diff --git a/CMakeLists.txt b/CMakeLists.txt
index e53cca2ea8..500b2ff1eb 100755
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,7 +1,6 @@
 CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
 PROJECT(TDengine)
 
-SET(TD_SYNC FALSE)
 SET(TD_ACCOUNT FALSE)
 SET(TD_ADMIN FALSE)
 SET(TD_GRANT FALSE)
diff --git a/cmake/define.inc b/cmake/define.inc
index 93bf602610..d68f2230f1 100755
--- a/cmake/define.inc
+++ b/cmake/define.inc
@@ -1,10 +1,6 @@
 CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
 PROJECT(TDengine)
 
-IF (TD_SYNC)
-  ADD_DEFINITIONS(-D_SYNC)
-ENDIF ()
-
 IF (TD_ACCOUNT)
   ADD_DEFINITIONS(-D_ACCT)
 ENDIF ()
diff --git a/cmake/env.inc b/cmake/env.inc
index fbfa40e5ae..67b934119d 100755
--- a/cmake/env.inc
+++ b/cmake/env.inc
@@ -9,7 +9,6 @@ SET(LIBRARY_OUTPUT_PATH ${PROJECT_BINARY_DIR}/build/lib)
 SET(EXECUTABLE_OUTPUT_PATH ${PROJECT_BINARY_DIR}/build/bin)
 SET(TD_TESTS_OUTPUT_DIR ${PROJECT_BINARY_DIR}/test)
 
