting = ver;
   //check file rolling
-  if(pWal->retentionPeriod == 0) {
+  if(pWal->cfg.retentionPeriod == 0) {
     walRoll(pWal);
   }
 
@@ -240,10 +240,10 @@ int32_t walBeginTakeSnapshot(SWal* pWal, int64_t ver) {
 }
 
 int32_t walEndTakeSnapshot(SWal *pWal) {
-  int64_t ver = pWal->snapshottingVer;
+  int64_t ver = pWal->vers.verInSnapshotting;
   if(ver == -1) return -1;
 
-  pWal->snapshotVersion = ver;
+  pWal->vers.snapshotVer = ver;
   int ts = taosGetTimestampSec();
 
   int deleteCnt = 0;
@@ -257,8 +257,8 @@ int32_t walEndTakeSnapshot(SWal *pWal) {
   }
   //iterate files, until the searched result
   for(WalFileInfo* iter = pWal->fileInfoSet->pData; iter < pInfo; iter++) {
-    if(pWal->totSize > pWal->retentionSize ||
-        iter->closeTs + pWal->retentionPeriod > ts) {
+    if(pWal->totSize > pWal->cfg.retentionSize ||
+        iter->closeTs + pWal->cfg.retentionPeriod > ts) {
       //delete according to file size or close time
       deleteCnt++;
       newTotSize -= iter->fileSize;
@@ -278,13 +278,13 @@ int32_t walEndTakeSnapshot(SWal *pWal) {
   taosArrayPopFrontBatch(pWal->fileInfoSet, deleteCnt); 
   if(taosArrayGetSize(pWal->fileInfoSet) == 0) {
     pWal->writeCur = -1;
-    pWal->firstVersion = -1;
+    pWal->vers.firstVer = -1;
   } else {
-    pWal->firstVersion = ((WalFileInfo*)taosArrayGet(pWal->fileInfoSet, 0))->firstVer;
+    pWal->vers.firstVer = ((WalFileInfo*)taosArrayGet(pWal->fileInfoSet, 0))->firstVer;
   }
   pWal->writeCur = taosArrayGetSize(pWal->fileInfoSet) - 1;;
   pWal->totSize = newTotSize;
-  pWal->snapshottingVer = -1;
+  pWal->vers.verInSnapshotting = -1;
 
   //save snapshot ver, commit ver
   int code = walWriteMeta(pWal);
@@ -311,7 +311,7 @@ int walRoll(SWal *pWal) {
   }
   int64_t idxTfd, logTfd;
   //create new file
-  int64_t newFileFirstVersion = pWal->lastVersion + 1;
+  int64_t newFileFirstVersion = pWal->vers.lastVer + 1;
   char fnameStr[WAL_FILE_LEN];
   walBuildIdxName(pWal, newFileFirstVersion, fnameStr);
   idxTfd = tfOpenCreateWrite(fnameStr);
@@ -357,18 +357,18 @@ int64_t walWrite(SWal *pWal, int64_t index, uint8_t msgType, const void *body, i
   int code = 0;
 
   // no wal
-  if (pWal->level == TAOS_WAL_NOLOG) return 0;
+  if (pWal->cfg.level == TAOS_WAL_NOLOG) return 0;
 
-  if (index == pWal->lastVersion + 1) {
+  if (index == pWal->vers.lastVer + 1) {
     if(taosArrayGetSize(pWal->fileInfoSet) == 0) {
-      pWal->firstVersion = index;
+      pWal->vers.firstVer = index;
       code = walRoll(pWal);
       ASSERT(code == 0);
     } else {
       int64_t passed = walGetSeq() - pWal->lastRollSeq;
-      if(pWal->rollPeriod != -1 && pWal->rollPeriod != 0 && passed > pWal->rollPeriod) {
+      if(pWal->cfg.rollPeriod != -1 && pWal->cfg.rollPeriod != 0 && passed > pWal->cfg.rollPeriod) {
         walRoll(pWal);
-      } else if(pWal->segSize != -1 && pWal->segSize != 0 && walGetLastFileSize(pWal) > pWal->segSize) {
+      } else if(pWal->cfg.segSize != -1 && pWal->cfg.segSize != 0 && walGetLastFileSize(pWal) > pWal->cfg.segSize) {
         walRoll(pWal);
       }
     }
@@ -380,23 +380,23 @@ int64_t walWrite(SWal *pWal, int64_t index, uint8_t msgType, const void *body, i
   /*if (!tfValid(pWal->curLogTfd)) return 0;*/
 
   pthread_mutex_lock(&pWal->mutex);
-  pWal->head.head.version = index;
+  pWal->writeHead.head.version = index;
 