-MESSAGE(STATUS "Operating system dependency directory: " ${TD_OS_DIR})
 MESSAGE(STATUS "Project source directory: " ${PROJECT_SOURCE_DIR})
 MESSAGE(STATUS "Project binary files output path: " ${PROJECT_BINARY_DIR})
 MESSAGE(STATUS "Project executable files output path: " ${EXECUTABLE_OUTPUT_PATH})
diff --git a/cmake/platform.inc b/cmake/platform.inc
index 2e0e2d6af0..7a371df70b 100755
--- a/cmake/platform.inc
+++ b/cmake/platform.inc
@@ -33,20 +33,23 @@ IF (${CPUTYPE} MATCHES "aarch32")
   SET(TD_PAGMODE_LITE TRUE)
   ADD_DEFINITIONS(-D_TD_ARM_)
   ADD_DEFINITIONS(-D_TD_ARM_32_)
+  MESSAGE(STATUS "input cpuType: aarch32")
 ELSEIF (${CPUTYPE} MATCHES "aarch64")
   SET(TD_ARM TRUE)
   SET(TD_ARM_64 TRUE)
   ADD_DEFINITIONS(-D_TD_ARM_)
   ADD_DEFINITIONS(-D_TD_ARM_64_)
+   MESSAGE(STATUS "input cpuType: aarch64")
 ELSEIF (${CPUTYPE} MATCHES "mips64")
   SET(TD_MIPS TRUE)
   SET(TD_MIPS_64 TRUE)
   ADD_DEFINITIONS(-D_TD_MIPS_)
   ADD_DEFINITIONS(-D_TD_MIPS_64_)
+  MESSAGE(STATUS "input cpuType: mips64")
 ELSEIF (${CPUTYPE} MATCHES "x64")
-  MESSAGE(STATUS "input cpuType: " ${CPUTYPE})
+  MESSAGE(STATUS "input cpuType: x64")
 ELSEIF (${CPUTYPE} MATCHES "x86")
-  MESSAGE(STATUS "input cpuType: " ${CPUTYPE})
+  MESSAGE(STATUS "input cpuType: x86")
 ELSE ()
   MESSAGE(STATUS "input cpuType: " ${CPUTYPE})
 ENDIF ()
@@ -61,13 +64,13 @@ MESSAGE(STATUS "The current os is " ${TD_OS_INFO})
 IF (${CMAKE_SYSTEM_NAME} MATCHES "Linux")
   IF (${CMAKE_SIZEOF_VOID_P} MATCHES 8)
     SET(TD_LINUX_64 TRUE)
-    SET(TD_OS_DIR ${TD_COMMUNITY_DIR}/src/os/linux)
     ADD_DEFINITIONS(-D_M_X64)
+    ADD_DEFINITIONS(-D_TD_LINUX_64)
     MESSAGE(STATUS "The current platform is Linux 64-bit")
   ELSEIF (${CMAKE_SIZEOF_VOID_P} MATCHES 4)
+    SET(TD_LINUX_32 TRUE)
+    ADD_DEFINITIONS(-D_TD_LINUX_32)
     IF (TD_ARM)
-      SET(TD_LINUX_32 TRUE)
-      SET(TD_OS_DIR ${TD_COMMUNITY_DIR}/src/os/linux)
       #ADD_DEFINITIONS(-D_M_IX86)
       MESSAGE(STATUS "The current platform is Linux 32-bit")
     ELSE ()
@@ -81,7 +84,7 @@ IF (${CMAKE_SYSTEM_NAME} MATCHES "Linux")
 ELSEIF (${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
   IF (${CMAKE_SIZEOF_VOID_P} MATCHES 8)
     SET(TD_DARWIN_64 TRUE)
-    SET(TD_OS_DIR ${TD_COMMUNITY_DIR}/src/os/darwin)
+    ADD_DEFINITIONS(-D_TD_DARWIN_64)
     MESSAGE(STATUS "The current platform is Darwin 64-bit")
   ELSE ()
     MESSAGE(FATAL_ERROR "The current platform is Darwin 32-bit, not supported yet")
@@ -90,10 +93,12 @@ ELSEIF (${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
 ELSEIF (${CMAKE_SYSTEM_NAME} MATCHES "Windows")
   IF (${CMAKE_SIZEOF_VOID_P} MATCHES 8)
     SET(TD_WINDOWS_64 TRUE)
-    SET(TD_OS_DIR ${TD_COMMUNITY_DIR}/src/os/windows)
     ADD_DEFINITIONS(-D_M_X64)
+    ADD_DEFINITIONS(-D_TD_WINDOWS_64)
     MESSAGE(STATUS "The current platform is Windows 64-bit")
   ELSE ()
+    SET(TD_WINDOWS_32 TRUE)
+    ADD_DEFINITIONS(-D_TD_WINDOWS_32)
     MESSAGE(FATAL_ERROR "The current platform is Windows 32-bit, not supported yet")
     EXIT ()
   ENDIF ()
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 57d7234379..ede66d95bb 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -10,6 +10,8 @@ ADD_SUBDIRECTORY(client)
 ADD_SUBDIRECTORY(query)
 ADD_SUBDIRECTORY(kit)
 ADD_SUBDIRECTORY(plugins)
+ADD_SUBDIRECTORY(sync)
+ADD_SUBDIRECTORY(balance)
 ADD_SUBDIRECTORY(mnode)
 ADD_SUBDIRECTORY(vnode)
 ADD_SUBDIRECTORY(tsdb)
diff --git a/src/balance/CMakeLists.txt b/src/balance/CMakeLists.txt
new file mode 100644
index 0000000000..45b7c4ed57
--- /dev/null
+++ b/src/balance/CMakeLists.txt
@@ -0,0 +1,16 @@
+CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
+PROJECT(TDengine)
+
+IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
+  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
+  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
+  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/common/inc)
+  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/mnode/inc)
+  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/dnode/inc)
+  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/sdb/inc)
+  INCLUDE_DIRECTORIES(${TD_ENTERPRISE_DIR}/src/inc)
+  INCLUDE_DIRECTORIES(inc)
+  AUX_SOURCE_DIRECTORY(src SRC)
+  ADD_LIBRARY(balance ${SRC})
+ENDIF ()
diff --git a/src/balance/src/balance.c b/src/balance/src/balance.c
new file mode 100644
index 0000000000..3ef616bff0
--- /dev/null
+++ b/src/balance/src/balance.c
@@ -0,0 +1,1006 @@
+/*
+ * 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 "tutil.h"
+#include "tbalance.h"
+#include "tsync.h"
+#include "ttime.h"
+#include "ttimer.h"
+#include "tglobal.h"
+#include "tdataformat.h"
+#include "dnode.h"
+#include "mnode.h"
+#include "mnodeDef.h"
+#include "mnodeInt.h"
+#include "mnodeDnode.h"
+#include "mnodeDb.h"
+#include "mnodeMnode.h"
+#include "mnodeSdb.h"
+#include "mnodeShow.h"
+#include "mnodeUser.h"
+#include "mnodeVgroup.h"
+
+/*
+ * once sdb work as mater, then tsAccessSquence reset to zero
+ * increase tsAccessSquence every balance interval
+ */
+extern void *       tsMnodeTmr;
+static void *       tsBalanceTimer = NULL;
+static int32_t      tsBalanceDnodeListSize = 0;
+static SDnodeObj ** tsBalanceDnodeList = NULL;
+static int32_t      tsBalanceDnodeListMallocSize = 16;
+static pthread_mutex_t tsBalanceMutex;
+
+static void  balanceStartTimer(int64_t mseconds);
+static void  balanceInitDnodeList();
+static void  balanceCleanupDnodeList();
+static void  balanceAccquireDnodeList();
+static void  balanceReleaseDnodeList();
+static void  balanceMonitorDnodeModule();
+static float balanceTryCalcDnodeScore(SDnodeObj *pDnode, int32_t extraVnode);
+static int32_t balanceGetScoresMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn);
+static int32_t balanceRetrieveScores(SShowObj *pShow, char *data, int32_t rows, void *pConn);
+
+static void balanceLock() {
+  pthread_mutex_lock(&tsBalanceMutex);
+}
+
+static void balanceUnLock() {
+  pthread_mutex_unlock(&tsBalanceMutex);
+}
+
+static bool balanceCheckFree(SDnodeObj *pDnode) {
+  if (pDnode->status == TAOS_DN_STATUS_DROPPING || pDnode->status == TAOS_DN_STATUS_OFFLINE) {
+    mError("dnode:%d, status:%s not available", pDnode->dnodeId, mnodeGetDnodeStatusStr(pDnode->status));
+    return false;
+  }
+  
+  if (pDnode->openVnodes >= TSDB_MAX_VNODES) {
+    mError("dnode:%d, openVnodes:%d maxVnodes:%d not available", pDnode->dnodeId, pDnode->openVnodes, TSDB_MAX_VNODES);
+    return false;
+  }
+
+  if (pDnode->diskAvailable <= tsMinimalDataDirGB) {
+    mError("dnode:%d, disk space:%fGB, not available", pDnode->dnodeId, pDnode->diskAvailable);
+    return false;
+  }
+
+  if (pDnode->alternativeRole == TAOS_DN_ALTERNATIVE_ROLE_MNODE) {
+    mDebug("dnode:%d, alternative role is master, can't alloc vnodes in this dnode", pDnode->dnodeId);
+    return false;
+  }
+
+  return true;
+}
+
+static void balanceDiscardVnode(SVgObj *pVgroup, SVnodeGid *pVnodeGid) {
+  mDebug("vgId:%d, dnode:%d is dropping", pVgroup->vgId, pVnodeGid->dnodeId);
+
+  SDnodeObj *pDnode = mnodeGetDnode(pVnodeGid->dnodeId);
+  if (pDnode != NULL) {
+    atomic_sub_fetch_32(&pDnode->openVnodes, 1);
+    mnodeDecDnodeRef(pDnode);
+  }
+
+  SVnodeGid vnodeGid[TSDB_MAX_REPLICA]; memset(vnodeGid, 0, sizeof(vnodeGid)); /* = {0}; */
+  int32_t   numOfVnodes = 0;
+  for (int32_t i = 0; i < pVgroup->numOfVnodes; ++i) {
+    SVnodeGid *pTmpVodeGid = pVgroup->vnodeGid + i;
+    if (pTmpVodeGid == pVnodeGid) {
+      continue;
+    }
+    vnodeGid[numOfVnodes] = *pTmpVodeGid;
+    ++numOfVnodes;
+  }
+  memcpy(pVgroup->vnodeGid, vnodeGid, TSDB_MAX_REPLICA * sizeof(SVnodeGid));
+  pVgroup->numOfVnodes = numOfVnodes;
+
+  mnodeUpdateVgroup(pVgroup);
+}
+
+static void balanceSwapVnodeGid(SVnodeGid *pVnodeGid1, SVnodeGid *pVnodeGid2) {
+  // SVnodeGid tmp = *pVnodeGid1;
+  // *pVnodeGid1 = *pVnodeGid2;
+  // *pVnodeGid2 = tmp;
+}
+
+int32_t balanceAllocVnodes(SVgObj *pVgroup) {
+  int32_t dnode = 0;
+  int32_t vnodes = 0;
+
+  balanceLock();
+
+  balanceAccquireDnodeList();
+
+  for (int32_t i = 0; i < pVgroup->numOfVnodes; ++i) {
+    for (; dnode < tsBalanceDnodeListSize; ++dnode) {
+      SDnodeObj *pDnode = tsBalanceDnodeList[dnode];
+      if (balanceCheckFree(pDnode)) {
+        SVnodeGid *pVnodeGid = pVgroup->vnodeGid + i;
+        pVnodeGid->dnodeId = pDnode->dnodeId;
+        pVnodeGid->pDnode = pDnode;
+        dnode++;
+        vnodes++;
+        break;
+      }
+    }
+  }
+
+  if (vnodes != pVgroup->numOfVnodes) {
+    mDebug("vgId:%d, db:%s need vnodes:%d, but alloc:%d, free them", pVgroup->vgId, pVgroup->dbName,
+           pVgroup->numOfVnodes, vnodes);
+    balanceReleaseDnodeList();       
+    balanceUnLock();
+    return -1;
+  }
+
+  /*
+   * make the choice more random.
+   * replica 1: no choice
+   * replica 2: there are 2 combinations
+   * replica 3 or larger: there are 6 combinations
+   */
+  if (pVgroup->numOfVnodes == 1) {
+  } else if (pVgroup->numOfVnodes == 2) {
+    if (rand() % 2 == 0) {
+      balanceSwapVnodeGid(pVgroup->vnodeGid, pVgroup->vnodeGid + 1);
+    }
+  } else {
+    int32_t randVal = rand() % 6;
+    if (randVal == 1) {  // 1, 0, 2
+      balanceSwapVnodeGid(pVgroup->vnodeGid + 0, pVgroup->vnodeGid + 1);
+    } else if (randVal == 2) {  // 1, 2, 0
+      balanceSwapVnodeGid(pVgroup->vnodeGid + 0, pVgroup->vnodeGid + 1);
+      balanceSwapVnodeGid(pVgroup->vnodeGid + 1, pVgroup->vnodeGid + 2);
+    } else if (randVal == 3) {  // 2, 1, 0
+      balanceSwapVnodeGid(pVgroup->vnodeGid + 0, pVgroup->vnodeGid + 2);
+    } else if (randVal == 4) {  // 2, 0, 1
+      balanceSwapVnodeGid(pVgroup->vnodeGid + 0, pVgroup->vnodeGid + 2);
+      balanceSwapVnodeGid(pVgroup->vnodeGid + 1, pVgroup->vnodeGid + 2);
+    }
+    if (randVal == 5) {  // 0, 2, 1
+      balanceSwapVnodeGid(pVgroup->vnodeGid + 1, pVgroup->vnodeGid + 2);
+    } else {
+    }  // 0, 1, 2
+  }
+
+  balanceReleaseDnodeList();
+  balanceUnLock();
+  return 0;
+}
+
+static bool balanceCheckVgroupReady(SVgObj *pVgroup, SVnodeGid *pRmVnode) {
+  if (pVgroup->lbTime + 5 * tsStatusInterval > tsAccessSquence) {
+    return false;
+  }
+
+  bool isReady = false;
+  for (int32_t i = 0; i < pVgroup->numOfVnodes; ++i) {
+    SVnodeGid *pVnode = pVgroup->vnodeGid + i;
+    if (pVnode == pRmVnode) continue;
+
+    mTrace("vgId:%d, change vgroup status, dnode:%d status:%d", pVgroup->vgId, pVnode->pDnode->dnodeId,
+           pVnode->pDnode->status);
+    if (pVnode->pDnode->status == TAOS_DN_STATUS_DROPPING) continue;
+    if (pVnode->pDnode->status == TAOS_DN_STATUS_OFFLINE) continue;
+
+    if (pVnode->role == TAOS_SYNC_ROLE_SLAVE || pVnode->role == TAOS_SYNC_ROLE_MASTER) {
+      isReady = true;
+    }
+  }
+
+  return isReady;
+}
+
+/**
+ * desc: remove one vnode from vgroup
+ * all vnodes in vgroup should in ready state, except the balancing one
+ **/
+static void balanceRemoveVnode(SVgObj *pVgroup) {
+  if (pVgroup->numOfVnodes <= 1) return;
+
+  SVnodeGid *pRmVnode = NULL;
+  SVnodeGid *pSelVnode = NULL;
+  int32_t    maxScore = 0;
+
+  for (int32_t i = 0; i < pVgroup->numOfVnodes; ++i) {
+    SVnodeGid *pVnode = &(pVgroup->vnodeGid[i]);
+    SDnodeObj *pDnode = mnodeGetDnode(pVnode->dnodeId);
+
+    if (pDnode == NULL) {
+      mError("vgId:%d, dnode:%d not exist, remove it", pVgroup->vgId, pVnode->dnodeId);
+      pRmVnode = pVnode;
+      break;
+    }
+
+    if (pDnode->status == TAOS_DN_STATUS_DROPPING) {
+      mDebug("vgId:%d, dnode:%d in dropping state", pVgroup->vgId, pVnode->dnodeId);
+      pRmVnode = pVnode;
+    } else if (pVnode->dnodeId == pVgroup->lbDnodeId) {
+      mDebug("vgId:%d, dnode:%d in updating state", pVgroup->vgId, pVnode->dnodeId);
+      pRmVnode = pVnode;
+    } else {
+      if (pSelVnode == NULL) {
+        pSelVnode = pVnode;
+        maxScore = pDnode->score;
+      } else {
+        if (maxScore < pDnode->score) {
+          pSelVnode = pVnode;
+          maxScore = pDnode->score;
+        }
+      }
+    }
+
+    mnodeDecDnodeRef(pDnode);
+  }
+
+  if (pRmVnode != NULL) {
+    pSelVnode = pRmVnode;
+  }
+
+  if (!balanceCheckVgroupReady(pVgroup, pSelVnode)) {
+    mDebug("vgId:%d, is not ready", pVgroup->vgId);
+  } else {
+    mDebug("vgId:%d, is ready, discard dnode:%d", pVgroup->vgId, pSelVnode->dnodeId);
+    balanceDiscardVnode(pVgroup, pSelVnode);
+  }
+}
+
+static bool balanceCheckDnodeInVgroup(SDnodeObj *pDnode, SVgObj *pVgroup) {
+ for (int32_t i = 0; i < pVgroup->numOfVnodes; ++i) {
+    SVnodeGid *pGid = &pVgroup->vnodeGid[i];
+    if (pGid->dnodeId == 0) break;
+    if (pGid->dnodeId == pDnode->dnodeId) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+/**
+ * desc: add vnode to vgroup, find a new one if dest dnode is null
+ **/
+static int32_t balanceAddVnode(SVgObj *pVgroup, SDnodeObj *pSrcDnode, SDnodeObj *pDestDnode) {
+  if (pDestDnode == NULL) {
+    for (int32_t i = 0; i < tsBalanceDnodeListSize; ++i) {
+      SDnodeObj *pDnode = tsBalanceDnodeList[i];
+      if (pDnode == pSrcDnode) continue;
+      if (balanceCheckDnodeInVgroup(pDnode, pVgroup)) continue;
+      if (!balanceCheckFree(pDnode)) continue;
+      
+      pDestDnode = pDnode;
+      mDebug("vgId:%d, add vnode to dnode:%d", pVgroup->vgId, pDnode->dnodeId);
+      break;
+    }
+  }
+
+  if (pDestDnode == NULL) {
+    return TSDB_CODE_MND_DNODE_NOT_EXIST;
+  }
+
+  SVnodeGid *pVnodeGid = pVgroup->vnodeGid + pVgroup->numOfVnodes;
+  pVnodeGid->dnodeId = pDestDnode->dnodeId;
+  pVnodeGid->pDnode = pDestDnode;
+  pVgroup->numOfVnodes++;
+
+  if (pSrcDnode != NULL) {
+    pVgroup->lbDnodeId = pSrcDnode->dnodeId;
+  }
+
+  atomic_add_fetch_32(&pDestDnode->openVnodes, 1);
+
+  mnodeUpdateVgroup(pVgroup);
+
+  return TSDB_CODE_SUCCESS;
+}
+
+static bool balanceMonitorBalance() {
+  if (tsBalanceDnodeListSize < 2) return false;
+
+  for (int32_t src = tsBalanceDnodeListSize - 1; src >= 0; --src) {
+    SDnodeObj *pDnode = tsBalanceDnodeList[src];
+    mDebug("%d-dnode:%d, state:%s, score:%.1f, numOfCores:%d, openVnodes:%d", tsBalanceDnodeListSize - src - 1,
+           pDnode->dnodeId, mnodeGetDnodeStatusStr(pDnode->status), pDnode->score, pDnode->numOfCores,
+           pDnode->openVnodes);
+  }
+
+  float scoresDiff = tsBalanceDnodeList[tsBalanceDnodeListSize - 1]->score - tsBalanceDnodeList[0]->score;
+  if (scoresDiff < 0.01) {
+    mDebug("all dnodes:%d is already balanced, scoresDiff:%f", tsBalanceDnodeListSize, scoresDiff);
+    return false;
+  }
+
+  for (int32_t src = tsBalanceDnodeListSize - 1; src > 0; --src) {
+    SDnodeObj *pSrcDnode = tsBalanceDnodeList[src];
+    float srcScore = balanceTryCalcDnodeScore(pSrcDnode, -1);
+    if (tsEnableBalance == 0 && pSrcDnode->status != TAOS_DN_STATUS_DROPPING) {
+      continue;
+    }
+
+    void *pIter = NULL;
+    while (1) {
+      SVgObj *pVgroup;
+      pIter = mnodeGetNextVgroup(pIter, &pVgroup);
+      if (pVgroup == NULL) break;
+
+      if (balanceCheckDnodeInVgroup(pSrcDnode, pVgroup)) {
+        for (int32_t dest = 0; dest < src; dest++) {
+          SDnodeObj *pDestDnode = tsBalanceDnodeList[dest];
+          if (balanceCheckDnodeInVgroup(pDestDnode, pVgroup)) continue;
+
+          float destScore = balanceTryCalcDnodeScore(pDestDnode, 1);
+          if (srcScore + 0.0001 < destScore) continue;
+          if (!balanceCheckFree(pDestDnode)) continue;
+          
+          mDebug("vgId:%d, balance from dnode:%d to dnode:%d, srcScore:%.1f:%.1f, destScore:%.1f:%.1f",
+                 pVgroup->vgId, pSrcDnode->dnodeId, pDestDnode->dnodeId, pSrcDnode->score,
+                 srcScore, pDestDnode->score, destScore);
+          balanceAddVnode(pVgroup, pSrcDnode, pDestDnode);
+          mnodeDecVgroupRef(pVgroup);
+          sdbFreeIter(pIter);
+          return true;
+        }
+      }
+
+      mnodeDecVgroupRef(pVgroup);
+    }
+
+    sdbFreeIter(pIter);
+  }
+
+  return false;
+}
+
+// if mgmt changed to master
+// 1. reset balanceAccessSquence to zero
+// 2. reset state of dnodes to offline
+// 3. reset lastAccess of dnodes to zero
+void balanceReset() {
+  void *     pIter = NULL;
+  SDnodeObj *pDnode = NULL;
+  while (1) {
+    pIter = mnodeGetNextDnode(pIter, &pDnode);
+    if (pDnode == NULL) break;
+
+    // while master change, should reset dnode to offline
+    mInfo("dnode:%d set access:%d to 0", pDnode->dnodeId, pDnode->lastAccess);
+    pDnode->lastAccess = 0;
+    if (pDnode->status != TAOS_DN_STATUS_DROPPING) {
+      pDnode->status = TAOS_DN_STATUS_OFFLINE;
+    }
+
+    mnodeDecDnodeRef(pDnode);
+  }
+
+  sdbFreeIter(pIter);
+
+  tsAccessSquence = 0;
+}
+
+static int32_t balanceMonitorVgroups() {
+  void *  pIter = NULL;
+  SVgObj *pVgroup = NULL;
+  bool    hasUpdatingVgroup = false;
+
+  while (1) {
+    pIter = mnodeGetNextVgroup(pIter, &pVgroup);
+    if (pVgroup == NULL) break;
+
+    int32_t dbReplica = pVgroup->pDb->cfg.replications;
+    int32_t vgReplica = pVgroup->numOfVnodes;
+    
+    if (vgReplica > dbReplica) {
+      mInfo("vgId:%d, replica:%d numOfVnodes:%d, try remove one vnode", pVgroup->vgId, dbReplica, vgReplica);
+      hasUpdatingVgroup = true;
+      balanceRemoveVnode(pVgroup);
+    } else if (vgReplica < dbReplica) {
+      mInfo("vgId:%d, replica:%d numOfVnodes:%d, try add one vnode", pVgroup->vgId, dbReplica, vgReplica);
+      hasUpdatingVgroup = true;
+      balanceAddVnode(pVgroup, NULL, NULL);
+    }
+
+    mnodeDecVgroupRef(pVgroup);
+  }
+
+  sdbFreeIter(pIter);
+
+  return hasUpdatingVgroup;
+}
+
+static bool balanceMonitorDnodeDropping(SDnodeObj *pDnode) {
+  mDebug("dnode:%d, in dropping state", pDnode->dnodeId);
+
+  void *  pIter = NULL;
+  bool    hasThisDnode = false;
+  while (1) {
+    SVgObj *pVgroup = NULL;
+    pIter = mnodeGetNextVgroup(pIter, &pVgroup);
+    if (pVgroup == NULL) break;
+
+    hasThisDnode = balanceCheckDnodeInVgroup(pDnode, pVgroup);
+    mnodeDecVgroupRef(pVgroup);
+
+    if (hasThisDnode) break;
+  }
+
+  sdbFreeIter(pIter);
+
+  if (!hasThisDnode) {
+    mInfo("dnode:%d, dropped for all vnodes are moving to other dnodes", pDnode->dnodeId);
+    mnodeDropDnode(pDnode, NULL);
+    return true;
+  }
+
+  return false;
+}
+
+static bool balanceMontiorDropping() {
+  void *pIter = NULL;
+  SDnodeObj *pDnode = NULL;
+
+  while (1) {
+    mnodeDecDnodeRef(pDnode);
+    pIter = mnodeGetNextDnode(pIter, &pDnode);
+    if (pDnode == NULL) break;
+
+    if (pDnode->status == TAOS_DN_STATUS_OFFLINE) {
+      if (pDnode->lastAccess + tsOfflineThreshold > tsAccessSquence) continue;
+      if (strcmp(pDnode->dnodeEp, dnodeGetMnodeMasterEp()) == 0) continue; 
+      if (mnodeGetDnodesNum() <= 1) continue;
+
+      mLInfo("dnode:%d, set to removing state for it offline:%d seconds", pDnode->dnodeId,
+              tsAccessSquence - pDnode->lastAccess);
+
+      pDnode->status = TAOS_DN_STATUS_DROPPING;
+      mnodeUpdateDnode(pDnode);
+      mnodeDecDnodeRef(pDnode);
+      sdbFreeIter(pIter);
+      return true;
+    }
+
+    if (pDnode->status == TAOS_DN_STATUS_DROPPING) {
+      bool ret = balanceMonitorDnodeDropping(pDnode);
+      mnodeDecDnodeRef(pDnode);
+      sdbFreeIter(pIter);
+      return ret;
+    }
+  }
+
+  sdbFreeIter(pIter);
+
+  return false;
+}
+
+static bool balanceStart() {
+  if (!sdbIsMaster()) return false;
+
+  balanceLock();
+
+  balanceAccquireDnodeList();
+
+  balanceMonitorDnodeModule();
+
+  bool updateSoon = balanceMontiorDropping();
+
+  if (!updateSoon) {
+    updateSoon = balanceMonitorVgroups();
+  }
+
+  if (!updateSoon) {
+    updateSoon = balanceMonitorBalance();
+  }
+ 
+  balanceReleaseDnodeList();
+
+  balanceUnLock();
+
+  return updateSoon;
+}
+
+static void balanceSetVgroupOffline(SDnodeObj* pDnode) {
+  void *pIter = NULL;
+  while (1) {
+    SVgObj *pVgroup;
+    pIter = mnodeGetNextVgroup(pIter, &pVgroup);
+    if (pVgroup == NULL) break;
+
+    for (int32_t i = 0; i < pVgroup->numOfVnodes; ++i) {
+      if (pVgroup->vnodeGid[i].pDnode == pDnode) {
+        pVgroup->vnodeGid[i].role = TAOS_SYNC_ROLE_OFFLINE;
+      }
+    }
+    mnodeDecVgroupRef(pVgroup);
+  }
+
+  sdbFreeIter(pIter);
+}
+
+static void balanceCheckDnodeAccess() {
+  void *     pIter = NULL;
+  SDnodeObj *pDnode = NULL;
+
+  while (1) {
+    pIter = mnodeGetNextDnode(pIter, &pDnode);
+    if (pDnode == NULL) break;
+    if (tsAccessSquence - pDnode->lastAccess > 3) {
+      if (pDnode->status != TAOS_DN_STATUS_DROPPING && pDnode->status != TAOS_DN_STATUS_OFFLINE) {
+        pDnode->status = TAOS_DN_STATUS_OFFLINE;
+        mInfo("dnode:%d, set to offline state", pDnode->dnodeId);
+        balanceSetVgroupOffline(pDnode);
+      }
+    }
+    mnodeDecDnodeRef(pDnode);
+  }
+
+  sdbFreeIter(pIter);
+}
+
+static void balanceProcessBalanceTimer(void *handle, void *tmrId) {
+  if (!sdbIsMaster()) return;
+
+  tsBalanceTimer = NULL;
+  tsAccessSquence ++;
+
+  balanceCheckDnodeAccess();  
+  bool updateSoon = false;
+
+  if (handle == NULL) {
+    if (tsAccessSquence % tsBalanceInterval == 0) {
+      mDebug("balance function is scheduled by timer");
+      updateSoon = balanceStart();
+    }
+  } else {
+    int64_t mseconds = (int64_t)handle;
+    mDebug("balance function is scheduled by event for %" PRId64 " mseconds arrived", mseconds);
+    updateSoon = balanceStart();
+  }
+
+  if (updateSoon) {
+    balanceStartTimer(1000);
+  } else {
+    taosTmrReset(balanceProcessBalanceTimer, tsStatusInterval * 1000, NULL, tsMnodeTmr, &tsBalanceTimer);
+  }
+}
+
+static void balanceStartTimer(int64_t mseconds) {
+  taosTmrReset(balanceProcessBalanceTimer, mseconds, (void *)mseconds, tsMnodeTmr, &tsBalanceTimer);
+}
+
+void balanceSyncNotify() {
+  if (sdbIsMaster()) {
+    balanceLock();
+    balanceAccquireDnodeList();
+    balanceMonitorDnodeModule();
+    balanceReleaseDnodeList();
+    balanceUnLock();
+  }
+}
+
+void balanceAsyncNotify() {
+  balanceStartTimer(500); 
+}
+
+int32_t balanceInit() {
+  mnodeAddShowMetaHandle(TSDB_MGMT_TABLE_SCORES, balanceGetScoresMeta);
+  mnodeAddShowRetrieveHandle(TSDB_MGMT_TABLE_SCORES, balanceRetrieveScores);
+  
+  pthread_mutex_init(&tsBalanceMutex, NULL);
+  balanceInitDnodeList();
+  balanceStartTimer(2000);
+  mDebug("balance start fp:%p initialized", balanceProcessBalanceTimer);
+
+  balanceReset();
+  
+  return 0;
+}
+
+void balanceCleanUp() {
+  if (tsBalanceTimer != NULL) {
+    taosTmrStopA(&tsBalanceTimer);
+    pthread_mutex_destroy(&tsBalanceMutex);
+    tsBalanceTimer = NULL;
+    mDebug("stop balance timer");
+  }
+  balanceCleanupDnodeList();
+}
+
+int32_t balanceDropDnode(SDnodeObj *pDnode) {
+  int32_t    totalFreeVnodes = 0;
+  void *     pIter = NULL;
+  SDnodeObj *pTempDnode = NULL;
+
+  while (1) {
+    pIter = mnodeGetNextDnode(pIter, &pTempDnode);
+    if (pTempDnode == NULL) break;
+
+    if (pTempDnode != pDnode && balanceCheckFree(pTempDnode)) {
+      totalFreeVnodes += (TSDB_MAX_VNODES - pTempDnode->openVnodes);
+    }
+
+    mnodeDecDnodeRef(pTempDnode);
+  }
+
+  sdbFreeIter(pIter);
+
+  if (pDnode->openVnodes > totalFreeVnodes) {
+    mError("dnode:%d, openVnodes:%d totalFreeVnodes:%d no enough dnodes", pDnode->dnodeId, pDnode->openVnodes, totalFreeVnodes);
+    return TSDB_CODE_MND_NO_ENOUGH_DNODES;
+  }
+
+  pDnode->status = TAOS_DN_STATUS_DROPPING;
+  mnodeUpdateDnode(pDnode);
+  
+  balanceStartTimer(1100);
+
+  return TSDB_CODE_SUCCESS;
+}
+
+static int32_t balanceCalcCpuScore(SDnodeObj *pDnode) {
+  if (pDnode->cpuAvgUsage < 80)
+    return 0;
+  else if (pDnode->cpuAvgUsage < 90)
+    return 10;
+  else
+    return 50;
+}
+
+static int32_t balanceCalcMemoryScore(SDnodeObj *pDnode) {
+  if (pDnode->memoryAvgUsage < 80)
+    return 0;
+  else if (pDnode->memoryAvgUsage < 90)
+    return 10;
+  else
+    return 50;
+}
+
+static int32_t balanceCalcDiskScore(SDnodeObj *pDnode) {
+  if (pDnode->diskAvgUsage < 80)
+    return 0;
+  else if (pDnode->diskAvgUsage < 90)
+    return 10;
+  else
+    return 50;
+}
+
+static int32_t balanceCalcBandwidthScore(SDnodeObj *pDnode) {
+  if (pDnode->bandwidthUsage < 30)
+    return 0;
+  else if (pDnode->bandwidthUsage < 80)
+    return 10;
+  else
+    return 50;
+}
+
+static float balanceCalcModuleScore(SDnodeObj *pDnode) {
+  if (pDnode->numOfCores <= 0) return 0;
+  if (pDnode->isMgmt) {
+     return (float)tsMnodeEqualVnodeNum / pDnode->numOfCores;
+  }
+  return 0;
+}
+
+static float balanceCalcVnodeScore(SDnodeObj *pDnode, int32_t extra) {
+  if (pDnode->status == TAOS_DN_STATUS_DROPPING || pDnode->status == TAOS_DN_STATUS_OFFLINE) return 100000000;
+  if (pDnode->numOfCores <= 0) return 0;
+  return (float)(pDnode->openVnodes + extra) / pDnode->numOfCores;
+}
+
+/**
+ * calc singe score, such as cpu/memory/disk/bandwitdh/vnode
+ * 1. get the score config
+ * 2. if the value is out of range, use border data
+ * 3. otherwise use interpolation method
+ **/
+void balanceCalcDnodeScore(SDnodeObj *pDnode) {
+  pDnode->score = balanceCalcCpuScore(pDnode) + balanceCalcMemoryScore(pDnode) + balanceCalcDiskScore(pDnode) +
+                  balanceCalcBandwidthScore(pDnode) + balanceCalcModuleScore(pDnode) +
+                  balanceCalcVnodeScore(pDnode, 0) + pDnode->customScore;
+}
+
+float balanceTryCalcDnodeScore(SDnodeObj *pDnode, int32_t extra) {
+  int32_t systemScore = balanceCalcCpuScore(pDnode) + balanceCalcMemoryScore(pDnode) + balanceCalcDiskScore(pDnode) +
+                        balanceCalcBandwidthScore(pDnode);
+  float moduleScore = balanceCalcModuleScore(pDnode);
+  float vnodeScore = balanceCalcVnodeScore(pDnode, extra);
+
+  float score = systemScore + moduleScore + vnodeScore +  pDnode->customScore;
+  return score;
+}
+
+static void balanceInitDnodeList() {
+  tsBalanceDnodeList = calloc(tsBalanceDnodeListMallocSize, sizeof(SDnodeObj *));
+}
+
+static void balanceCleanupDnodeList() {
+  if (tsBalanceDnodeList != NULL) {
+    free(tsBalanceDnodeList);
+    tsBalanceDnodeList = NULL;
+  }
+}
+
+static void balanceCheckDnodeListSize(int32_t dnodesNum) {
+  if (tsBalanceDnodeListMallocSize <= dnodesNum) {
+    tsBalanceDnodeListMallocSize = dnodesNum * 2;
+    tsBalanceDnodeList = realloc(tsBalanceDnodeList, tsBalanceDnodeListMallocSize * sizeof(SDnodeObj *));
+  }
+}
+
+void balanceAccquireDnodeList() {
+  int32_t dnodesNum = mnodeGetDnodesNum();
+  balanceCheckDnodeListSize(dnodesNum);
+
+  void *     pIter = NULL;
+  SDnodeObj *pDnode = NULL;
+  int32_t    dnodeIndex = 0;
+
+  while (1) {  
+    if (dnodeIndex >= dnodesNum) break;
+    pIter = mnodeGetNextDnode(pIter, &pDnode);
+    if (pDnode == NULL) break;
+    if (pDnode->status == TAOS_DN_STATUS_OFFLINE) {
+      mnodeDecDnodeRef(pDnode);
+      continue;
+    }
+
+    balanceCalcDnodeScore(pDnode);
+    
+    int32_t orderIndex = dnodeIndex;
+    for (; orderIndex > 0; --orderIndex) {
+      if (pDnode->score > tsBalanceDnodeList[orderIndex - 1]->score) {
+        break;
+      }
+      tsBalanceDnodeList[orderIndex] = tsBalanceDnodeList[orderIndex - 1];
+    }
+    tsBalanceDnodeList[orderIndex] = pDnode;
+    dnodeIndex++;
+  }
+
+  sdbFreeIter(pIter);
+
+  tsBalanceDnodeListSize = dnodeIndex;
+}
+
+void balanceReleaseDnodeList() {
+  for (int32_t i = 0; i < tsBalanceDnodeListSize; ++i) {
+    SDnodeObj *pDnode = tsBalanceDnodeList[i];
+    if (pDnode != NULL) {
+      mnodeDecDnodeRef(pDnode);
+    }
+  }
+}
+
+static int32_t balanceGetScoresMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn) {
+  SUserObj *pUser = mnodeGetUserFromConn(pConn);
+  if (pUser == NULL) return 0;
+
+  if (strcmp(pUser->pAcct->user, "root") != 0)  {
+    mnodeDecUserRef(pUser);
+    return TSDB_CODE_MND_NO_RIGHTS;
+  }
+
+  int32_t cols = 0;
+  SSchema *pSchema = pMeta->schema;
+
+  pShow->bytes[cols] = 2;
+  pSchema[cols].type = TSDB_DATA_TYPE_SMALLINT;
+  strcpy(pSchema[cols].name, "id");
+  pSchema[cols].bytes = htons(pShow->bytes[cols]);
+  cols++;
+
+  pShow->bytes[cols] = 4;
+  pSchema[cols].type = TSDB_DATA_TYPE_FLOAT;
+  strcpy(pSchema[cols].name, "system scores");
+  pSchema[cols].bytes = htons(pShow->bytes[cols]);
+  cols++;
+
+  pShow->bytes[cols] = 4;
+  pSchema[cols].type = TSDB_DATA_TYPE_FLOAT;
+  strcpy(pSchema[cols].name, "custom scores");
+  pSchema[cols].bytes = htons(pShow->bytes[cols]);
+  cols++;
+
+  pShow->bytes[cols] = 4;
+  pSchema[cols].type = TSDB_DATA_TYPE_FLOAT;
+  strcpy(pSchema[cols].name, "module scores");
+  pSchema[cols].bytes = htons(pShow->bytes[cols]);
+  cols++;
+
+  pShow->bytes[cols] = 4;
+  pSchema[cols].type = TSDB_DATA_TYPE_FLOAT;
+  strcpy(pSchema[cols].name, "vnode scores");
+  pSchema[cols].bytes = htons(pShow->bytes[cols]);
+  cols++;
+
+  pShow->bytes[cols] = 4;
+  pSchema[cols].type = TSDB_DATA_TYPE_FLOAT;
+  strcpy(pSchema[cols].name, "total scores");
+  pSchema[cols].bytes = htons(pShow->bytes[cols]);
+  cols++;
+
+  pShow->bytes[cols] = 4;
+  pSchema[cols].type = TSDB_DATA_TYPE_INT;
+  strcpy(pSchema[cols].name, "open vnodes");
+  pSchema[cols].bytes = htons(pShow->bytes[cols]);
+  cols++;
+
+  pShow->bytes[cols] = 4;
+  pSchema[cols].type = TSDB_DATA_TYPE_INT;
+  strcpy(pSchema[cols].name, "cpu cores");
+  pSchema[cols].bytes = htons(pShow->bytes[cols]);
+  cols++;
+
+  pShow->bytes[cols] = 18 + VARSTR_HEADER_SIZE;
+  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
+  strcpy(pSchema[cols].name, "balance state");
+  pSchema[cols].bytes = htons(pShow->bytes[cols]);
+  cols++;
+
+  pMeta->numOfColumns = htons(cols);
+  pShow->numOfColumns = cols;
+
+  pShow->offset[0] = 0;
+  for (int32_t i = 1; i < cols; ++i) {
+    pShow->offset[i] = pShow->offset[i - 1] + pShow->bytes[i - 1];
+  }
+
+  pShow->numOfRows = mnodeGetDnodesNum();
+  pShow->rowSize = pShow->offset[cols - 1] + pShow->bytes[cols - 1];
+  pShow->pIter = NULL;
+
+  mnodeDecUserRef(pUser);
+
+  return 0;
+}
+
+static int32_t balanceRetrieveScores(SShowObj *pShow, char *data, int32_t rows, void *pConn) {
+  int32_t    numOfRows = 0;
+  SDnodeObj *pDnode = NULL;
+  char *     pWrite;
+  int32_t    cols = 0;
+  
+  while (numOfRows < rows) {
+    pShow->pIter = mnodeGetNextDnode(pShow->pIter, &pDnode);
+    if (pDnode == NULL) break;
+
+    int32_t systemScore = balanceCalcCpuScore(pDnode) + balanceCalcMemoryScore(pDnode) + balanceCalcDiskScore(pDnode) +
+                      balanceCalcBandwidthScore(pDnode);
+    float moduleScore = balanceCalcModuleScore(pDnode);
+    float vnodeScore = balanceCalcVnodeScore(pDnode, 0);
+
+    cols = 0;
+
+    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
+    *(int16_t *)pWrite = pDnode->dnodeId;
+    cols++;
+
+    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
+    *(float *)pWrite = systemScore;
+    cols++;
+
+    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
+    *(float *)pWrite = pDnode->customScore;
+    cols++;
+
+    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
+    *(float *)pWrite = (int32_t)moduleScore;
+    cols++;
+
+    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
+    *(float *)pWrite = (int32_t)vnodeScore;
+    cols++;
+
+    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
+    *(float *)pWrite = (int32_t)(vnodeScore + moduleScore + pDnode->customScore + systemScore);
+    cols++;
+
+    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
+    *(int32_t *)pWrite = pDnode->openVnodes;
+    cols++;
+
+    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
+    *(int32_t *)pWrite = pDnode->numOfCores;
+    cols++;
+
+    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
+    STR_TO_VARSTR(pWrite, mnodeGetDnodeStatusStr(pDnode->status));
+    cols++;
+
+    numOfRows++;
+    mnodeDecDnodeRef(pDnode);
+  }
+
+  pShow->numOfReads += numOfRows;
+  return numOfRows;
+}
+
+static void balanceMonitorDnodeModule() {
+  int32_t numOfMnodes = mnodeGetMnodesNum();
+  if (numOfMnodes >= tsNumOfMnodes) return;
+
+  for (int32_t i = 0; i < tsBalanceDnodeListSize; ++i) {
+    SDnodeObj *pDnode = tsBalanceDnodeList[i];
+    if (pDnode == NULL) break;
+
+    if (pDnode->isMgmt || pDnode->status == TAOS_DN_STATUS_DROPPING || pDnode->status == TAOS_DN_STATUS_OFFLINE) {
+      continue;
+    }
+
+    if (pDnode->alternativeRole == TAOS_DN_ALTERNATIVE_ROLE_VNODE) {
+      continue;
+    }
+
+    mLInfo("dnode:%d, numOfMnodes:%d expect:%d, add mnode in this dnode", pDnode->dnodeId, numOfMnodes, tsNumOfMnodes);
+    mnodeAddMnode(pDnode->dnodeId);
+    
+    numOfMnodes = mnodeGetMnodesNum();
+    if (numOfMnodes >= tsNumOfMnodes) return;
+  }
+}
+
+int32_t balanceAlterDnode(struct SDnodeObj *pSrcDnode, int32_t vnodeId, int32_t dnodeId) {
+  if (!sdbIsMaster()) {
+    mError("dnode:%d, failed to alter vgId:%d to dnode:%d, for self not master", pSrcDnode->dnodeId, vnodeId, dnodeId);
+    return TSDB_CODE_MND_DNODE_NOT_EXIST;
+  }
+
+  if (tsEnableBalance != 0) {
+    mError("dnode:%d, failed to alter vgId:%d to dnode:%d, for balance enabled", pSrcDnode->dnodeId, vnodeId, dnodeId);
+    return TSDB_CODE_MND_BALANCE_ENABLED;
+  }
+
+  SVgObj *pVgroup = mnodeGetVgroup(vnodeId);
+  if (pVgroup == NULL) {
+    mError("dnode:%d, failed to alter vgId:%d to dnode:%d, for vgroup not exist", pSrcDnode->dnodeId, vnodeId, dnodeId);
+    return TSDB_CODE_MND_VGROUP_NOT_EXIST;
+  }
+
+  SDnodeObj *pDestDnode = mnodeGetDnode(dnodeId);
+  if (pDestDnode == NULL) {
+    mnodeDecVgroupRef(pVgroup);
+    mError("dnode:%d, failed to alter vgId:%d to dnode:%d, for dnode not exist", pSrcDnode->dnodeId, vnodeId, dnodeId);
+    return TSDB_CODE_MND_DNODE_NOT_EXIST;
+  }
+
+  balanceLock();
+  balanceAccquireDnodeList();
+
+  int32_t code = TSDB_CODE_SUCCESS;
+  if (!balanceCheckDnodeInVgroup(pSrcDnode, pVgroup)) {
+    mError("dnode:%d, failed to alter vgId:%d to dnode:%d, vgroup not in dnode:%d", pSrcDnode->dnodeId, vnodeId,
+           dnodeId, pSrcDnode->dnodeId);
+    code = TSDB_CODE_MND_VGROUP_NOT_IN_DNODE;
+  } else if (balanceCheckDnodeInVgroup(pDestDnode, pVgroup)) {
+    mError("dnode:%d, failed to alter vgId:%d to dnode:%d, vgroup already in dnode:%d", pSrcDnode->dnodeId, vnodeId,
+           dnodeId, dnodeId);
+    code = TSDB_CODE_MND_VGROUP_ALREADY_IN_DNODE;
+  } else if (!balanceCheckFree(pDestDnode)) {
+    mError("dnode:%d, failed to alter vgId:%d to dnode:%d, for dnode:%d not free", pSrcDnode->dnodeId, vnodeId, dnodeId,
+           dnodeId);
+    code = TSDB_CODE_MND_DNODE_NOT_FREE;
+  } else {
+    code = balanceAddVnode(pVgroup, pSrcDnode, pDestDnode);
+    mInfo("dnode:%d, alter vgId:%d to dnode:%d, result:%s", pSrcDnode->dnodeId, vnodeId, dnodeId, tstrerror(code));
+  }
+
+  balanceReleaseDnodeList();
+  balanceUnLock();
+
+  mnodeDecVgroupRef(pVgroup);
+  mnodeDecDnodeRef(pDestDnode);
+
+  return code;
+}
\ No newline at end of file
diff --git a/src/client/CMakeLists.txt b/src/client/CMakeLists.txt
index 00fa1a1479..eaebd2f19d 100644
--- a/src/client/CMakeLists.txt
+++ b/src/client/CMakeLists.txt
@@ -4,11 +4,11 @@ PROJECT(TDengine)
 INCLUDE_DIRECTORIES(inc)
 INCLUDE_DIRECTORIES(jni)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/query/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/common/inc)
 INCLUDE_DIRECTORIES(${TD_ENTERPRISE_DIR}/src/inc)
-INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
 AUX_SOURCE_DIRECTORY(src SRC)
 
 IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
diff --git a/src/client/src/tscParseInsert.c b/src/client/src/tscParseInsert.c
index 95098bbab1..232ea52ded 100644
--- a/src/client/src/tscParseInsert.c
+++ b/src/client/src/tscParseInsert.c
@@ -104,7 +104,7 @@ int tsParseTime(SSQLToken *pToken, int64_t *time, char **next, char *error, int1
   } else if (strncmp(pToken->z, "0", 1) == 0 && pToken->n == 1) {
     // do nothing
   } else if (pToken->type == TK_INTEGER) {
-    useconds = str2int64(pToken->z);
+    useconds = tsosStr2int64(pToken->z);
   } else {
     // strptime("2001-11-12 18:31:01", "%Y-%m-%d %H:%M:%S", &tm);
     if (taosParseTime(pToken->z, time, pToken->n, timePrec, tsDaylight) != TSDB_CODE_SUCCESS) {
diff --git a/src/client/src/tscSystem.c b/src/client/src/tscSystem.c
index 5662b4a885..bf1b674260 100644
--- a/src/client/src/tscSystem.c
+++ b/src/client/src/tscSystem.c
@@ -220,7 +220,7 @@ static int taos_options_imp(TSDB_OPTION option, const char *pStr) {
 
         if (strlen(tsLocale) == 0) { // locale does not set yet
           char* defaultLocale = setlocale(LC_CTYPE, "");
-          tstrncpy(tsLocale, defaultLocale, sizeof(tsLocale));
+          tstrncpy(tsLocale, defaultLocale, TSDB_LOCALE_LEN);
         }
 
         // set the user specified locale
@@ -234,7 +234,7 @@ static int taos_options_imp(TSDB_OPTION option, const char *pStr) {
           tscInfo("failed to set locale:%s, current locale:%s", pStr, tsLocale);
         }
 
-        tstrncpy(tsLocale, locale, sizeof(tsLocale));
+        tstrncpy(tsLocale, locale, TSDB_LOCALE_LEN);
 
         char *charset = strrchr(tsLocale, sep);
         if (charset != NULL) {
@@ -249,7 +249,7 @@ static int taos_options_imp(TSDB_OPTION option, const char *pStr) {
               tscInfo("charset changed from %s to %s", tsCharset, charset);
             }
 
-            tstrncpy(tsCharset, charset, sizeof(tsCharset));
+            tstrncpy(tsCharset, charset, TSDB_LOCALE_LEN);
             cfg->cfgStatus = TAOS_CFG_CSTATUS_OPTION;
 
           } else {
@@ -286,7 +286,7 @@ static int taos_options_imp(TSDB_OPTION option, const char *pStr) {
             tscInfo("charset changed from %s to %s", tsCharset, pStr);
           }
 
-          tstrncpy(tsCharset, pStr, sizeof(tsCharset));
+          tstrncpy(tsCharset, pStr, TSDB_LOCALE_LEN);
           cfg->cfgStatus = TAOS_CFG_CSTATUS_OPTION;
         } else {
           tscInfo("charset:%s not valid", pStr);
@@ -304,7 +304,7 @@ static int taos_options_imp(TSDB_OPTION option, const char *pStr) {
       assert(cfg != NULL);
     
       if (cfg->cfgStatus <= TAOS_CFG_CSTATUS_OPTION) {
-        tstrncpy(tsTimezone, pStr, sizeof(tsTimezone));
+        tstrncpy(tsTimezone, pStr, TSDB_TIMEZONE_LEN);
         tsSetTimeZone();
         cfg->cfgStatus = TAOS_CFG_CSTATUS_OPTION;
         tscDebug("timezone set:%s, input:%s by taos_options", tsTimezone, pStr);
diff --git a/src/common/CMakeLists.txt b/src/common/CMakeLists.txt
index 57a32f3d69..e856481a9a 100644
--- a/src/common/CMakeLists.txt
+++ b/src/common/CMakeLists.txt
@@ -1,12 +1,11 @@
 CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
 PROJECT(TDengine)
 
-IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
-  INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
-  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
-  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
-  INCLUDE_DIRECTORIES(inc)
-  AUX_SOURCE_DIRECTORY(src SRC)
-  ADD_LIBRARY(common ${SRC})
-  TARGET_LINK_LIBRARIES(common tutil)
-ENDIF ()
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
+INCLUDE_DIRECTORIES(inc)
+
+AUX_SOURCE_DIRECTORY(src SRC)
+ADD_LIBRARY(common ${SRC})
+TARGET_LINK_LIBRARIES(common tutil)
diff --git a/src/common/inc/tglobal.h b/src/common/inc/tglobal.h
index b9afef65d9..495d2ae006 100644
--- a/src/common/inc/tglobal.h
+++ b/src/common/inc/tglobal.h
@@ -43,9 +43,9 @@ extern uint32_t tsMaxTmrCtrl;
 extern float    tsNumOfThreadsPerCore;
 extern float    tsRatioOfQueryThreads;
 extern int8_t   tsDaylight;
-extern char     tsTimezone[64];
-extern char     tsLocale[64];
-extern char     tsCharset[64];  // default encode string
+extern char     tsTimezone[];
+extern char     tsLocale[];
+extern char     tsCharset[];  // default encode string
 extern int32_t  tsEnableCoreFile;
 extern int32_t  tsCompressMsgSize;
 
diff --git a/src/common/src/tglobal.c b/src/common/src/tglobal.c
index 08349374b1..5ab2d0a36d 100644
--- a/src/common/src/tglobal.c
+++ b/src/common/src/tglobal.c
@@ -50,7 +50,7 @@ int32_t tsShellActivityTimer = 3;  // second
 float   tsNumOfThreadsPerCore = 1.0;
 float   tsRatioOfQueryThreads = 0.5;
 int8_t  tsDaylight = 0;
-char    tsTimezone[64] = {0};
+char    tsTimezone[TSDB_TIMEZONE_LEN] = {0};
 char    tsLocale[TSDB_LOCALE_LEN] = {0};
 char    tsCharset[TSDB_LOCALE_LEN] = {0};  // default encode string
 int32_t tsEnableCoreFile = 0;
diff --git a/src/cq/CMakeLists.txt b/src/cq/CMakeLists.txt
index e8796306f3..4ccdb765c3 100644
--- a/src/cq/CMakeLists.txt
+++ b/src/cq/CMakeLists.txt
@@ -1,8 +1,8 @@
 CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
 PROJECT(TDengine)
 
-INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/common/inc)
 INCLUDE_DIRECTORIES(inc)
diff --git a/src/cq/test/CMakeLists.txt b/src/cq/test/CMakeLists.txt
index 99c729dff4..82781f531a 100644
--- a/src/cq/test/CMakeLists.txt
+++ b/src/cq/test/CMakeLists.txt
@@ -1,17 +1,12 @@
 CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
 PROJECT(TDengine)
 
-IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
-  INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
-  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
-  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
-  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/common/inc)
-  INCLUDE_DIRECTORIES(../inc)
-
-  LIST(APPEND CQTEST_SRC ./cqtest.c)
-  ADD_EXECUTABLE(cqtest ${CQTEST_SRC})
-  TARGET_LINK_LIBRARIES(cqtest tcq)
-
-ENDIF ()
-
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/common/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/cq/inc)
 
+LIST(APPEND CQTEST_SRC ./cqtest.c)
+ADD_EXECUTABLE(cqtest ${CQTEST_SRC})
+TARGET_LINK_LIBRARIES(cqtest tcq)
diff --git a/src/dnode/CMakeLists.txt b/src/dnode/CMakeLists.txt
index de6e15e6b9..f7c2961352 100644
--- a/src/dnode/CMakeLists.txt
+++ b/src/dnode/CMakeLists.txt
@@ -2,8 +2,8 @@ CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
 PROJECT(TDengine)
 
 IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
-  INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/query/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/mnode/inc)
@@ -16,7 +16,7 @@ IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
   AUX_SOURCE_DIRECTORY(src SRC)
 
   ADD_EXECUTABLE(taosd ${SRC})
-  TARGET_LINK_LIBRARIES(taosd mnode taos_static monitor http mqtt tsdb twal vnode cJson lz4)
+  TARGET_LINK_LIBRARIES(taosd mnode taos_static monitor http mqtt tsdb twal vnode cJson lz4 balance sync)
 
   IF (TD_ACCOUNT)
     TARGET_LINK_LIBRARIES(taosd account)
@@ -26,10 +26,6 @@ IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
     TARGET_LINK_LIBRARIES(taosd grant)
   ENDIF ()
 
-  IF (TD_SYNC)
-    TARGET_LINK_LIBRARIES(taosd balance sync)
-  ENDIF ()
-
   SET(PREPARE_ENV_CMD "prepare_env_cmd")
   SET(PREPARE_ENV_TARGET "prepare_env_target")
   ADD_CUSTOM_COMMAND(OUTPUT ${PREPARE_ENV_CMD}
diff --git a/src/dnode/src/dnodeSystem.c b/src/dnode/src/dnodeSystem.c
index 901e0061e9..2519684878 100644
--- a/src/dnode/src/dnodeSystem.c
+++ b/src/dnode/src/dnodeSystem.c
@@ -20,7 +20,6 @@
 #include "tglobal.h"
 #include "dnodeInt.h"
 #include "dnodeMain.h"
-#include "tfile.h"
 
 static void signal_handler(int32_t signum, siginfo_t *sigInfo, void *context);
 static sem_t exitSem;
@@ -40,7 +39,7 @@ int32_t main(int32_t argc, char *argv[]) {
         exit(EXIT_FAILURE);
       }
     } else if (strcmp(argv[i], "-V") == 0) {
-#ifdef _SYNC
+#ifdef _ACCT
       char *versionStr = "enterprise";
 #else
       char *versionStr = "community";
diff --git a/src/inc/taosdef.h b/src/inc/taosdef.h
index 1bb185e448..ee95548c2d 100644
--- a/src/inc/taosdef.h
+++ b/src/inc/taosdef.h
@@ -250,7 +250,7 @@ void tsDataSwap(void *pLeft, void *pRight, int32_t type, int32_t size);
 #define TSDB_STATE_LEN            20
 #define TSDB_COUNTRY_LEN          20
 #define TSDB_LOCALE_LEN           64
-#define TSDB_TIMEZONE_LEN         64
+#define TSDB_TIMEZONE_LEN         96
 #define TSDB_LABEL_LEN            8 
 
 #define TSDB_FQDN_LEN             128
diff --git a/src/kit/shell/CMakeLists.txt b/src/kit/shell/CMakeLists.txt
index 9854a44c3b..01c5f5ea3a 100644
--- a/src/kit/shell/CMakeLists.txt
+++ b/src/kit/shell/CMakeLists.txt
@@ -2,11 +2,11 @@ CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
 PROJECT(TDengine)
 
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/client/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/query/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/common/inc)
-INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
 INCLUDE_DIRECTORIES(inc)
 
 IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
diff --git a/src/kit/taosdemo/CMakeLists.txt b/src/kit/taosdemo/CMakeLists.txt
index 627092a85b..a1593ce5a1 100644
--- a/src/kit/taosdemo/CMakeLists.txt
+++ b/src/kit/taosdemo/CMakeLists.txt
@@ -2,9 +2,9 @@ CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
 PROJECT(TDengine)
 
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/client/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
-INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
 INCLUDE_DIRECTORIES(inc)
 
 IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
diff --git a/src/kit/taosdump/CMakeLists.txt b/src/kit/taosdump/CMakeLists.txt
index c63168237c..2a14dbfb4a 100644
--- a/src/kit/taosdump/CMakeLists.txt
+++ b/src/kit/taosdump/CMakeLists.txt
@@ -2,11 +2,11 @@ CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
 PROJECT(TDengine)
 
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/common/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/client/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/query/inc)
-INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
 INCLUDE_DIRECTORIES(inc)
 
 IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
diff --git a/src/kit/taosdump/taosdump.c b/src/kit/taosdump/taosdump.c
index a1b1998298..7ae209bbdf 100644
--- a/src/kit/taosdump/taosdump.c
+++ b/src/kit/taosdump/taosdump.c
@@ -545,7 +545,7 @@ int32_t taosSaveAllNormalTableToTempFile(TAOS *taosCon, char*meter, char* metric
   strcpy(tableRecord.name, meter);
   strcpy(tableRecord.metric, metric);
 