-  pWal->head.head.len = bodyLen;
-  pWal->head.head.msgType = msgType;
-  pWal->head.cksumHead = walCalcHeadCksum(&pWal->head);
-  pWal->head.cksumBody = walCalcBodyCksum(body, bodyLen);
+  pWal->writeHead.head.len = bodyLen;
+  pWal->writeHead.head.msgType = msgType;
+  pWal->writeHead.cksumHead = walCalcHeadCksum(&pWal->writeHead);
+  pWal->writeHead.cksumBody = walCalcBodyCksum(body, bodyLen);
 
-  if (tfWrite(pWal->writeLogTfd, &pWal->head, sizeof(SWalHead)) != sizeof(SWalHead)) {
+  if (tfWrite(pWal->writeLogTfd, &pWal->writeHead, sizeof(SWalHead)) != sizeof(SWalHead)) {
     //ftruncate
     code = TAOS_SYSTEM_ERROR(errno);
-    wError("vgId:%d, file:%"PRId64".log, failed to write since %s", pWal->vgId, walGetLastFileFirstVer(pWal), strerror(errno));
+    wError("vgId:%d, file:%"PRId64".log, failed to write since %s", pWal->cfg.vgId, walGetLastFileFirstVer(pWal), strerror(errno));
   }
 
   if (tfWrite(pWal->writeLogTfd, &body, bodyLen) != bodyLen) {
     //ftruncate
     code = TAOS_SYSTEM_ERROR(errno);
-    wError("vgId:%d, file:%"PRId64".log, failed to write since %s", pWal->vgId, walGetLastFileFirstVer(pWal), strerror(errno));
+    wError("vgId:%d, file:%"PRId64".log, failed to write since %s", pWal->cfg.vgId, walGetLastFileFirstVer(pWal), strerror(errno));
   }
   code = walWriteIndex(pWal, index, walGetCurFileOffset(pWal));
   if(code != 0) {
@@ -405,7 +405,7 @@ int64_t walWrite(SWal *pWal, int64_t index, uint8_t msgType, const void *body, i
   }
 
   //set status
-  pWal->lastVersion = index;
+  pWal->vers.lastVer = index;
   pWal->totSize += sizeof(SWalHead) + bodyLen;
   walGetCurFileInfo(pWal)->lastVer = index;
   walGetCurFileInfo(pWal)->fileSize += sizeof(SWalHead) + bodyLen;
@@ -416,10 +416,10 @@ int64_t walWrite(SWal *pWal, int64_t index, uint8_t msgType, const void *body, i
 }
 
 void walFsync(SWal *pWal, bool forceFsync) {
-  if (forceFsync || (pWal->level == TAOS_WAL_FSYNC && pWal->fsyncPeriod == 0)) {
-    wTrace("vgId:%d, fileId:%"PRId64".log, do fsync", pWal->vgId, walGetCurFileFirstVer(pWal));
+  if (forceFsync || (pWal->cfg.level == TAOS_WAL_FSYNC && pWal->cfg.fsyncPeriod == 0)) {
+    wTrace("vgId:%d, fileId:%"PRId64".log, do fsync", pWal->cfg.vgId, walGetCurFileFirstVer(pWal));
     if (tfFsync(pWal->writeLogTfd) < 0) {
-      wError("vgId:%d, file:%"PRId64".log, fsync failed since %s", pWal->vgId, walGetCurFileFirstVer(pWal), strerror(errno));
+      wError("vgId:%d, file:%"PRId64".log, fsync failed since %s", pWal->cfg.vgId, walGetCurFileFirstVer(pWal), strerror(errno));
     }
   }
 }
@@ -492,29 +492,29 @@ int32_t walGetWalFile(void *handle, char *fileName, int64_t *fileId) {
 }
 #endif
 