-  twrite(*fd, &tableRecord, sizeof(STableRecord));
+  taosTWrite(*fd, &tableRecord, sizeof(STableRecord));
   return 0;
 }
 
@@ -600,7 +600,7 @@ int32_t taosSaveTableOfMetricToTempFile(TAOS *taosCon, char* metric, struct argu
     strncpy(tableRecord.name, (char *)row[0], fields[0].bytes);
     strcpy(tableRecord.metric, metric);
 
-    twrite(fd, &tableRecord, sizeof(STableRecord));
+    taosTWrite(fd, &tableRecord, sizeof(STableRecord));
 
     numOfTable++;
 
@@ -1196,7 +1196,7 @@ int32_t taosDumpCreateSuperTableClause(TAOS* taosCon, char* dbName, FILE *fp)
   while ((row = taos_fetch_row(tmpResult)) != NULL) {  
     memset(&tableRecord, 0, sizeof(STableRecord));
     strncpy(tableRecord.name, (char *)row[TSDB_SHOW_TABLES_NAME_INDEX], fields[TSDB_SHOW_TABLES_NAME_INDEX].bytes);
-    twrite(fd, &tableRecord, sizeof(STableRecord));
+    taosTWrite(fd, &tableRecord, sizeof(STableRecord));
   }  
   
   taos_free_result(tmpResult);
@@ -1282,7 +1282,7 @@ int taosDumpDb(SDbInfo *dbInfo, struct arguments *arguments, FILE *fp, TAOS *tao
     strncpy(tableRecord.name, (char *)row[TSDB_SHOW_TABLES_NAME_INDEX], fields[TSDB_SHOW_TABLES_NAME_INDEX].bytes);
     strncpy(tableRecord.metric, (char *)row[TSDB_SHOW_TABLES_METRIC_INDEX], fields[TSDB_SHOW_TABLES_METRIC_INDEX].bytes);
 
-    twrite(fd, &tableRecord, sizeof(STableRecord));
+    taosTWrite(fd, &tableRecord, sizeof(STableRecord));
 
     numOfTable++;
 
diff --git a/src/kit/taosmigrate/CMakeLists.txt b/src/kit/taosmigrate/CMakeLists.txt
index 85b2f33f01..86b428c61b 100644
--- a/src/kit/taosmigrate/CMakeLists.txt
+++ b/src/kit/taosmigrate/CMakeLists.txt
@@ -2,8 +2,8 @@ CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
 PROJECT(TDengine)
 
 IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
-  INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/mnode/inc) 
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/vnode/inc)
diff --git a/src/mnode/CMakeLists.txt b/src/mnode/CMakeLists.txt
index 2e975f089c..f5b9fbf747 100644
--- a/src/mnode/CMakeLists.txt
+++ b/src/mnode/CMakeLists.txt
@@ -2,8 +2,8 @@ CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
 PROJECT(TDengine)
 
 IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
-  INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/common/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/query/inc)
diff --git a/src/mnode/src/mnodeBalance.c b/src/mnode/src/mnodeBalance.c
deleted file mode 100644
index 95a97bd055..0000000000
--- a/src/mnode/src/mnodeBalance.c
+++ /dev/null
@@ -1,70 +0,0 @@
-/*
- * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
- *
- * This program is free software: you can use, redistribute, and/or modify
- * it under the terms of the GNU Affero General Public License, version 3
- * or later ("AGPL"), as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-#define _DEFAULT_SOURCE
-#include "os.h"
-#include "tglobal.h"
-#include "mnodeDef.h"
-#include "mnodeInt.h"
-#include "mnodeDnode.h"
-#include "mnodeSdb.h"
-
-#ifndef _SYNC
-
-int32_t balanceInit() { return TSDB_CODE_SUCCESS; }
-void    balanceCleanUp() {}
-void    balanceAsyncNotify() {}
-void    balanceSyncNotify() {}
-void    balanceReset() {}
-int32_t balanceAlterDnode(struct SDnodeObj *pDnode, int32_t vnodeId, int32_t dnodeId) { return TSDB_CODE_SYN_NOT_ENABLED; }
-
-int32_t balanceAllocVnodes(SVgObj *pVgroup) {
-  void *     pIter = NULL;
-  SDnodeObj *pDnode = NULL;
-  SDnodeObj *pSelDnode = NULL;
-  float      vnodeUsage = 1000.0;
-
-  while (1) {
-    pIter = mnodeGetNextDnode(pIter, &pDnode);
-    if (pDnode == NULL) break;
-
-    if (pDnode->numOfCores > 0 && pDnode->openVnodes < TSDB_MAX_VNODES) {
-      float openVnodes = pDnode->openVnodes;
-      if (pDnode->isMgmt) openVnodes += tsMnodeEqualVnodeNum;
-
-      float usage = openVnodes / pDnode->numOfCores;
-      if (usage <= vnodeUsage) {
-        pSelDnode = pDnode;
-        vnodeUsage = usage;
-      }
-    }
-    mnodeDecDnodeRef(pDnode);
-  }
-
-  sdbFreeIter(pIter);
-
-  if (pSelDnode == NULL) {
-    mError("failed to alloc vnode to vgroup");
-    return TSDB_CODE_MND_NO_ENOUGH_DNODES;
-  }
-
-  pVgroup->vnodeGid[0].dnodeId = pSelDnode->dnodeId;
-  pVgroup->vnodeGid[0].pDnode = pSelDnode;
-
-  mDebug("dnode:%d, alloc one vnode to vgroup, openVnodes:%d", pSelDnode->dnodeId, pSelDnode->openVnodes);
-  return TSDB_CODE_SUCCESS;
-}
-
-#endif 
diff --git a/src/mnode/src/mnodeDb.c b/src/mnode/src/mnodeDb.c
index a159e98ed5..199cc63da6 100644
--- a/src/mnode/src/mnodeDb.c
+++ b/src/mnode/src/mnodeDb.c
@@ -301,13 +301,6 @@ static int32_t mnodeCheckDbCfg(SDbCfg *pCfg) {
     return TSDB_CODE_MND_INVALID_DB_OPTION;
   }
 
-#ifndef _SYNC
-  if (pCfg->replications != 1) {
-    mError("invalid db option replications:%d can only be 1 in this version", pCfg->replications);
-    return TSDB_CODE_MND_INVALID_DB_OPTION;
-  }
-#endif
-
   return TSDB_CODE_SUCCESS;
 }
 
diff --git a/src/mnode/src/mnodeDnode.c b/src/mnode/src/mnodeDnode.c
index 4f9421efde..aa05eade24 100644
--- a/src/mnode/src/mnodeDnode.c
+++ b/src/mnode/src/mnodeDnode.c
@@ -79,9 +79,6 @@ static int32_t mnodeDnodeActionInsert(SSdbOper *pOper) {
 static int32_t mnodeDnodeActionDelete(SSdbOper *pOper) {
   SDnodeObj *pDnode = pOper->pObj;
  
-#ifndef _SYNC 
-  mnodeDropAllDnodeVgroups(pDnode);
-#endif  
   mnodeDropMnodeLocal(pDnode->dnodeId);
   balanceAsyncNotify();
 
@@ -552,12 +549,7 @@ static int32_t mnodeDropDnodeByEp(char *ep, SMnodeMsg *pMsg) {
 
   mInfo("dnode:%d, start to drop it", pDnode->dnodeId);
 
-#ifndef _SYNC
-  int32_t code = mnodeDropDnode(pDnode, pMsg);
-#else
   int32_t code = balanceDropDnode(pDnode);
-#endif
-
   mnodeDecDnodeRef(pDnode);
   return code;
 }
diff --git a/src/os/CMakeLists.txt b/src/os/CMakeLists.txt
index f88209ad9b..a8664669d0 100644
--- a/src/os/CMakeLists.txt
+++ b/src/os/CMakeLists.txt
@@ -1,6 +1,16 @@
 CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
 PROJECT(TDengine)
 
-ADD_SUBDIRECTORY(linux)
-ADD_SUBDIRECTORY(windows)
-ADD_SUBDIRECTORY(darwin)
+IF (TD_LINUX_64)
+  ADD_SUBDIRECTORY(src/linux64)
+ELSEIF (TD_LINUX_32)
+  ADD_SUBDIRECTORY(src/linux32)
+ELSEIF (TD_DARWIN_64)
+  ADD_SUBDIRECTORY(src/darwin64)  
+ELSEIF (TD_WINDOWS_64)
+  ADD_SUBDIRECTORY(src/windows64)
+ELSEIF (TD_WINDOWS_32)
+  ADD_SUBDIRECTORY(src/windows32)
+ENDIF ()
+
+ADD_SUBDIRECTORY(src/detail)
diff --git a/src/os/darwin/CMakeLists.txt b/src/os/darwin/CMakeLists.txt
deleted file mode 100644
index 116d0ec8c0..0000000000
--- a/src/os/darwin/CMakeLists.txt
+++ /dev/null
@@ -1,9 +0,0 @@
-CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
-PROJECT(TDengine)
-
-IF (TD_DARWIN_64)
-  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
-  INCLUDE_DIRECTORIES(inc)
-  AUX_SOURCE_DIRECTORY(src SRC)
-  ADD_LIBRARY(os ${SRC})
-ENDIF ()
diff --git a/src/os/inc/os.h b/src/os/inc/os.h
new file mode 100644
index 0000000000..896f3afc7a
--- /dev/null
+++ b/src/os/inc/os.h
@@ -0,0 +1,53 @@
+/*
+ * 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 TDENGINE_OS_H
+#define TDENGINE_OS_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifdef _TD_DARWIN_64
+#include "osDarwin64.h"
+#endif
+
+#ifdef _TD_LINUX_64
+#include "osLinux64.h"
+#endif
+
+#ifdef _TD_LINUX_32
+#include "osLinux32.h"
+#endif
+
+#ifdef _TD_ALPINE
+#include "osAlpine.h"
+#endif
+
+#ifdef _TD_WINDOWS_64
+#include "osWindows64.h"
+#endif
+
+#ifdef _TD_WINDOWS_32
+#include "osWindows32.h"
+#endif
+
+#include "osSpec.h"
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/src/os/inc/osAlpine.h b/src/os/inc/osAlpine.h
new file mode 100644
index 0000000000..b8212373ce
--- /dev/null
+++ b/src/os/inc/osAlpine.h
@@ -0,0 +1,91 @@
+/*
+ * 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 TDENGINE_OS_LINUX64_H
+#define TDENGINE_OS_LINUX64_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <argp.h>
+#include <arpa/inet.h>
+#include <assert.h>
+#include <ctype.h>
+#include <dirent.h>
+#include <endian.h>
+#include <errno.h>
+#include <float.h>
+#include <ifaddrs.h>
+#include <libgen.h>
+#include <limits.h>
+#include <locale.h>
+#include <math.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <netinet/ip.h>
+#include <netinet/tcp.h>
+#include <netinet/udp.h>
+#include <pthread.h>
+#include <pwd.h>
+#include <regex.h>
+#include <semaphore.h>
+#include <signal.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+#include <strings.h>
+#include <sys/epoll.h>
+#include <sys/eventfd.h>
+#include <sys/file.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/sendfile.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <sys/statvfs.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <sys/un.h>
+#include <syslog.h>
+#include <termios.h>
+#include <unistd.h>
+#include <wchar.h>
+#include <wordexp.h>
+#include <wctype.h>
+#include <inttypes.h>
+#include <fcntl.h>
+#include <sys/utsname.h>
+#include <sys/resource.h>
+#include <linux/sysctl.h>
+
+typedef int(*__compar_fn_t)(const void *, const void *);
+void  error (int, int, const char *);
+#ifndef PTHREAD_MUTEX_RECURSIVE_NP
+  #define  PTHREAD_MUTEX_RECURSIVE_NP PTHREAD_MUTEX_RECURSIVE
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/src/os/darwin/inc/os.h b/src/os/inc/osDarwin64.h
similarity index 96%
rename from src/os/darwin/inc/os.h
rename to src/os/inc/osDarwin64.h
index 1c719933a4..2bb0777ab8 100644
--- a/src/os/darwin/inc/os.h
+++ b/src/os/inc/osDarwin64.h
@@ -201,6 +201,8 @@ int tsem_destroy(dispatch_semaphore_t *sem);
 
 void osInit();
 
+ssize_t tread(int fd, void *buf, size_t count);
+
 ssize_t twrite(int fd, void *buf, size_t n);
 
 char *taosCharsetReplace(char *charsetstr);
@@ -233,6 +235,8 @@ int fsendfile(FILE* out_file, FILE* in_file, int64_t* offset, int32_t count);
 
 void taosSetCoreDump();
 
+int tSystem(const char * cmd);
+
 typedef int(*__compar_fn_t)(const void *, const void *);
 
 // for send function in tsocket.c
@@ -255,6 +259,17 @@ typedef int(*__compar_fn_t)(const void *, const void *);
 #define BUILDIN_CLZ(val)  __builtin_clz(val)
 #define BUILDIN_CTZ(val)  __builtin_ctz(val)
 
+#undef threadlocal
+#ifdef _ISOC11_SOURCE
+  #define threadlocal _Thread_local
+#elif defined(__APPLE__)
+  #define threadlocal
+#elif defined(__GNUC__) && !defined(threadlocal)
+  #define threadlocal __thread
+#else
+  #define threadlocal
+#endif
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/os/inc/osLinux32.h b/src/os/inc/osLinux32.h
new file mode 100644
index 0000000000..1778b0e315
--- /dev/null
+++ b/src/os/inc/osLinux32.h
@@ -0,0 +1,85 @@
+/*
+ * 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 TDENGINE_OS_LINUX64_H
+#define TDENGINE_OS_LINUX64_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <argp.h>
+#include <arpa/inet.h>
+#include <assert.h>
+#include <ctype.h>
+#include <dirent.h>
+#include <endian.h>
+#include <errno.h>
+#include <float.h>
+#include <ifaddrs.h>
+#include <libgen.h>
+#include <limits.h>
+#include <locale.h>
+#include <math.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <netinet/ip.h>
+#include <netinet/tcp.h>
+#include <netinet/udp.h>
+#include <pthread.h>
+#include <pwd.h>
+#include <regex.h>
+#include <semaphore.h>
+#include <signal.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+#include <strings.h>
+#include <sys/epoll.h>
+#include <sys/eventfd.h>
+#include <sys/file.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/sendfile.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <sys/statvfs.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <sys/un.h>
+#include <syslog.h>
+#include <termios.h>
+#include <unistd.h>
+#include <wchar.h>
+#include <wordexp.h>
+#include <wctype.h>
+#include <inttypes.h>
+#include <fcntl.h>
+#include <sys/utsname.h>
+#include <sys/resource.h>
+#include <error.h>
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/src/os/inc/osLinux64.h b/src/os/inc/osLinux64.h
new file mode 100644
index 0000000000..0a99f4b745
--- /dev/null
+++ b/src/os/inc/osLinux64.h
@@ -0,0 +1,85 @@
+/*
+ * 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 TDENGINE_OS_LINUX64_H
+#define TDENGINE_OS_LINUX64_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <argp.h>
+#include <arpa/inet.h>
+#include <assert.h>
+#include <ctype.h>
+#include <dirent.h>
+#include <endian.h>
+#include <errno.h>
+#include <float.h>
+#include <ifaddrs.h>
+#include <libgen.h>
+#include <limits.h>
+#include <locale.h>
+#include <math.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <netinet/ip.h>
+#include <netinet/tcp.h>
+#include <netinet/udp.h>
+#include <pthread.h>
+#include <pwd.h>
+#include <regex.h>
+#include <semaphore.h>
+#include <signal.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+#include <strings.h>
+#include <sys/epoll.h>
+#include <sys/eventfd.h>
+#include <sys/file.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/sendfile.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <sys/statvfs.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <sys/un.h>
+#include <syslog.h>
+#include <termios.h>
+#include <unistd.h>
+#include <wchar.h>
+#include <wordexp.h>
+#include <wctype.h>
+#include <inttypes.h>
+#include <fcntl.h>
+#include <sys/utsname.h>
+#include <sys/resource.h>
+#include <error.h>
+#include <linux/sysctl.h>
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/src/os/inc/osSpec.h b/src/os/inc/osSpec.h
new file mode 100644
index 0000000000..b7b7bd9ff4
--- /dev/null
+++ b/src/os/inc/osSpec.h
@@ -0,0 +1,240 @@
+/*
+ * 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 TDENGINE_OS_SPEC_H
+#define TDENGINE_OS_SPEC_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef TAOS_OS_FUNC_MATH
+  #define SWAP(a, b, c)        \
+    do {                       \
+        typeof(a) __tmp = (a); \
+        (a) = (b);             \
+        (b) = __tmp;           \
+    } while (0)
+
+  #define MAX(a, b)              \
+    ({                           \
+        typeof(a) __a = (a);     \
+        typeof(b) __b = (b);     \
+        (__a > __b) ? __a : __b; \
+    })
+
+  #define MIN(a, b)              \
+    ({                           \
+        typeof(a) __a = (a);     \
+        typeof(b) __b = (b);     \
+        (__a < __b) ? __a : __b; \
+    })
+#endif
+
+#ifndef TAOS_OS_DEF_TIME
+  #define MILLISECOND_PER_SECOND ((int64_t)1000L)
+#endif
+
+#ifndef TAOS_OS_FUNC_SEMPHONE
+  #define tsem_t sem_t
+  #define tsem_init sem_init
+  #define tsem_wait sem_wait
+  #define tsem_post sem_post
+  #define tsem_destroy sem_destroy
+#endif
+
+#ifndef TAOS_OS_FUNC_ATOMIC
+  #define atomic_load_8(ptr) __atomic_load_n((ptr), __ATOMIC_SEQ_CST)
+  #define atomic_load_16(ptr) __atomic_load_n((ptr), __ATOMIC_SEQ_CST)
+  #define atomic_load_32(ptr) __atomic_load_n((ptr), __ATOMIC_SEQ_CST)
+  #define atomic_load_64(ptr) __atomic_load_n((ptr), __ATOMIC_SEQ_CST)
+  #define atomic_load_ptr(ptr) __atomic_load_n((ptr), __ATOMIC_SEQ_CST)
+
+  #define atomic_store_8(ptr, val) __atomic_store_n((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_store_16(ptr, val) __atomic_store_n((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_store_32(ptr, val) __atomic_store_n((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_store_64(ptr, val) __atomic_store_n((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_store_ptr(ptr, val) __atomic_store_n((ptr), (val), __ATOMIC_SEQ_CST)
+
+  #define atomic_exchange_8(ptr, val) __atomic_exchange_n((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_exchange_16(ptr, val) __atomic_exchange_n((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_exchange_32(ptr, val) __atomic_exchange_n((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_exchange_64(ptr, val) __atomic_exchange_n((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_exchange_ptr(ptr, val) __atomic_exchange_n((ptr), (val), __ATOMIC_SEQ_CST)
+
+  #define atomic_val_compare_exchange_8 __sync_val_compare_and_swap
+  #define atomic_val_compare_exchange_16 __sync_val_compare_and_swap
+  #define atomic_val_compare_exchange_32 __sync_val_compare_and_swap
+  #define atomic_val_compare_exchange_64 __sync_val_compare_and_swap
+  #define atomic_val_compare_exchange_ptr __sync_val_compare_and_swap
+
+  #define atomic_add_fetch_8(ptr, val) __atomic_add_fetch((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_add_fetch_16(ptr, val) __atomic_add_fetch((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_add_fetch_32(ptr, val) __atomic_add_fetch((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_add_fetch_64(ptr, val) __atomic_add_fetch((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_add_fetch_ptr(ptr, val) __atomic_add_fetch((ptr), (val), __ATOMIC_SEQ_CST)
+
+  #define atomic_fetch_add_8(ptr, val) __atomic_fetch_add((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_fetch_add_16(ptr, val) __atomic_fetch_add((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_fetch_add_32(ptr, val) __atomic_fetch_add((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_fetch_add_64(ptr, val) __atomic_fetch_add((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_fetch_add_ptr(ptr, val) __atomic_fetch_add((ptr), (val), __ATOMIC_SEQ_CST)
+
+  #define atomic_sub_fetch_8(ptr, val) __atomic_sub_fetch((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_sub_fetch_16(ptr, val) __atomic_sub_fetch((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_sub_fetch_32(ptr, val) __atomic_sub_fetch((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_sub_fetch_64(ptr, val) __atomic_sub_fetch((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_sub_fetch_ptr(ptr, val) __atomic_sub_fetch((ptr), (val), __ATOMIC_SEQ_CST)
+
+  #define atomic_fetch_sub_8(ptr, val) __atomic_fetch_sub((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_fetch_sub_16(ptr, val) __atomic_fetch_sub((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_fetch_sub_32(ptr, val) __atomic_fetch_sub((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_fetch_sub_64(ptr, val) __atomic_fetch_sub((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_fetch_sub_ptr(ptr, val) __atomic_fetch_sub((ptr), (val), __ATOMIC_SEQ_CST)
+
+  #define atomic_and_fetch_8(ptr, val) __atomic_and_fetch((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_and_fetch_16(ptr, val) __atomic_and_fetch((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_and_fetch_32(ptr, val) __atomic_and_fetch((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_and_fetch_64(ptr, val) __atomic_and_fetch((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_and_fetch_ptr(ptr, val) __atomic_and_fetch((ptr), (val), __ATOMIC_SEQ_CST)
+
+  #define atomic_fetch_and_8(ptr, val) __atomic_fetch_and((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_fetch_and_16(ptr, val) __atomic_fetch_and((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_fetch_and_32(ptr, val) __atomic_fetch_and((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_fetch_and_64(ptr, val) __atomic_fetch_and((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_fetch_and_ptr(ptr, val) __atomic_fetch_and((ptr), (val), __ATOMIC_SEQ_CST)
+
+  #define atomic_or_fetch_8(ptr, val) __atomic_or_fetch((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_or_fetch_16(ptr, val) __atomic_or_fetch((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_or_fetch_32(ptr, val) __atomic_or_fetch((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_or_fetch_64(ptr, val) __atomic_or_fetch((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_or_fetch_ptr(ptr, val) __atomic_or_fetch((ptr), (val), __ATOMIC_SEQ_CST)
+
+  #define atomic_fetch_or_8(ptr, val) __atomic_fetch_or((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_fetch_or_16(ptr, val) __atomic_fetch_or((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_fetch_or_32(ptr, val) __atomic_fetch_or((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_fetch_or_64(ptr, val) __atomic_fetch_or((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_fetch_or_ptr(ptr, val) __atomic_fetch_or((ptr), (val), __ATOMIC_SEQ_CST)
+
+  #define atomic_xor_fetch_8(ptr, val) __atomic_xor_fetch((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_xor_fetch_16(ptr, val) __atomic_xor_fetch((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_xor_fetch_32(ptr, val) __atomic_xor_fetch((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_xor_fetch_64(ptr, val) __atomic_xor_fetch((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_xor_fetch_ptr(ptr, val) __atomic_xor_fetch((ptr), (val), __ATOMIC_SEQ_CST)
+
+  #define atomic_fetch_xor_8(ptr, val) __atomic_fetch_xor((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_fetch_xor_16(ptr, val) __atomic_fetch_xor((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_fetch_xor_32(ptr, val) __atomic_fetch_xor((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_fetch_xor_64(ptr, val) __atomic_fetch_xor((ptr), (val), __ATOMIC_SEQ_CST)
+  #define atomic_fetch_xor_ptr(ptr, val) __atomic_fetch_xor((ptr), (val), __ATOMIC_SEQ_CST)
+#endif
+
+ssize_t taosTReadImp(int fd, void *buf, size_t count);
+ssize_t taosTWriteImp(int fd, void *buf, size_t count);
+ssize_t taosTSendFileImp(int dfd, int sfd, off_t *offset, size_t size);
+#ifndef TAOS_OS_FUNC_FILE
+  #define taosTRead(fd, buf, count) taosTReadImp(fd, buf, count)
+  #define taosTWrite(fd, buf, count) taosTWriteImp(fd, buf, count)
+  #define taosLSeek(fd, offset, whence) lseek(fd, offset, whence)
+  #define taosTSendFile(dfd, sfd, offset, size) taosTSendFileImp(dfd, sfd, offset, size)
+#endif
+
+#ifdef TAOS_RANDOM_FILE_FAIL
+  void taosSetRandomFileFailFactor(int factor);
+  void taosSetRandomFileFailOutput(const char *path);
+  ssize_t taosReadFileRandomFail(int fd, void *buf, size_t count, const char *file, uint32_t line);
+  ssize_t taosWriteFileRandomFail(int fd, void *buf, size_t count, const char *file, uint32_t line);
+  off_t taosLSeekRandomFail(int fd, off_t offset, int whence, const char *file, uint32_t line);
+  #define taosTRead(fd, buf, count) taosReadFileRandomFail(fd, buf, count, __FILE__, __LINE__)
+  #define taosTWrite(fd, buf, count) taosWriteFileRandomFail(fd, buf, count, __FILE__, __LINE__)
+  #define taosLSeek(fd, offset, whence) taosLSeekRandomFail(fd, offset, whence, __FILE__, __LINE__)
+#endif
+
+#ifndef TAOS_OS_FUNC_NETWORK
+  #define taosSend(sockfd, buf, len, flags) send(sockfd, buf, len, flags)
+  #define taosSendto(sockfd, buf, len, flags, dest_addr, addrlen) sendto(sockfd, buf, len, flags, dest_addr, addrlen)
+  #define taosReadSocket(fd, buf, len) read(fd, buf, len)
+  #define taosWriteSocket(fd, buf, len) write(fd, buf, len)
+  #define taosCloseSocket(x) \
+    {                        \
+      if (FD_VALID(x)) {     \
+        close(x);            \
+        x = FD_INITIALIZER;  \
+      }                      \
+    }
+#endif
+
+#ifdef TAOS_RANDOM_NETWORK_FAIL
+  ssize_t taosSendRandomFail(int sockfd, const void *buf, size_t len, int flags);
+  ssize_t taosSendToRandomFail(int sockfd, const void *buf, size_t len, int flags, const struct sockaddr *dest_addr, socklen_t addrlen);
+  ssize_t taosReadSocketRandomFail(int fd, void *buf, size_t count);
+  ssize_t taosWriteSocketRandomFail(int fd, const void *buf, size_t count);
+  #define taosSend(sockfd, buf, len, flags) taosSendRandomFail(sockfd, buf, len, flags)
+  #define taosSendto(sockfd, buf, len, flags, dest_addr, addrlen) taosSendToRandomFail(sockfd, buf, len, flags, dest_addr, addrlen)
+  #define taosReadSocket(fd, buf, len) taosReadSocketRandomFail(fd, buf, len)
+  #define taosWriteSocket(fd, buf, len) taosWriteSocketRandomFail(fd, buf, len)
+#endif
+
+#ifndef TAOS_OS_FUNC_LZ4
+  #define BUILDIN_CLZL(val) __builtin_clzl(val)
+  #define BUILDIN_CTZL(val) __builtin_ctzl(val)
+  #define BUILDIN_CLZ(val) __builtin_clz(val)
+  #define BUILDIN_CTZ(val) __builtin_ctz(val)
+#endif
+
+#undef threadlocal
+#ifdef _ISOC11_SOURCE
+  #define threadlocal _Thread_local
+#elif defined(__APPLE__)
+  #define threadlocal
+#elif defined(__GNUC__) && !defined(threadlocal)
+  #define threadlocal __thread
+#else
+  #define threadlocal
+#endif
+
+void osInit();
+
+// TAOS_OS_FUNC_PTHREAD
+bool taosCheckPthreadValid(pthread_t thread);
+int64_t taosGetPthreadId();
+
+// TAOS_OS_FUNC_SOCKET
+int taosSetNonblocking(int sock, int on);
+int taosSetSockOpt(int socketfd, int level, int optname, void *optval, int optlen);
+void taosBlockSIGPIPE();
+
+// TAOS_OS_FUNC_SYSINFO
+void taosGetSystemInfo();
+void taosPrintOsInfo();
+void taosKillSystem();
+int tSystem(const char * cmd) ;
+
+// TAOS_OS_FUNC_CORE
+void taosSetCoreDump();
+
+// TAOS_OS_FUNC_UTIL
+int64_t tsosStr2int64(char *str);
+
+// TAOS_OS_FUNC_TIMER
+void taosMsleep(int mseconds);
+int taosInitTimer(void (*callback)(int), int ms);
+void taosUninitTimer();
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/src/os/inc/osWindows32.h b/src/os/inc/osWindows32.h
new file mode 100644
index 0000000000..4744d4beb5
--- /dev/null
+++ b/src/os/inc/osWindows32.h
@@ -0,0 +1,54 @@
+/*
+* 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 TDENGINE_PLATFORM_WINDOWS32_H
+#define TDENGINE_PLATFORM_WINDOWS32_H
+
+#include <assert.h>
+#include <ctype.h>
+#include <direct.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <float.h>
+#include <locale.h>
+#include <intrin.h>
+#include <io.h>
+#include <math.h>
+#include <pthread.h>
+#include <semaphore.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <signal.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <time.h>
+#include <inttypes.h>
+#include "winsock2.h"
+#include <WS2tcpip.h>
+#include <winbase.h>
+#include <Winsock2.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+#endif
\ No newline at end of file
diff --git a/src/os/windows/inc/os.h b/src/os/inc/osWindows64.h
similarity index 99%
rename from src/os/windows/inc/os.h
rename to src/os/inc/osWindows64.h
index a1901aa6e7..8fd41fb2fd 100644
--- a/src/os/windows/inc/os.h
+++ b/src/os/inc/osWindows64.h
@@ -78,10 +78,10 @@ extern "C" {
 #define wcsncasecmp _wcsnicmp
 #define strtok_r strtok_s
 #ifdef _TD_GO_DLL_
-  int64_t str2int64(char *str);
+  int64_t tsosStr2int64(char *str);
   uint64_t htonll(uint64_t val);
 #else
-  #define str2int64 _atoi64
+  #define tsosStr2int64 _atoi64
 #endif
 