-static int walValidateOffset(SWal* pWal, int64_t ver) {
-  int code = 0;
-  SWalHead *pHead = NULL;
-  code = (int)walRead(pWal, &pHead, ver);
-  if(pHead->head.version != ver) {
-    return -1;
-  }
-  return 0;
-}
+/*static int walValidateOffset(SWal* pWal, int64_t ver) {*/
+  /*int code = 0;*/
+  /*SWalHead *pHead = NULL;*/
+  /*code = (int)walRead(pWal, &pHead, ver);*/
+  /*if(pHead->head.version != ver) {*/
+    /*return -1;*/
+  /*}*/
+  /*return 0;*/
+/*}*/
 
-static int64_t walGetOffset(SWal* pWal, int64_t ver) {
-  int code = walSeekVer(pWal, ver);
-  if(code != 0) {
-    return -1;
-  }
+/*static int64_t walGetOffset(SWal* pWal, int64_t ver) {*/
+  /*int code = walSeekVer(pWal, ver);*/
+  /*if(code != 0) {*/
+    /*return -1;*/
+  /*}*/
 
-  code = walValidateOffset(pWal, ver);
-  if(code != 0) {
-    return -1;
-  }
+  /*code = walValidateOffset(pWal, ver);*/
+  /*if(code != 0) {*/
+    /*return -1;*/
+  /*}*/
 
-  return 0;
-}
+  /*return 0;*/
+/*}*/
 
 #if 0
 static int32_t walSkipCorruptedRecord(SWal *pWal, SWalHead *pHead, int64_t tfd, int64_t *offset) {
diff --git a/source/libs/wal/test/walMetaTest.cpp b/source/libs/wal/test/walMetaTest.cpp
index c81343d03b..504f1ada3f 100644
--- a/source/libs/wal/test/walMetaTest.cpp
+++ b/source/libs/wal/test/walMetaTest.cpp
@@ -24,7 +24,7 @@ class WalCleanEnv : public ::testing::Test {
       pCfg->segSize = -1;
       pCfg->retentionPeriod = 0;
       pCfg->retentionSize = 0;
-      pCfg->walLevel = TAOS_WAL_FSYNC;
+      pCfg->level = TAOS_WAL_FSYNC;
       pWal = walOpen(pathName, pCfg);
       free(pCfg);
       ASSERT(pWal != NULL);
@@ -56,7 +56,7 @@ class WalCleanDeleteEnv : public ::testing::Test {
       memset(pCfg, 0, sizeof(SWalCfg));
       pCfg->retentionPeriod = 0;
       pCfg->retentionSize = 0;
-      pCfg->walLevel = TAOS_WAL_FSYNC;
+      pCfg->level = TAOS_WAL_FSYNC;
       pWal = walOpen(pathName, pCfg);
       free(pCfg);
       ASSERT(pWal != NULL);
@@ -95,7 +95,7 @@ class WalKeepEnv : public ::testing::Test {
       pCfg->segSize = -1;
       pCfg->retentionPeriod = 0;
       pCfg->retentionSize = 0;
-      pCfg->walLevel = TAOS_WAL_FSYNC;
+      pCfg->level = TAOS_WAL_FSYNC;
       pWal = walOpen(pathName, pCfg);
       free(pCfg);
       ASSERT(pWal != NULL);
@@ -164,18 +164,18 @@ TEST_F(WalKeepEnv, readOldMeta) {
   for(int i = 0; i < 10; i++) {
     code = walWrite(pWal, i, i+1, (void*)ranStr, len); 
     ASSERT_EQ(code, 0);
-    ASSERT_EQ(pWal->lastVersion, i);
+    ASSERT_EQ(pWal->vers.lastVer, i);
     code = walWrite(pWal, i+2, i, (void*)ranStr, len);
     ASSERT_EQ(code, -1);
-    ASSERT_EQ(pWal->lastVersion, i);
+    ASSERT_EQ(pWal->vers.lastVer, i);
   }
   char* oldss = walMetaSerialize(pWal);
 
   TearDown();
   SetUp();
 
-  ASSERT_EQ(pWal->firstVersion, 0);
-  ASSERT_EQ(pWal->lastVersion, 9);
+  ASSERT_EQ(pWal->vers.firstVer, 0);
+  ASSERT_EQ(pWal->vers.lastVer, 9);
 
   char* newss = walMetaSerialize(pWal);
 