 #define snprintf _snprintf
diff --git a/src/os/linux/inc/os.h b/src/os/linux/inc/os.h
deleted file mode 100644
index 00b9f33f1b..0000000000
--- a/src/os/linux/inc/os.h
+++ /dev/null
@@ -1,294 +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/>.
- */
-
-#ifndef TDENGINE_PLATFORM_LINUX_H
-#define TDENGINE_PLATFORM_LINUX_H
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-#include <stdio.h>
-#include <stdlib.h>
-
-#include <argp.h>
-#include <arpa/inet.h>
-#include <assert.h>
-#include <ctype.h>
-#include <dirent.h>
-#include <endian.h>
-#include <errno.h>
-#include <float.h>
-#include <ifaddrs.h>
-#include <libgen.h>
-#include <limits.h>
-#include <locale.h>
-#include <math.h>
-#include <netdb.h>
-#include <netinet/in.h>
-#include <netinet/ip.h>
-#include <netinet/tcp.h>
-#include <netinet/udp.h>
-#include <pthread.h>
-#include <pwd.h>
-#include <regex.h>
-#include <semaphore.h>
-#include <signal.h>
-#include <stdarg.h>
-#include <stdbool.h>
-#include <stddef.h>
-#include <stdint.h>
-#include <string.h>
-#include <strings.h>
-#include <sys/epoll.h>
-#include <sys/eventfd.h>
-#include <sys/file.h>
-#include <sys/ioctl.h>
-#include <sys/mman.h>
-#include <sys/sendfile.h>
-#include <sys/socket.h>
-#include <sys/stat.h>
-#include <sys/syscall.h>
-#include <sys/statvfs.h>
-#include <sys/time.h>
-#include <sys/types.h>
-#include <sys/uio.h>
-#include <sys/un.h>
-#include <syslog.h>
-#include <termios.h>
-#include <unistd.h>
-#include <wchar.h>
-#include <wordexp.h>
-#include <wctype.h>
-#include <inttypes.h>
-#include <fcntl.h>
-#include <sys/utsname.h>
-#include <sys/resource.h>
-#include <error.h>
-
-#define taosCloseSocket(x) \
-  {                        \
-    if (FD_VALID(x)) {     \
-      close(x);            \
-      x = FD_INITIALIZER;  \
-    }                      \
-  }
-  
-#ifdef TAOS_RANDOM_NETWORK_FAIL
-
-ssize_t taos_send_random_fail(int sockfd, const void *buf, size_t len, int flags);
-
-ssize_t taos_sendto_random_fail(int sockfd, const void *buf, size_t len, int flags,
-                      const struct sockaddr *dest_addr, socklen_t addrlen);
-ssize_t taos_read_random_fail(int fd, void *buf, size_t count);
-ssize_t taos_write_random_fail(int fd, const void *buf, size_t count);
-
-#define send(sockfd, buf, len, flags) taos_send_random_fail(sockfd, buf, len, flags)
-#define sendto(sockfd, buf, len, flags, dest_addr, addrlen) \
-          taos_sendto_random_fail(sockfd, buf, len, flags, dest_addr, addrlen)
-#define taosWriteSocket(fd, buf, len) taos_write_random_fail(fd, buf, len)
-#define taosReadSocket(fd, buf, len) taos_read_random_fail(fd, buf, len)
-
-#else
-
-#define taosWriteSocket(fd, buf, len) write(fd, buf, len)
-#define taosReadSocket(fd, buf, len) read(fd, buf, len)
-
-#endif  /* TAOS_RANDOM_NETWORK_FAIL */
-
-#define atomic_load_8(ptr) __atomic_load_n((ptr), __ATOMIC_SEQ_CST)
-#define atomic_load_16(ptr) __atomic_load_n((ptr), __ATOMIC_SEQ_CST)
-#define atomic_load_32(ptr) __atomic_load_n((ptr), __ATOMIC_SEQ_CST)
-#define atomic_load_64(ptr) __atomic_load_n((ptr), __ATOMIC_SEQ_CST)
-#define atomic_load_ptr(ptr) __atomic_load_n((ptr), __ATOMIC_SEQ_CST)
-
-#define atomic_store_8(ptr, val) __atomic_store_n((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_store_16(ptr, val) __atomic_store_n((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_store_32(ptr, val) __atomic_store_n((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_store_64(ptr, val) __atomic_store_n((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_store_ptr(ptr, val) __atomic_store_n((ptr), (val), __ATOMIC_SEQ_CST)
-
-#define atomic_exchange_8(ptr, val) __atomic_exchange_n((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_exchange_16(ptr, val) __atomic_exchange_n((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_exchange_32(ptr, val) __atomic_exchange_n((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_exchange_64(ptr, val) __atomic_exchange_n((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_exchange_ptr(ptr, val) __atomic_exchange_n((ptr), (val), __ATOMIC_SEQ_CST)
-
-#define atomic_val_compare_exchange_8 __sync_val_compare_and_swap
-#define atomic_val_compare_exchange_16 __sync_val_compare_and_swap
-#define atomic_val_compare_exchange_32 __sync_val_compare_and_swap
-#define atomic_val_compare_exchange_64 __sync_val_compare_and_swap
-#define atomic_val_compare_exchange_ptr __sync_val_compare_and_swap
-
-#define atomic_add_fetch_8(ptr, val) __atomic_add_fetch((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_add_fetch_16(ptr, val) __atomic_add_fetch((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_add_fetch_32(ptr, val) __atomic_add_fetch((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_add_fetch_64(ptr, val) __atomic_add_fetch((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_add_fetch_ptr(ptr, val) __atomic_add_fetch((ptr), (val), __ATOMIC_SEQ_CST)
-
-#define atomic_fetch_add_8(ptr, val) __atomic_fetch_add((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_fetch_add_16(ptr, val) __atomic_fetch_add((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_fetch_add_32(ptr, val) __atomic_fetch_add((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_fetch_add_64(ptr, val) __atomic_fetch_add((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_fetch_add_ptr(ptr, val) __atomic_fetch_add((ptr), (val), __ATOMIC_SEQ_CST)
-
-#define atomic_sub_fetch_8(ptr, val) __atomic_sub_fetch((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_sub_fetch_16(ptr, val) __atomic_sub_fetch((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_sub_fetch_32(ptr, val) __atomic_sub_fetch((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_sub_fetch_64(ptr, val) __atomic_sub_fetch((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_sub_fetch_ptr(ptr, val) __atomic_sub_fetch((ptr), (val), __ATOMIC_SEQ_CST)
-
-#define atomic_fetch_sub_8(ptr, val) __atomic_fetch_sub((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_fetch_sub_16(ptr, val) __atomic_fetch_sub((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_fetch_sub_32(ptr, val) __atomic_fetch_sub((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_fetch_sub_64(ptr, val) __atomic_fetch_sub((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_fetch_sub_ptr(ptr, val) __atomic_fetch_sub((ptr), (val), __ATOMIC_SEQ_CST)
-
-#define atomic_and_fetch_8(ptr, val) __atomic_and_fetch((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_and_fetch_16(ptr, val) __atomic_and_fetch((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_and_fetch_32(ptr, val) __atomic_and_fetch((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_and_fetch_64(ptr, val) __atomic_and_fetch((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_and_fetch_ptr(ptr, val) __atomic_and_fetch((ptr), (val), __ATOMIC_SEQ_CST)
-
-#define atomic_fetch_and_8(ptr, val) __atomic_fetch_and((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_fetch_and_16(ptr, val) __atomic_fetch_and((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_fetch_and_32(ptr, val) __atomic_fetch_and((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_fetch_and_64(ptr, val) __atomic_fetch_and((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_fetch_and_ptr(ptr, val) __atomic_fetch_and((ptr), (val), __ATOMIC_SEQ_CST)
-
-#define atomic_or_fetch_8(ptr, val) __atomic_or_fetch((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_or_fetch_16(ptr, val) __atomic_or_fetch((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_or_fetch_32(ptr, val) __atomic_or_fetch((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_or_fetch_64(ptr, val) __atomic_or_fetch((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_or_fetch_ptr(ptr, val) __atomic_or_fetch((ptr), (val), __ATOMIC_SEQ_CST)
-
-#define atomic_fetch_or_8(ptr, val) __atomic_fetch_or((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_fetch_or_16(ptr, val) __atomic_fetch_or((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_fetch_or_32(ptr, val) __atomic_fetch_or((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_fetch_or_64(ptr, val) __atomic_fetch_or((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_fetch_or_ptr(ptr, val) __atomic_fetch_or((ptr), (val), __ATOMIC_SEQ_CST)
-
-#define atomic_xor_fetch_8(ptr, val) __atomic_xor_fetch((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_xor_fetch_16(ptr, val) __atomic_xor_fetch((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_xor_fetch_32(ptr, val) __atomic_xor_fetch((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_xor_fetch_64(ptr, val) __atomic_xor_fetch((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_xor_fetch_ptr(ptr, val) __atomic_xor_fetch((ptr), (val), __ATOMIC_SEQ_CST)
-
-#define atomic_fetch_xor_8(ptr, val) __atomic_fetch_xor((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_fetch_xor_16(ptr, val) __atomic_fetch_xor((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_fetch_xor_32(ptr, val) __atomic_fetch_xor((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_fetch_xor_64(ptr, val) __atomic_fetch_xor((ptr), (val), __ATOMIC_SEQ_CST)
-#define atomic_fetch_xor_ptr(ptr, val) __atomic_fetch_xor((ptr), (val), __ATOMIC_SEQ_CST)
-
-#define SWAP(a, b, c)      \
-  do {                     \
-    typeof(a) __tmp = (a); \
-    (a) = (b);             \
-    (b) = __tmp;           \
-  } while (0)
-
-#define MAX(a, b)            \
-  ({                         \
-    typeof(a) __a = (a);     \
-    typeof(b) __b = (b);     \
-    (__a > __b) ? __a : __b; \
-  })
-
-#define MIN(a, b)            \
-  ({                         \
-    typeof(a) __a = (a);     \
-    typeof(b) __b = (b);     \
-    (__a < __b) ? __a : __b; \
-  })
-
-#define MILLISECOND_PER_SECOND ((int64_t)1000L)
-
-#define tsem_t sem_t
-#define tsem_init sem_init
-#define tsem_wait sem_wait
-#define tsem_post sem_post
-#define tsem_destroy sem_destroy
-
-void osInit();
-
-ssize_t tsendfile(int dfd, int sfd, off_t *offset, size_t size);
-
-ssize_t twrite(int fd, void *buf, size_t n);
-
-ssize_t tread(int fd, void *buf, size_t count);
-
-bool taosCheckPthreadValid(pthread_t thread);
-
-void taosResetPthread(pthread_t *thread);
-
-int64_t taosGetPthreadId();
-
-int taosSetNonblocking(int sock, int on);
-
-int taosSetSockOpt(int socketfd, int level, int optname, void *optval, int optlen);
-
-void taosPrintOsInfo();
-
-char *taosCharsetReplace(char *charsetstr);
-
-void taosGetSystemInfo();
-
-void taosKillSystem();
-
-bool taosSkipSocketCheck();
-
-int64_t str2int64(char *str);
-
-void taosSetCoreDump();
-
-void taosBlockSIGPIPE();
-
-int tSystem(const char * cmd) ;
-
-
-#ifdef _ALPINE
-  typedef int(*__compar_fn_t)(const void *, const void *);
-  void  error (int, int, const char *);
-  #ifndef PTHREAD_MUTEX_RECURSIVE_NP
-    #define  PTHREAD_MUTEX_RECURSIVE_NP PTHREAD_MUTEX_RECURSIVE
-  #endif
-#endif
-
-#ifndef _TD_ARM_32_
-#define BUILDIN_CLZL(val) __builtin_clzl(val)
-#define BUILDIN_CTZL(val) __builtin_ctzl(val)
-#else
-#define BUILDIN_CLZL(val) __builtin_clzll(val)
-#define BUILDIN_CTZL(val) __builtin_ctzll(val)
-#endif
-#define BUILDIN_CLZ(val) __builtin_clz(val)
-#define BUILDIN_CTZ(val) __builtin_ctz(val)
-
-#undef threadlocal
-#ifdef _ISOC11_SOURCE
-  #define threadlocal _Thread_local
-#elif defined(__APPLE__)
-  #define threadlocal
-#elif defined(__GNUC__) && !defined(threadlocal)
-  #define threadlocal __thread
-#else
-  #define threadlocal
-#endif
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif
diff --git a/src/os/linux/src/linuxPlatform.c b/src/os/linux/src/linuxPlatform.c
deleted file mode 100644
index 216d8942bc..0000000000
--- a/src/os/linux/src/linuxPlatform.c
+++ /dev/null
@@ -1,318 +0,0 @@
-/*
- * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
- *
- * This program is free software: you can use, redistribute, and/or modify
- * it under the terms of the GNU Affero General Public License, version 3
- * or later ("AGPL"), as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-#define _DEFAULT_SOURCE
-#include "os.h"
-#include "taosdef.h"
-#include "tglobal.h"
-#include "ttimer.h"
-#include "tulog.h"
-#include "tutil.h"
-
-int64_t str2int64(char *str) {
-  char *endptr = NULL;
-  return strtoll(str, &endptr, 10);
-}
-
-/*
-  to make taosMsleep work,
-   signal SIGALRM shall be blocked in the calling thread,
-
-  sigset_t set;
-  sigemptyset(&set);
-  sigaddset(&set, SIGALRM);
-  pthread_sigmask(SIG_BLOCK, &set, NULL);
-*/
-void taosMsleep(int mseconds) {
-  struct timeval timeout;
-  int            seconds, useconds;
-
-  seconds = mseconds / 1000;
-  useconds = (mseconds % 1000) * 1000;
-  timeout.tv_sec = seconds;
-  timeout.tv_usec = useconds;
-
-  /* sigset_t set; */
-  /* sigemptyset(&set); */
-  /* sigaddset(&set, SIGALRM); */
-  /* pthread_sigmask(SIG_BLOCK, &set, NULL); */
-
-  select(0, NULL, NULL, NULL, &timeout);
-
-  /* pthread_sigmask(SIG_UNBLOCK, &set, NULL); */
-}
-
-bool taosCheckPthreadValid(pthread_t thread) { return thread != 0; }
-
-int64_t taosGetPthreadId() { return (int64_t)pthread_self(); }
-
-int taosSetNonblocking(int sock, int on) {
-  int flags = 0;
-  if ((flags = fcntl(sock, F_GETFL, 0)) < 0) {
-    uError("fcntl(F_GETFL) error: %d (%s)\n", errno, strerror(errno));
-    return 1;
-  }
-
-  if (on)
-    flags |= O_NONBLOCK;
-  else
-    flags &= ~O_NONBLOCK;
-
-  if ((flags = fcntl(sock, F_SETFL, flags)) < 0) {
-    uError("fcntl(F_SETFL) error: %d (%s)\n", errno, strerror(errno));
-    return 1;
-  }
-
-  return 0;
-}
-
-int taosSetSockOpt(int socketfd, int level, int optname, void *optval, int optlen) {
-  return setsockopt(socketfd, level, optname, optval, (socklen_t)optlen);
-}
-static void taosDeleteTimer(void *tharg) {
-  timer_t *pTimer = tharg;
-  timer_delete(*pTimer);
-}
-
-static pthread_t timerThread;
-static timer_t         timerId;
-static volatile bool stopTimer = false;
-
-void *taosProcessAlarmSignal(void *tharg) {
-  // Block the signal
-  sigset_t sigset;
-  sigemptyset(&sigset);
-  sigaddset(&sigset, SIGALRM);
-  sigprocmask(SIG_BLOCK, &sigset, NULL);
-  void (*callback)(int) = tharg;
-
-  struct sigevent sevent = {{0}};
-
-  #ifdef _ALPINE
-    sevent.sigev_notify = SIGEV_THREAD;
-    sevent.sigev_value.sival_int = syscall(__NR_gettid);
-  #else
-    sevent.sigev_notify = SIGEV_THREAD_ID;
-    sevent._sigev_un._tid = syscall(__NR_gettid);
-  #endif
-  
-  sevent.sigev_signo = SIGALRM;
-
-  if (timer_create(CLOCK_REALTIME, &sevent, &timerId) == -1) {
-    uError("Failed to create timer");
-  }
-
-  pthread_cleanup_push(taosDeleteTimer, &timerId);
-
-  struct itimerspec ts;
-  ts.it_value.tv_sec = 0;
-  ts.it_value.tv_nsec = 1000000 * MSECONDS_PER_TICK;
-  ts.it_interval.tv_sec = 0;
-  ts.it_interval.tv_nsec = 1000000 * MSECONDS_PER_TICK;
-
-  if (timer_settime(timerId, 0, &ts, NULL)) {
-    uError("Failed to init timer");
-    return NULL;
-  }
-
-  int signo;
-  while (!stopTimer) {
-    if (sigwait(&sigset, &signo)) {
-      uError("Failed to wait signal: number %d", signo);
-      continue;
-    }
-    /* printf("Signal handling: number %d ......\n", signo); */
-
-    callback(0);
-  }
-  
-  pthread_cleanup_pop(1);
-
-  return NULL;
-}
-
-
-int taosInitTimer(void (*callback)(int), int ms) {
-  pthread_attr_t tattr;
-  pthread_attr_init(&tattr);
-  int code = pthread_create(&timerThread, &tattr, taosProcessAlarmSignal, callback);
-  pthread_attr_destroy(&tattr);
-  if (code != 0) {
-    uError("failed to create timer thread");
-    return -1;
-  }
-  return 0;
-}
-
-void taosUninitTimer() {
-  stopTimer = true;
-  pthread_join(timerThread, NULL);
-}
-
-ssize_t tread(int fd, void *buf, size_t count) {
-  size_t  leftbytes = count;
-  ssize_t readbytes;
-  char *  tbuf = (char *)buf;
-
-  while (leftbytes > 0) {
-    readbytes = read(fd, (void *)tbuf, leftbytes);
-    if (readbytes < 0) {
-      if (errno == EINTR) {
-        continue;
-      } else {
-        return -1;
-      }
-    } else if (readbytes == 0) {
-      return (ssize_t)(count - leftbytes);
-    }
-
-    leftbytes -= readbytes;
-    tbuf += readbytes;
-  }
-
-  return (ssize_t)count;
-}
-
-ssize_t tsendfile(int dfd, int sfd, off_t *offset, size_t size) {
-  size_t  leftbytes = size;
-  ssize_t sentbytes;
-
-  while (leftbytes > 0) {
-    /*
-     * TODO : Think to check if file is larger than 1GB
-     */
-    //if (leftbytes > 1000000000) leftbytes = 1000000000;
-    sentbytes = sendfile(dfd, sfd, offset, leftbytes);
-    if (sentbytes == -1) {
-      if (errno == EINTR) {
-        continue;
-      }
-      else {
-        return -1;
-      }
-    } else if (sentbytes == 0) {
-      return (ssize_t)(size - leftbytes);
-    }
-
-    leftbytes -= sentbytes;
-  }
-
-  return size;
-}
-
-ssize_t twrite(int fd, void *buf, size_t n) {
-  size_t nleft = n; 
-  ssize_t nwritten = 0;
-  char *tbuf = (char *)buf;
-
-  while (nleft > 0) {
-    nwritten = write(fd, (void *)tbuf, nleft);
-    if (nwritten < 0) {
-      if (errno == EINTR) {
-        continue;
-      }
-      return -1;
-    }
-    nleft -= nwritten;
-    tbuf += nwritten;
-  }
-
-  return n;
-}
-
-void taosBlockSIGPIPE() {
-  sigset_t signal_mask;
-  sigemptyset(&signal_mask);
-  sigaddset(&signal_mask, SIGPIPE);
-  int rc = pthread_sigmask(SIG_BLOCK, &signal_mask, NULL);
-  if (rc != 0) {
-    uError("failed to block SIGPIPE");
-  }
-}
-
-int tSystem(const char * cmd) 
-{ 
-  FILE * fp; 
-  int res; 
-  char buf[1024]; 
-  if (cmd == NULL) { 
-    uError("tSystem cmd is NULL!\n");
-    return -1;
-  } 
-  
-  if ((fp = popen(cmd, "r") ) == NULL) { 
-    uError("popen cmd:%s error: %s/n", cmd, strerror(errno)); 
-    return -1; 
-  } else {
-    while(fgets(buf, sizeof(buf), fp))  { 
-      uDebug("popen result:%s", buf); 
-    } 
-
-    if ((res = pclose(fp)) == -1) { 
-      uError("close popen file pointer fp error!\n");
-    } else { 
-      uDebug("popen res is :%d\n", res);
-    } 
-
-    return res;
-  }
-}
-
-#ifdef TAOS_RANDOM_NETWORK_FAIL
-
-#define RANDOM_NETWORK_FAIL_FACTOR  20
-
-ssize_t taos_send_random_fail(int sockfd, const void *buf, size_t len, int flags)
-{
-  if (rand() % RANDOM_NETWORK_FAIL_FACTOR == 0) {
-    errno = ECONNRESET;
-    return -1;
-  }
-
-  return send(sockfd, buf, len, flags);
-}
-
-ssize_t taos_sendto_random_fail(int sockfd, const void *buf, size_t len, int flags,
-                      const struct sockaddr *dest_addr, socklen_t addrlen)
-{
-  if (rand() % RANDOM_NETWORK_FAIL_FACTOR == 0) {
-    errno = ECONNRESET;
-    return -1;
-  }
-
-  return sendto(sockfd, buf, len, flags, dest_addr, addrlen);
-}
-
-ssize_t taos_read_random_fail(int fd, void *buf, size_t count)
-{
-  if (rand() % RANDOM_NETWORK_FAIL_FACTOR == 0) {
-    errno = ECONNRESET;
-    return -1;
-  }
-
-  return read(fd, buf, count);
-}
-
-ssize_t taos_write_random_fail(int fd, const void *buf, size_t count)
-{
-  if (rand() % RANDOM_NETWORK_FAIL_FACTOR == 0) {
-    errno = EINTR;
-    return -1;
-  }
-
-  return write(fd, buf, count);
-}
-
-#endif /* TAOS_RANDOM_NETWORK_FAIL */
diff --git a/src/os/src/alpine/CMakeLists.txt b/src/os/src/alpine/CMakeLists.txt
new file mode 100644
index 0000000000..79cbf917e2
--- /dev/null
+++ b/src/os/src/alpine/CMakeLists.txt
@@ -0,0 +1,12 @@
+CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
+PROJECT(TDengine)
+
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/common/inc)
+AUX_SOURCE_DIRECTORY(. SRC)
+
+ADD_LIBRARY(os ${SRC})
+TARGET_LINK_LIBRARIES(os m rt)
+
diff --git a/src/os/linux/src/linuxEnv.c b/src/os/src/alpine/alpineEnv.c
similarity index 100%
rename from src/os/linux/src/linuxEnv.c
rename to src/os/src/alpine/alpineEnv.c
diff --git a/src/os/linux/CMakeLists.txt b/src/os/src/darwin64/CMakeLists.txt
similarity index 61%
rename from src/os/linux/CMakeLists.txt
rename to src/os/src/darwin64/CMakeLists.txt
index 7be4a13f25..71029d9291 100644
--- a/src/os/linux/CMakeLists.txt
+++ b/src/os/src/darwin64/CMakeLists.txt
@@ -1,16 +1,13 @@
 CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
 PROJECT(TDengine)
 
-IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
-  INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
+IF (TD_DARWIN_64)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/common/inc)
   INCLUDE_DIRECTORIES(inc)
   AUX_SOURCE_DIRECTORY(src SRC)
-
   ADD_LIBRARY(os ${SRC})
-  TARGET_LINK_LIBRARIES(os m rt)
 ENDIF ()
 
-SET_SOURCE_FILES_PROPERTIES(src/linuxSysPara.c PROPERTIES COMPILE_FLAGS -w)
diff --git a/src/os/darwin/src/darwinEnv.c b/src/os/src/darwin64/darwinEnv.c
similarity index 100%
rename from src/os/darwin/src/darwinEnv.c
rename to src/os/src/darwin64/darwinEnv.c
diff --git a/src/os/darwin/src/darwinPlatform.c b/src/os/src/darwin64/darwinPlatform.c
similarity index 85%
rename from src/os/darwin/src/darwinPlatform.c
rename to src/os/src/darwin64/darwinPlatform.c
index 44540cf69e..045e4a7099 100644
--- a/src/os/darwin/src/darwinPlatform.c
+++ b/src/os/src/darwin64/darwinPlatform.c
@@ -15,12 +15,15 @@
 
 #define _DEFAULT_SOURCE
 #include "os.h"
-#include "tglobal.h"
+#include "os.h"
 #include "taosdef.h"
-#include "tutil.h"
+#include "tglobal.h"
+#include "tconfig.h"
+#include "ttimer.h"
 #include "tulog.h"
+#include "tutil.h"
 
-int64_t str2int64(char *str) {
+int64_t tsosStr2int64(char *str) {
   char *endptr = NULL;
   return strtoll(str, &endptr, 10);
 }
@@ -159,12 +162,14 @@ int taosInitTimer(void (*callback)(int), int ms) {
   tv.it_interval.tv_usec = 1000 * ms;  // resolution is in msecond
   tv.it_value = tv.it_interval;
 
-  return setitimer(ITIMER_REAL, &tv, NULL);
+  setitimer(ITIMER_REAL, &tv, NULL);
+
+  return 0;
 }
 
 void taosUninitTimer() {
   struct itimerval tv = { 0 };
-  return setitimer(ITIMER_REAL, &tv, NULL);
+  setitimer(ITIMER_REAL, &tv, NULL);
 }
 
 void taosGetSystemTimezone() {
@@ -207,7 +212,7 @@ void taosGetSystemLocale() {
 void taosPrintOsInfo() {}
 
 void taosKillSystem() {
-  tError("function taosKillSystem, exit!");
+  uError("function taosKillSystem, exit!");
   exit(0);
 }
 
@@ -221,95 +226,75 @@ void taosGetSystemInfo() {
 }
 
 void *taosInitTcpClient(char *ip, uint16_t port, char *flabel, int num, void *fp, void *shandle) {
-  tError("function taosInitTcpClient is not implemented in darwin system, exit!");
+  uError("function taosInitTcpClient is not implemented in darwin system, exit!");
   exit(0);
 }
 
 void taosCloseTcpClientConnection(void *chandle) {
-  tError("function taosCloseTcpClientConnection is not implemented in darwin system, exit!");
+  uError("function taosCloseTcpClientConnection is not implemented in darwin system, exit!");
   exit(0);
 }
 
 void *taosOpenTcpClientConnection(void *shandle, void *thandle, char *ip, uint16_t port) {
-  tError("function taosOpenTcpClientConnection is not implemented in darwin system, exit!");
+  uError("function taosOpenTcpClientConnection is not implemented in darwin system, exit!");
   exit(0);
 }
 
 int taosSendTcpClientData(unsigned int ip, uint16_t port, char *data, int len, void *chandle) {
-  tError("function taosSendTcpClientData is not implemented in darwin system, exit!");
+  uError("function taosSendTcpClientData is not implemented in darwin system, exit!");
   exit(0);
 }
 
 void taosCleanUpTcpClient(void *chandle) {
-  tError("function taosCleanUpTcpClient is not implemented in darwin system, exit!");
+  uError("function taosCleanUpTcpClient is not implemented in darwin system, exit!");
   exit(0);
 }
 
 void taosCloseTcpServerConnection(void *chandle) {
-  tError("function taosCloseTcpServerConnection is not implemented in darwin system, exit!");
+  uError("function taosCloseTcpServerConnection is not implemented in darwin system, exit!");
   exit(0);
 }
 
 void taosCleanUpTcpServer(void *handle) {
-  tError("function taosCleanUpTcpServer is not implemented in darwin system, exit!");
+  uError("function taosCleanUpTcpServer is not implemented in darwin system, exit!");
   exit(0);
 }
 
 void *taosInitTcpServer(char *ip, uint16_t port, char *label, int numOfThreads, void *fp, void *shandle) {
-  tError("function taosInitTcpServer is not implemented in darwin system, exit!");
+  uError("function taosInitTcpServer is not implemented in darwin system, exit!");
   exit(0);
 }
 
 int taosSendTcpServerData(unsigned int ip, uint16_t port, char *data, int len, void *chandle) {
-  tError("function taosSendTcpServerData is not implemented in darwin system, exit!");
+  uError("function taosSendTcpServerData is not implemented in darwin system, exit!");
   exit(0);
 }
 
 void taosFreeMsgHdr(void *hdr) {
-  tError("function taosFreeMsgHdr is not implemented in darwin system, exit!");
+  uError("function taosFreeMsgHdr is not implemented in darwin system, exit!");
   exit(0);
 }
 
 int taosMsgHdrSize(void *hdr) {
-  tError("function taosMsgHdrSize is not implemented in darwin system, exit!");
+  uError("function taosMsgHdrSize is not implemented in darwin system, exit!");
   exit(0);
 }
 
 void taosSendMsgHdr(void *hdr, int fd) {
-  tError("function taosSendMsgHdr is not implemented in darwin system, exit!");
+  uError("function taosSendMsgHdr is not implemented in darwin system, exit!");
   exit(0);
 }
 
 void taosInitMsgHdr(void **hdr, void *dest, int maxPkts) {
-  tError("function taosInitMsgHdr is not implemented in darwin system, exit!");
+  uError("function taosInitMsgHdr is not implemented in darwin system, exit!");
   exit(0);
 }
 
 void taosSetMsgHdrData(void *hdr, char *data, int dataLen) {
-  tError("function taosSetMsgHdrData is not implemented in darwin system, exit!");
+  uError("function taosSetMsgHdrData is not implemented in darwin system, exit!");
   exit(0);
 }
 
-ssize_t twrite(int fd, void *buf, size_t n) {
-  size_t nleft = n; 
-  ssize_t nwritten = 0;
-  char *tbuf = (char *)buf;
-
-  while (nleft > 0) {
-    nwritten = write(fd, (void *)tbuf, nleft);
-    if (nwritten < 0) {
-      if (errno == EINTR) {
-        continue;
-      }
-      return -1;
-    }
-    nleft -= nwritten;
-    tbuf += nwritten;
-  }
-
-  return n;
-}
-
 bool taosSkipSocketCheck() {
   return true;
 }
diff --git a/src/os/src/detail/CMakeLists.txt b/src/os/src/detail/CMakeLists.txt
new file mode 100644
index 0000000000..5902a9356b
--- /dev/null
+++ b/src/os/src/detail/CMakeLists.txt
@@ -0,0 +1,14 @@
+CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
+PROJECT(TDengine)
+
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/common/inc)
+INCLUDE_DIRECTORIES(.)
+AUX_SOURCE_DIRECTORY(. SRC)
+SET_SOURCE_FILES_PROPERTIES(osSysinfo.c PROPERTIES COMPILE_FLAGS -w)
+SET_SOURCE_FILES_PROPERTIES(osCoredump.c PROPERTIES COMPILE_FLAGS -w)
+
+ADD_LIBRARY(osdetail ${SRC})
+TARGET_LINK_LIBRARIES(osdetail os)
diff --git a/src/os/src/detail/osCoredump.c b/src/os/src/detail/osCoredump.c
new file mode 100644
index 0000000000..fe97000c7d
--- /dev/null
+++ b/src/os/src/detail/osCoredump.c
@@ -0,0 +1,98 @@
+/*
+ * 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 "os.h"
+#include "tconfig.h"
+#include "tglobal.h"
+#include "tulog.h"
+#include "tutil.h"
+#include "tsystem.h"
+
+#ifndef TAOS_OS_FUNC_CORE
+
+int _sysctl(struct __sysctl_args *args );
+
+void taosSetCoreDump() {
+  if (0 == tsEnableCoreFile) {
+    return;
+  }
+  
+  // 1. set ulimit -c unlimited
+  struct rlimit rlim;
+  struct rlimit rlim_new;
+  if (getrlimit(RLIMIT_CORE, &rlim) == 0) {
+    uInfo("the old unlimited para: rlim_cur=%" PRIu64 ", rlim_max=%" PRIu64, rlim.rlim_cur, rlim.rlim_max);
+    rlim_new.rlim_cur = RLIM_INFINITY;
+    rlim_new.rlim_max = RLIM_INFINITY;
+    if (setrlimit(RLIMIT_CORE, &rlim_new) != 0) {
+      uInfo("set unlimited fail, error: %s", strerror(errno));
+      rlim_new.rlim_cur = rlim.rlim_max;
+      rlim_new.rlim_max = rlim.rlim_max;
+      (void)setrlimit(RLIMIT_CORE, &rlim_new);
+    }
+  }
+
+  if (getrlimit(RLIMIT_CORE, &rlim) == 0) {
+    uInfo("the new unlimited para: rlim_cur=%" PRIu64 ", rlim_max=%" PRIu64, rlim.rlim_cur, rlim.rlim_max);
+  }
+
+#ifndef _TD_ARM_
+  // 2. set the path for saving core file
+  struct __sysctl_args args;
+  int     old_usespid = 0;
+  size_t  old_len     = 0;
+  int     new_usespid = 1;
+  size_t  new_len     = sizeof(new_usespid);
+  
+  int name[] = {CTL_KERN, KERN_CORE_USES_PID};
+  
+  memset(&args, 0, sizeof(struct __sysctl_args));
+  args.name    = name;
+  args.nlen    = sizeof(name)/sizeof(name[0]);
+  args.oldval  = &old_usespid;
+  args.oldlenp = &old_len;
+  args.newval  = &new_usespid;
+  args.newlen  = new_len;
+  
+  old_len = sizeof(old_usespid);
+  
+  if (syscall(SYS__sysctl, &args) == -1) {
+      uInfo("_sysctl(kern_core_uses_pid) set fail: %s", strerror(errno));
+  }
+  
+  uInfo("The old core_uses_pid[%" PRIu64 "]: %d", old_len, old_usespid);
+
+
+  old_usespid = 0;
+  old_len     = 0;
+  memset(&args, 0, sizeof(struct __sysctl_args));
+  args.name    = name;
+  args.nlen    = sizeof(name)/sizeof(name[0]);
+  args.oldval  = &old_usespid;
+  args.oldlenp = &old_len;
+  
+  old_len = sizeof(old_usespid);
+  
+  if (syscall(SYS__sysctl, &args) == -1) {
+      uInfo("_sysctl(kern_core_uses_pid) get fail: %s", strerror(errno));
+  }
+  
+  uInfo("The new core_uses_pid[%" PRIu64 "]: %d", old_len, old_usespid);
+#endif
+
+}
+
+#endif
\ No newline at end of file
diff --git a/src/util/src/tfile.c b/src/os/src/detail/osFail.c
similarity index 55%
rename from src/util/src/tfile.c
rename to src/os/src/detail/osFail.c
index d1a9c24615..e0eb200851 100644
--- a/src/util/src/tfile.c
+++ b/src/os/src/detail/osFail.c
@@ -13,31 +13,62 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include <stdio.h>
-#include <stdlib.h>
-#include <error.h>
-#include <errno.h>
-#include <stdarg.h>
-#include <unistd.h>
-
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-
+#define _DEFAULT_SOURCE
 #include "os.h"
 
+#define RANDOM_NETWORK_FAIL_FACTOR  20
+
+#ifdef TAOS_RANDOM_NETWORK_FAIL
+
+ssize_t taosSendRandomFail(int sockfd, const void *buf, size_t len, int flags) {
+  if (rand() % RANDOM_NETWORK_FAIL_FACTOR == 0) {
+    errno = ECONNRESET;
+    return -1;
+  }
+
+  return send(sockfd, buf, len, flags);
+}
+
+ssize_t taosSendToRandomFail(int sockfd, const void *buf, size_t len, int flags, const struct sockaddr *dest_addr,
+                           socklen_t addrlen) {
+  if (rand() % RANDOM_NETWORK_FAIL_FACTOR == 0) {
+    errno = ECONNRESET;
+    return -1;
+  }
+
+  return sendto(sockfd, buf, len, flags, dest_addr, addrlen);
+}
+
+ssize_t taosReadSocketRandomFail(int fd, void *buf, size_t count) {
+  if (rand() % RANDOM_NETWORK_FAIL_FACTOR == 0) {
+    errno = ECONNRESET;
+    return -1;
+  }
+
+  return read(fd, buf, count);
+}
+
+ssize_t taosWriteSocketRandomFail(int fd, const void *buf, size_t count) {
+  if (rand() % RANDOM_NETWORK_FAIL_FACTOR == 0) {
+    errno = EINTR;
+    return -1;
+  }
+
+  return write(fd, buf, count);
+}
+
+#endif //TAOS_RANDOM_NETWORK_FAIL
+
 #ifdef TAOS_RANDOM_FILE_FAIL
 
 static int random_file_fail_factor = 20;
 static FILE *fpRandomFileFailOutput = NULL;
 
-void taosSetRandomFileFailFactor(int factor)
-{
+void taosSetRandomFileFailFactor(int factor) { 
   random_file_fail_factor = factor;
 }
 
-static void close_random_file_fail_output()
-{
+static void close_random_file_fail_output() {
   if (fpRandomFileFailOutput != NULL) {
     if (fpRandomFileFailOutput != stdout) {
       fclose(fpRandomFileFailOutput);
@@ -46,8 +77,7 @@ static void close_random_file_fail_output()
   }
 }
 
-static void random_file_fail_output_sig(int sig)
-{
+static void random_file_fail_output_sig(int sig) {
   fprintf(fpRandomFileFailOutput, "signal %d received.\n", sig);
 
   struct sigaction act = {0};
@@ -58,8 +88,7 @@ static void random_file_fail_output_sig(int sig)
   exit(EXIT_FAILURE);
 }
 
-void taosSetRandomFileFailOutput(const char *path)
-{
+void taosSetRandomFileFailOutput(const char *path) {
   if (path == NULL) {
     fpRandomFileFailOutput = stdout;
   } else if ((fpRandomFileFailOutput = fopen(path, "w")) != NULL) {
@@ -75,43 +104,38 @@ void taosSetRandomFileFailOutput(const char *path)
   sigaction(SIGSEGV, &act, NULL);
   sigaction(SIGILL, &act, NULL);
 }
-#endif
 
-ssize_t taos_tread(int fd, void *buf, size_t count, const char *file, uint32_t line)
-{
-#ifdef TAOS_RANDOM_FILE_FAIL
+ssize_t taosReadFileRandomFail(int fd, void *buf, size_t count, const char *file, uint32_t line) {
   if (random_file_fail_factor > 0) {
     if (rand() % random_file_fail_factor == 0) {
       errno = EIO;
       return -1;
     }
   }
-#endif
-  return tread(fd, buf, count);
+
+  return taosTReadImp(fd, buf, count);
 }
 
-ssize_t taos_twrite(int fd, void *buf, size_t count, const char *file, uint32_t line)
-{
-#ifdef TAOS_RANDOM_FILE_FAIL
+ssize_t taosWriteFileRandomFail(int fd, void *buf, size_t count, const char *file, uint32_t line) {
   if (random_file_fail_factor > 0) {
     if (rand() % random_file_fail_factor == 0) {
       errno = EIO;
       return -1;
     }
   }
-#endif
-  return twrite(fd, buf, count);
+
+  return taosTWriteImp(fd, buf, count);
 }
 
-off_t taos_lseek(int fd, off_t offset, int whence, const char *file, uint32_t line)
-{
-#ifdef TAOS_RANDOM_FILE_FAIL
+off_t taosLSeekRandomFail(int fd, off_t offset, int whence, const char *file, uint32_t line) {
   if (random_file_fail_factor > 0) {
     if (rand() % random_file_fail_factor == 0) {
       errno = EIO;
       return -1;
     }
   }
-#endif
+
   return lseek(fd, offset, whence);
 }
+
+#endif //TAOS_RANDOM_FILE_FAIL
diff --git a/src/os/src/detail/osFile.c b/src/os/src/detail/osFile.c
new file mode 100644
index 0000000000..897b6c3f03
--- /dev/null
+++ b/src/os/src/detail/osFile.c
@@ -0,0 +1,88 @@
+/*
+ * 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 "os.h"
+
+ssize_t taosTReadImp(int fd, void *buf, size_t count) {
+  size_t  leftbytes = count;
+  ssize_t readbytes;
+  char *  tbuf = (char *)buf;
+
+  while (leftbytes > 0) {
+    readbytes = read(fd, (void *)tbuf, leftbytes);
+    if (readbytes < 0) {
+      if (errno == EINTR) {
+        continue;
+      } else {
+        return -1;
+      }
+    } else if (readbytes == 0) {
+      return (ssize_t)(count - leftbytes);
+    }
+
+    leftbytes -= readbytes;
+    tbuf += readbytes;
+  }
+
+  return (ssize_t)count;
+}
+
+ssize_t taosTSendFileImp(int dfd, int sfd, off_t *offset, size_t size) {
+  size_t  leftbytes = size;
+  ssize_t sentbytes;
+
+  while (leftbytes > 0) {
+    /*
+     * TODO : Think to check if file is larger than 1GB
+     */
+    //if (leftbytes > 1000000000) leftbytes = 1000000000;
+    sentbytes = sendfile(dfd, sfd, offset, leftbytes);
+    if (sentbytes == -1) {
+      if (errno == EINTR) {
+        continue;
+      }
+      else {
+        return -1;
+      }
+    } else if (sentbytes == 0) {
+      return (ssize_t)(size - leftbytes);
+    }
+
+    leftbytes -= sentbytes;
+  }
+
+  return size;
+}
+
+ssize_t taosTWriteImp(int fd, void *buf, size_t n) {
+  size_t nleft = n; 
+  ssize_t nwritten = 0;
+  char *tbuf = (char *)buf;
+
+  while (nleft > 0) {
+    nwritten = write(fd, (void *)tbuf, nleft);
+    if (nwritten < 0) {
+      if (errno == EINTR) {
+        continue;
+      }
+      return -1;
+    }
+    nleft -= nwritten;
+    tbuf += nwritten;
+  }
+
+  return n;
+}
diff --git a/src/os/src/detail/osPThread.c b/src/os/src/detail/osPThread.c
new file mode 100644
index 0000000000..18207dc12e
--- /dev/null
+++ b/src/os/src/detail/osPThread.c
@@ -0,0 +1,24 @@
+/*
+ * 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 "os.h"
+
+#ifndef TAOS_OS_FUNC_PTHREAD
+
+bool    taosCheckPthreadValid(pthread_t thread) { return thread != 0; }
+int64_t taosGetPthreadId() { return (int64_t)pthread_self(); }
+
+#endif
\ No newline at end of file
diff --git a/src/os/src/detail/osSocket.c b/src/os/src/detail/osSocket.c
new file mode 100644
index 0000000000..ea0b92de5f
--- /dev/null
+++ b/src/os/src/detail/osSocket.c
@@ -0,0 +1,56 @@
+/*
+ * 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 "os.h"
+#include "tulog.h"
+
+#ifndef TAOS_OS_FUNC_SOCKET
+
+int taosSetNonblocking(int sock, int on) {
+  int flags = 0;
+  if ((flags = fcntl(sock, F_GETFL, 0)) < 0) {
+    uError("fcntl(F_GETFL) error: %d (%s)\n", errno, strerror(errno));
+    return 1;
+  }
+
+  if (on)
+    flags |= O_NONBLOCK;
+  else
+    flags &= ~O_NONBLOCK;
+
+  if ((flags = fcntl(sock, F_SETFL, flags)) < 0) {
+    uError("fcntl(F_SETFL) error: %d (%s)\n", errno, strerror(errno));
+    return 1;
+  }
+
+  return 0;
+}
+
+int taosSetSockOpt(int socketfd, int level, int optname, void *optval, int optlen) {
+  return setsockopt(socketfd, level, optname, optval, (socklen_t)optlen);
+}
+
+void taosBlockSIGPIPE() {
+  sigset_t signal_mask;
+  sigemptyset(&signal_mask);
+  sigaddset(&signal_mask, SIGPIPE);
+  int rc = pthread_sigmask(SIG_BLOCK, &signal_mask, NULL);
+  if (rc != 0) {
+    uError("failed to block SIGPIPE");
+  }
+}
+
+#endif
\ No newline at end of file
diff --git a/src/os/linux/src/linuxSysPara.c b/src/os/src/detail/osSysinfo.c
similarity index 79%
rename from src/os/linux/src/linuxSysPara.c
rename to src/os/src/detail/osSysinfo.c
index 1331503619..ac9b441555 100644
--- a/src/os/linux/src/linuxSysPara.c
+++ b/src/os/src/detail/osSysinfo.c
@@ -15,13 +15,14 @@
 
 #define _DEFAULT_SOURCE
 #include "os.h"
-#include "tsysctl.h"
 #include "tconfig.h"
 #include "tglobal.h"
 #include "tulog.h"
 #include "tutil.h"
 #include "tsystem.h"
 
+#ifndef TAOS_OS_FUNC_SYSINFO
+
 #define PROCESS_ITEM 12
 
 typedef struct {
@@ -200,7 +201,7 @@ static void taosGetSystemTimezone() {
    * Asia/Shanghai   (CST, +0800)
    * Europe/London   (BST, +0100)
    */
-  sprintf(tsTimezone, "%s (%s, %s%02d00)", buf, tzname[daylight], tz >= 0 ? "+" : "-", abs(tz));
+  snprintf(tsTimezone, TSDB_TIMEZONE_LEN, "%s (%s, %s%02d00)", buf, tzname[daylight], tz >= 0 ? "+" : "-", abs(tz));
 
   // cfg_timezone->cfgStatus = TAOS_CFG_CSTATUS_DEFAULT;
   uInfo("timezone not configured, set to system default:%s", tsTimezone);
@@ -234,7 +235,7 @@ static void taosGetSystemLocale() {  // get and set default locale
       uError("can't get locale from system, set it to en_US.UTF-8");
       strcpy(tsLocale, "en_US.UTF-8");
     } else {
-      tstrncpy(tsLocale, locale, sizeof(tsLocale));
+      tstrncpy(tsLocale, locale, TSDB_LOCALE_LEN);
       uError("locale not configured, set to system default:%s", tsLocale);
     }
   }
@@ -247,7 +248,7 @@ static void taosGetSystemLocale() {  // get and set default locale
       str++;
 
       char *revisedCharset = taosCharsetReplace(str);
-      tstrncpy(tsCharset, revisedCharset, sizeof(tsCharset));
+      tstrncpy(tsCharset, revisedCharset, TSDB_LOCALE_LEN);
 
       free(revisedCharset);
       uWarn("charset not configured, set to system default:%s", tsCharset);
@@ -542,126 +543,31 @@ void taosKillSystem() {
   kill(tsProcId, 2);
 }
 
-int _sysctl(struct __sysctl_args *args );
-void taosSetCoreDump() {
-  if (0 == tsEnableCoreFile) {
-    return;
+int tSystem(const char *cmd) {
+  FILE *fp;
+  int   res;
+  char  buf[1024];
+  if (cmd == NULL) {
+    uError("tSystem cmd is NULL!\n");
+    return -1;
   }
-  
-  // 1. set ulimit -c unlimited
-  struct rlimit rlim;
-  struct rlimit rlim_new;
-  if (getrlimit(RLIMIT_CORE, &rlim) == 0) {
-    uInfo("the old unlimited para: rlim_cur=%" PRIu64 ", rlim_max=%" PRIu64, rlim.rlim_cur, rlim.rlim_max);
-    rlim_new.rlim_cur = RLIM_INFINITY;
-    rlim_new.rlim_max = RLIM_INFINITY;
-    if (setrlimit(RLIMIT_CORE, &rlim_new) != 0) {
-      uInfo("set unlimited fail, error: %s", strerror(errno));
-      rlim_new.rlim_cur = rlim.rlim_max;
-      rlim_new.rlim_max = rlim.rlim_max;
-      (void)setrlimit(RLIMIT_CORE, &rlim_new);
+
+  if ((fp = popen(cmd, "r")) == NULL) {
+    uError("popen cmd:%s error: %s/n", cmd, strerror(errno));
+    return -1;
+  } else {
+    while (fgets(buf, sizeof(buf), fp)) {
+      uDebug("popen result:%s", buf);
     }
-  }
 
-  if (getrlimit(RLIMIT_CORE, &rlim) == 0) {
-    uInfo("the new unlimited para: rlim_cur=%" PRIu64 ", rlim_max=%" PRIu64, rlim.rlim_cur, rlim.rlim_max);
-  }
-
-#ifndef _TD_ARM_
-  // 2. set the path for saving core file
-  struct __sysctl_args args;
-  int     old_usespid = 0;
-  size_t  old_len     = 0;
-  int     new_usespid = 1;
-  size_t  new_len     = sizeof(new_usespid);
-  
-  int name[] = {CTL_KERN, KERN_CORE_USES_PID};
-  
-  memset(&args, 0, sizeof(struct __sysctl_args));
-  args.name    = name;
-  args.nlen    = sizeof(name)/sizeof(name[0]);
-  args.oldval  = &old_usespid;
-  args.oldlenp = &old_len;
-  args.newval  = &new_usespid;
-  args.newlen  = new_len;
-  
-  old_len = sizeof(old_usespid);
-  
-  if (syscall(SYS__sysctl, &args) == -1) {
-      uInfo("_sysctl(kern_core_uses_pid) set fail: %s", strerror(errno));
-  }
-  
-  uInfo("The old core_uses_pid[%" PRIu64 "]: %d", old_len, old_usespid);
-
-
-  old_usespid = 0;
-  old_len     = 0;
-  memset(&args, 0, sizeof(struct __sysctl_args));
-  args.name    = name;
-  args.nlen    = sizeof(name)/sizeof(name[0]);
-  args.oldval  = &old_usespid;
-  args.oldlenp = &old_len;
-  
-  old_len = sizeof(old_usespid);
-  
-  if (syscall(SYS__sysctl, &args) == -1) {
-      uInfo("_sysctl(kern_core_uses_pid) get fail: %s", strerror(errno));
-  }
-  
-  uInfo("The new core_uses_pid[%" PRIu64 "]: %d", old_len, old_usespid);
-#endif
-  
-#if 0
-  // 3. create the path for saving core file
-  int status; 
-  char coredump_dir[32] = "/var/log/taosdump";
-  if (opendir(coredump_dir) == NULL) {
-    status = mkdir(coredump_dir, S_IRWXU | S_IRWXG | S_IRWXO); 
-    if (status) {
-      uInfo("mkdir fail, error: %s\n", strerror(errno));
+    if ((res = pclose(fp)) == -1) {
+      uError("close popen file pointer fp error!\n");
+    } else {
+      uDebug("popen res is :%d\n", res);
     }
+
+    return res;
   }
-
-  // 4. set kernel.core_pattern
-   struct __sysctl_args args;
-   char    old_corefile[128];
-   size_t  old_len;
-   char    new_corefile[128] = "/var/log/taosdump/core-%e-%p";
-   size_t  new_len = sizeof(new_corefile);
-   
-   int name[] = {CTL_KERN, KERN_CORE_PATTERN};
-
-   memset(&args, 0, sizeof(struct __sysctl_args));
-   args.name    = name;
-   args.nlen    = sizeof(name)/sizeof(name[0]);
-   args.oldval  = old_corefile;
-   args.oldlenp = &old_len;
-   args.newval  = new_corefile;
-   args.newlen  = new_len;
-
-   old_len = sizeof(old_corefile);
-
-   if (syscall(SYS__sysctl, &args) == -1) {
-       uInfo("_sysctl(kern_core_pattern) set fail: %s", strerror(errno));
-   }
-   
-   uInfo("The old kern_core_pattern: %*s\n", old_len, old_corefile);
-
-
-   memset(&args, 0, sizeof(struct __sysctl_args));
-   args.name    = name;
-   args.nlen    = sizeof(name)/sizeof(name[0]);
-   args.oldval  = old_corefile;
-   args.oldlenp = &old_len;
-   
-   old_len = sizeof(old_corefile);
-
-   if (syscall(SYS__sysctl, &args) == -1) {
-       uInfo("_sysctl(kern_core_pattern) get fail: %s", strerror(errno));
-   }
-   
-   uInfo("The new kern_core_pattern: %*s\n", old_len, old_corefile);
-#endif
-  
 }
 