@@ -195,10 +195,10 @@ TEST_F(WalCleanEnv, write) {
   for(int i = 0; i < 10; i++) {
     code = walWrite(pWal, i, i+1, (void*)ranStr, len); 
     ASSERT_EQ(code, 0);
-    ASSERT_EQ(pWal->lastVersion, i);
+    ASSERT_EQ(pWal->vers.lastVer, i);
     code = walWrite(pWal, i+2, i, (void*)ranStr, len);
     ASSERT_EQ(code, -1);
-    ASSERT_EQ(pWal->lastVersion, i);
+    ASSERT_EQ(pWal->vers.lastVer, i);
   }
   code = walWriteMeta(pWal);
   ASSERT_EQ(code, 0);
@@ -211,14 +211,14 @@ TEST_F(WalCleanEnv, rollback) {
   for(int i = 0; i < 10; i++) {
     code = walWrite(pWal, i, i+1, (void*)ranStr, len); 
     ASSERT_EQ(code, 0);
-    ASSERT_EQ(pWal->lastVersion, i);
+    ASSERT_EQ(pWal->vers.lastVer, i);
   }
   code = walRollback(pWal, 5);
   ASSERT_EQ(code, 0);
-  ASSERT_EQ(pWal->lastVersion, 4);
+  ASSERT_EQ(pWal->vers.lastVer, 4);
   code = walRollback(pWal, 3);
   ASSERT_EQ(code, 0);
-  ASSERT_EQ(pWal->lastVersion, 2);
+  ASSERT_EQ(pWal->vers.lastVer, 2);
   code = walWriteMeta(pWal);
   ASSERT_EQ(code, 0);
 }
@@ -231,16 +231,16 @@ TEST_F(WalCleanDeleteEnv, roll) {
   for(i = 0; i < 100; i++) {
     code = walWrite(pWal, i, 0, (void*)ranStr, len);
     ASSERT_EQ(code, 0);
-    ASSERT_EQ(pWal->lastVersion, i);
+    ASSERT_EQ(pWal->vers.lastVer, i);
     code = walCommit(pWal, i);
-    ASSERT_EQ(pWal->commitVersion, i);
+    ASSERT_EQ(pWal->vers.commitVer, i);
   }
 
   walBeginTakeSnapshot(pWal, i-1);
-  ASSERT_EQ(pWal->snapshottingVer, i-1); 
+  ASSERT_EQ(pWal->vers.verInSnapshotting, i-1);
   walEndTakeSnapshot(pWal);
-  ASSERT_EQ(pWal->snapshotVersion, i-1); 
-  ASSERT_EQ(pWal->snapshottingVer, -1); 
+  ASSERT_EQ(pWal->vers.snapshotVer, i-1);
+  ASSERT_EQ(pWal->vers.verInSnapshotting, -1);
 
   code = walWrite(pWal, 5, 0, (void*)ranStr, len);
   ASSERT_NE(code, 0);
@@ -249,7 +249,7 @@ TEST_F(WalCleanDeleteEnv, roll) {
     code = walWrite(pWal, i, 0, (void*)ranStr, len);
     ASSERT_EQ(code, 0);
     code = walCommit(pWal, i);
-    ASSERT_EQ(pWal->commitVersion, i);
+    ASSERT_EQ(pWal->vers.commitVer, i);
   }
 
   //code = walWriteMeta(pWal);
diff --git a/source/util/src/tarray.c b/source/util/src/tarray.c
index 6216188496..581a797343 100644
--- a/source/util/src/tarray.c
+++ b/source/util/src/tarray.c
@@ -250,7 +250,7 @@ void taosArrayPopFrontBatch(SArray* pArray, size_t cnt) {
   if(pArray->size == 0) {
     return;
   }
-  memmove(pArray->pData, (char*)pArray->pData + cnt * pArray->elemSize, pArray->size);
+  memmove(pArray->pData, (char*)pArray->pData + cnt * pArray->elemSize, pArray->size * pArray->elemSize);
 }
 
 void taosArrayPopTailBatch(SArray* pArray, size_t cnt) {