+#endif
\ No newline at end of file
diff --git a/src/os/src/detail/osTimer.c b/src/os/src/detail/osTimer.c
new file mode 100644
index 0000000000..843c29fcb0
--- /dev/null
+++ b/src/os/src/detail/osTimer.c
@@ -0,0 +1,133 @@
+/*
+ * 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 "os.h"
+#include "taosdef.h"
+#include "tglobal.h"
+#include "ttimer.h"
+#include "tulog.h"
+#include "tutil.h"
+#include <signal.h>
+
+#ifndef TAOS_OS_FUNC_TIMER
+
+/*
+  to make taosMsleep work,
+   signal SIGALRM shall be blocked in the calling thread,
+
+  sigset_t set;
+  sigemptyset(&set);
+  sigaddset(&set, SIGALRM);
+  pthread_sigmask(SIG_BLOCK, &set, NULL);
+*/
+void taosMsleep(int mseconds) {
+  struct timeval timeout;
+  int            seconds, useconds;
+
+  seconds = mseconds / 1000;
+  useconds = (mseconds % 1000) * 1000;
+  timeout.tv_sec = seconds;
+  timeout.tv_usec = useconds;
+
+  /* sigset_t set; */
+  /* sigemptyset(&set); */
+  /* sigaddset(&set, SIGALRM); */
+  /* pthread_sigmask(SIG_BLOCK, &set, NULL); */
+
+  select(0, NULL, NULL, NULL, &timeout);
+
+  /* pthread_sigmask(SIG_UNBLOCK, &set, NULL); */
+}
+
+
+static void taosDeleteTimer(void *tharg) {
+  timer_t *pTimer = tharg;
+  timer_delete(*pTimer);
+}
+
+static pthread_t timerThread;
+static timer_t         timerId;
+static volatile bool stopTimer = false;
+static void *taosProcessAlarmSignal(void *tharg) {
+  // Block the signal
+  sigset_t sigset;
+  sigemptyset(&sigset);
+  sigaddset(&sigset, SIGALRM);
+  sigprocmask(SIG_BLOCK, &sigset, NULL);
+  void (*callback)(int) = tharg;
+
+  struct sigevent sevent = {{0}};
+
+  #ifdef _ALPINE
+    sevent.sigev_notify = SIGEV_THREAD;
+    sevent.sigev_value.sival_int = syscall(__NR_gettid);
+  #else
+    sevent.sigev_notify = SIGEV_THREAD_ID;
+    sevent._sigev_un._tid = syscall(__NR_gettid);
+  #endif
+  
+  sevent.sigev_signo = SIGALRM;
+
+  if (timer_create(CLOCK_REALTIME, &sevent, &timerId) == -1) {
+    uError("Failed to create timer");
+  }
+
+  pthread_cleanup_push(taosDeleteTimer, &timerId);
+
+  struct itimerspec ts;
+  ts.it_value.tv_sec = 0;
+  ts.it_value.tv_nsec = 1000000 * MSECONDS_PER_TICK;
+  ts.it_interval.tv_sec = 0;
+  ts.it_interval.tv_nsec = 1000000 * MSECONDS_PER_TICK;
+
+  if (timer_settime(timerId, 0, &ts, NULL)) {
+    uError("Failed to init timer");
+    return NULL;
+  }
+
+  int signo;
+  while (!stopTimer) {
+    if (sigwait(&sigset, &signo)) {
+      uError("Failed to wait signal: number %d", signo);
+      continue;
+    }
+    /* printf("Signal handling: number %d ......\n", signo); */
+
+    callback(0);
+  }
+  
+  pthread_cleanup_pop(1);
+
+  return NULL;
+}
+
+int taosInitTimer(void (*callback)(int), int ms) {
+  pthread_attr_t tattr;
+  pthread_attr_init(&tattr);
+  int code = pthread_create(&timerThread, &tattr, taosProcessAlarmSignal, callback);
+  pthread_attr_destroy(&tattr);
+  if (code != 0) {
+    uError("failed to create timer thread");
+    return -1;
+  }
+  return 0;
+}
+
+void taosUninitTimer() {
+  stopTimer = true;
+  pthread_join(timerThread, NULL);
+}
+
+#endif
\ No newline at end of file
diff --git a/src/os/linux/inc/tsysctl.h b/src/os/src/detail/osUtil.c
similarity index 75%
rename from src/os/linux/inc/tsysctl.h
rename to src/os/src/detail/osUtil.c
index 559d5653ee..10576c9a0a 100644
--- a/src/os/linux/inc/tsysctl.h
+++ b/src/os/src/detail/osUtil.c
@@ -13,18 +13,14 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef TDENGINE_TSYSCTL_H
-#define TDENGINE_TSYSCTL_H
+#define _DEFAULT_SOURCE
+#include "os.h"
 
-#ifdef __cplusplus
-extern "C" {
-#endif
+#ifndef TAOS_OS_FUNC_UTIL
 
-#ifndef _ALPINE
-  #include <error.h>
-  #include <sys/sysctl.h>
-#else
-  #include <linux/sysctl.h>  
-#endif
+int64_t tsosStr2int64(char *str) {
+  char *endptr = NULL;
+  return strtoll(str, &endptr, 10);
+}
 
-#endif
+#endif
\ No newline at end of file
diff --git a/src/os/src/linux64/CMakeLists.txt b/src/os/src/linux64/CMakeLists.txt
new file mode 100644
index 0000000000..79cbf917e2
--- /dev/null
+++ b/src/os/src/linux64/CMakeLists.txt
@@ -0,0 +1,12 @@
+CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
+PROJECT(TDengine)
+
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/common/inc)
+AUX_SOURCE_DIRECTORY(. SRC)
+
+ADD_LIBRARY(os ${SRC})
+TARGET_LINK_LIBRARIES(os m rt)
+
diff --git a/src/os/src/linux64/linuxEnv.c b/src/os/src/linux64/linuxEnv.c
new file mode 100644
index 0000000000..0a9d81311a
--- /dev/null
+++ b/src/os/src/linux64/linuxEnv.c
@@ -0,0 +1,30 @@
+/*
+ * 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 "os.h"
+#include "tglobal.h"
+#include "tulog.h"
+
+void osInit() {
+  strcpy(configDir, "/etc/taos");
+  strcpy(tsVnodeDir, "");
+  strcpy(tsDnodeDir, "");
+  strcpy(tsMnodeDir, "");
+  strcpy(tsDataDir, "/var/lib/taos");
+  strcpy(tsLogDir, "/var/log/taos");
+  strcpy(tsScriptDir, "/etc/taos");
+  strcpy(tsOsName, "Linux");
+}
\ No newline at end of file
diff --git a/src/os/windows/CMakeLists.txt b/src/os/src/windows64/CMakeLists.txt
similarity index 100%
rename from src/os/windows/CMakeLists.txt
rename to src/os/src/windows64/CMakeLists.txt
diff --git a/src/os/windows/src/twindows.c b/src/os/src/windows64/twindows.c
similarity index 99%
rename from src/os/windows/src/twindows.c
rename to src/os/src/windows64/twindows.c
index 295824846e..4284dcb14e 100644
--- a/src/os/windows/src/twindows.c
+++ b/src/os/src/windows64/twindows.c
@@ -398,7 +398,7 @@ char *strndup(const char *s, size_t n) {
 void taosSetCoreDump() {}
 
 #ifdef _TD_GO_DLL_
-int64_t str2int64(char *str) {
+int64_t tsosStr2int64(char *str) {
   char *endptr = NULL;
   return strtoll(str, &endptr, 10);
 }
diff --git a/src/os/windows/src/twinenv.c b/src/os/src/windows64/twinenv.c
similarity index 100%
rename from src/os/windows/src/twinenv.c
rename to src/os/src/windows64/twinenv.c
diff --git a/src/os/windows/src/twingetline.c b/src/os/src/windows64/twingetline.c
similarity index 100%
rename from src/os/windows/src/twingetline.c
rename to src/os/src/windows64/twingetline.c
diff --git a/src/os/windows/src/twinmsghdr.c b/src/os/src/windows64/twinmsghdr.c
similarity index 100%
rename from src/os/windows/src/twinmsghdr.c
rename to src/os/src/windows64/twinmsghdr.c
diff --git a/src/os/windows/src/twinsocket.c b/src/os/src/windows64/twinsocket.c
similarity index 100%
rename from src/os/windows/src/twinsocket.c
rename to src/os/src/windows64/twinsocket.c
diff --git a/src/os/windows/src/twinstrptime.c b/src/os/src/windows64/twinstrptime.c
similarity index 100%
rename from src/os/windows/src/twinstrptime.c
rename to src/os/src/windows64/twinstrptime.c
diff --git a/src/os/windows/src/twintcpclient.c b/src/os/src/windows64/twintcpclient.c
similarity index 100%
rename from src/os/windows/src/twintcpclient.c
rename to src/os/src/windows64/twintcpclient.c
diff --git a/src/os/windows/src/twintcpserver.c b/src/os/src/windows64/twintcpserver.c
similarity index 100%
rename from src/os/windows/src/twintcpserver.c
rename to src/os/src/windows64/twintcpserver.c
diff --git a/src/os/windows/src/twintime.c b/src/os/src/windows64/twintime.c
similarity index 100%
rename from src/os/windows/src/twintime.c
rename to src/os/src/windows64/twintime.c
diff --git a/src/os/windows/src/twintimer.c b/src/os/src/windows64/twintimer.c
similarity index 100%
rename from src/os/windows/src/twintimer.c
rename to src/os/src/windows64/twintimer.c
diff --git a/src/plugins/http/CMakeLists.txt b/src/plugins/http/CMakeLists.txt
index 27bcae943c..3280a37c94 100644
--- a/src/plugins/http/CMakeLists.txt
+++ b/src/plugins/http/CMakeLists.txt
@@ -3,6 +3,7 @@ PROJECT(TDengine)
 
 IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/client/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/query/inc)
@@ -10,7 +11,6 @@ IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/deps/zlib-1.2.11/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/deps/cJson/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/deps/lz4/inc)
-  INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
   INCLUDE_DIRECTORIES(inc)
   AUX_SOURCE_DIRECTORY(src SRC)
   ADD_LIBRARY(http ${SRC})
diff --git a/src/plugins/http/src/httpJson.c b/src/plugins/http/src/httpJson.c
index 82666826bc..4748f03b66 100644
--- a/src/plugins/http/src/httpJson.c
+++ b/src/plugins/http/src/httpJson.c
@@ -45,7 +45,7 @@ int httpWriteBufByFd(struct HttpContext* pContext, const char* buf, int sz) {
 
   do {
     if (pContext->fd > 2){
-      len = (int)send(pContext->fd, buf + writeLen, (size_t)(sz - writeLen), MSG_NOSIGNAL);
+      len = (int)taosSend(pContext->fd, buf + writeLen, (size_t)(sz - writeLen), MSG_NOSIGNAL);
     }
     else {
       return sz;
diff --git a/src/plugins/monitor/CMakeLists.txt b/src/plugins/monitor/CMakeLists.txt
index 0ea5507501..9a20286797 100644
--- a/src/plugins/monitor/CMakeLists.txt
+++ b/src/plugins/monitor/CMakeLists.txt
@@ -3,11 +3,11 @@ PROJECT(TDengine)
 
 IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/client/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/query/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/common/inc)
-  INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
   INCLUDE_DIRECTORIES(inc)
   AUX_SOURCE_DIRECTORY(./src SRC)
   ADD_LIBRARY(monitor ${SRC})
diff --git a/src/plugins/mqtt/CMakeLists.txt b/src/plugins/mqtt/CMakeLists.txt
index cc88bd95a4..5fc8f9039f 100644
--- a/src/plugins/mqtt/CMakeLists.txt
+++ b/src/plugins/mqtt/CMakeLists.txt
@@ -3,6 +3,7 @@ PROJECT(TDengine)
 
 IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/client/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/query/inc)
@@ -10,7 +11,6 @@ IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/deps/cJson/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/deps/MQTT-C/include)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/deps/MQTT-C/examples/templates)
-  INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
   INCLUDE_DIRECTORIES(inc)
   AUX_SOURCE_DIRECTORY(src SRC)
   ADD_LIBRARY(mqtt ${SRC})
diff --git a/src/query/CMakeLists.txt b/src/query/CMakeLists.txt
index 620fd217de..625b85d908 100644
--- a/src/query/CMakeLists.txt
+++ b/src/query/CMakeLists.txt
@@ -1,9 +1,9 @@
 CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
 PROJECT(TDengine)
 
-INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
-INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
+  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/common/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/tsdb/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/client/inc)
diff --git a/src/query/src/qTsbuf.c b/src/query/src/qTsbuf.c
index 20b29107f5..90cf394035 100644
--- a/src/query/src/qTsbuf.c
+++ b/src/query/src/qTsbuf.c
@@ -740,7 +740,7 @@ int32_t tsBufMerge(STSBuf* pDestBuf, const STSBuf* pSrcBuf, int32_t vnodeId) {
   int32_t size = pSrcBuf->fileSize - offset;
 
 #ifdef LINUX
-  ssize_t rc = tsendfile(fileno(pDestBuf->f), fileno(pSrcBuf->f), &offset, size);
+  ssize_t rc = taosTSendFile(fileno(pDestBuf->f), fileno(pSrcBuf->f), &offset, size);
 #else
   ssize_t rc = fsendfile(pDestBuf->f, pSrcBuf->f, &offset, size);
 #endif
diff --git a/src/rpc/CMakeLists.txt b/src/rpc/CMakeLists.txt
index 96c63b45ca..902c8b66e4 100644
--- a/src/rpc/CMakeLists.txt
+++ b/src/rpc/CMakeLists.txt
@@ -1,8 +1,8 @@
 CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
 PROJECT(TDengine)
 
-INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/common/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/deps/cJson/inc)
@@ -12,10 +12,11 @@ INCLUDE_DIRECTORIES(inc)
 IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
   AUX_SOURCE_DIRECTORY(./src SRC)
 ELSEIF (TD_DARWIN_64)
-  LIST(APPEND SRC ./src/thaship.c)
-  LIST(APPEND SRC ./src/trpc.c)
-  LIST(APPEND SRC ./src/tstring.c)
-  LIST(APPEND SRC ./src/tudp.c)
+  #LIST(APPEND SRC ./src/thaship.c)
+  #LIST(APPEND SRC ./src/trpc.c)
+  #LIST(APPEND SRC ./src/tstring.c)
+  #LIST(APPEND SRC ./src/tudp.c)
+  AUX_SOURCE_DIRECTORY(src SRC)
 ELSEIF (TD_WINDOWS_64)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/deps/pthread)
   LIST(APPEND SRC ./src/thaship.c)
diff --git a/src/rpc/src/rpcUdp.c b/src/rpc/src/rpcUdp.c
index decd7a8307..bdaae4c597 100644
--- a/src/rpc/src/rpcUdp.c
+++ b/src/rpc/src/rpcUdp.c
@@ -242,7 +242,7 @@ int taosSendUdpData(uint32_t ip, uint16_t port, void *data, int dataLen, void *c
   destAdd.sin_addr.s_addr = ip;
   destAdd.sin_port = htons(port);
 
-  int ret = (int)sendto(pConn->fd, data, (size_t)dataLen, 0, (struct sockaddr *)&destAdd, sizeof(destAdd));
+  int ret = (int)taosSendto(pConn->fd, data, (size_t)dataLen, 0, (struct sockaddr *)&destAdd, sizeof(destAdd));
 
   return ret;
 }
diff --git a/src/rpc/test/CMakeLists.txt b/src/rpc/test/CMakeLists.txt
index 6787de56f6..ac7ea8e4c1 100644
--- a/src/rpc/test/CMakeLists.txt
+++ b/src/rpc/test/CMakeLists.txt
@@ -1,13 +1,13 @@
 CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
 PROJECT(TDengine)
 
-IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
-  INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
-  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
-  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
-  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/common/inc)
-  INCLUDE_DIRECTORIES(../inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/common/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/rpc/inc)
 
+IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
   LIST(APPEND CLIENT_SRC ./rclient.c)
   ADD_EXECUTABLE(rclient ${CLIENT_SRC})
   TARGET_LINK_LIBRARIES(rclient trpc)
diff --git a/src/sync/CMakeLists.txt b/src/sync/CMakeLists.txt
index 0a5d18022b..ca6a74f695 100644
--- a/src/sync/CMakeLists.txt
+++ b/src/sync/CMakeLists.txt
@@ -2,8 +2,8 @@ CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
 PROJECT(TDengine)
 
 IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
-  INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/common/inc)
   INCLUDE_DIRECTORIES(${TD_ENTERPRISE_DIR}/src/inc)
diff --git a/src/sync/src/syncRetrieve.c b/src/sync/src/syncRetrieve.c
index c7f136ed9d..74970017fa 100644
--- a/src/sync/src/syncRetrieve.c
+++ b/src/sync/src/syncRetrieve.c
@@ -140,7 +140,7 @@ static int syncRetrieveFile(SSyncPeer *pPeer)
     int sfd = open(name, O_RDONLY);
     if ( sfd < 0 ) break;
 
-    ret = tsendfile(pPeer->syncFd, sfd, NULL, fileInfo.size); 
+    ret = taosTSendFile(pPeer->syncFd, sfd, NULL, fileInfo.size); 
     close(sfd); 
     if (ret <0) break;
 
@@ -393,7 +393,7 @@ static int syncRetrieveWal(SSyncPeer *pPeer)
     int sfd = open(fname, O_RDONLY);
     if (sfd < 0) break;
 
-    code = tsendfile(pPeer->syncFd, sfd, NULL, size); 
+    code = taosTSendFile(pPeer->syncFd, sfd, NULL, size); 
     close(sfd); 
     if (code <0) break;
 
diff --git a/src/sync/test/CMakeLists.txt b/src/sync/test/CMakeLists.txt
index fd8bdd1668..89d739080f 100644
--- a/src/sync/test/CMakeLists.txt
+++ b/src/sync/test/CMakeLists.txt
@@ -2,8 +2,8 @@ CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
 PROJECT(TDengine)
 
 IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
-  INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/common/inc)
   INCLUDE_DIRECTORIES(../inc)
diff --git a/src/tsdb/CMakeLists.txt b/src/tsdb/CMakeLists.txt
index b2154969d6..450afe337b 100644
--- a/src/tsdb/CMakeLists.txt
+++ b/src/tsdb/CMakeLists.txt
@@ -2,8 +2,8 @@ CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
 PROJECT(TDengine)
 
 IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
-  INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/common/inc)
   # INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/vnode/common/inc)
diff --git a/src/tsdb/src/tsdbFile.c b/src/tsdb/src/tsdbFile.c
index f698878698..6e7b39830e 100644
--- a/src/tsdb/src/tsdbFile.c
+++ b/src/tsdb/src/tsdbFile.c
@@ -12,23 +12,14 @@
  * 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 <dirent.h>
-#include <fcntl.h>
-#include <stdint.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <unistd.h>
-#include <libgen.h>
+#define _DEFAULT_SOURCE
+#include "os.h"
 
 #include "talgo.h"
 #include "tchecksum.h"
 #include "tsdbMain.h"
 #include "tutil.h"
 #include "ttime.h"
-#include "tfile.h"
 
 #ifdef TSDB_IDX
 const char *tsdbFileSuffix[] = {".idx", ".head", ".data", ".last", "", ".i", ".h", ".l"};
@@ -317,7 +308,7 @@ int tsdbUpdateFileHeader(SFile *pFile, uint32_t version) {
     terrno = TAOS_SYSTEM_ERROR(errno);
     return -1;
   }
-  if (twrite(pFile->fd, (void *)buf, TSDB_FILE_HEAD_SIZE) < TSDB_FILE_HEAD_SIZE) {
+  if (taosTWrite(pFile->fd, (void *)buf, TSDB_FILE_HEAD_SIZE) < TSDB_FILE_HEAD_SIZE) {
     tsdbError("failed to write %d bytes to file %s since %s", TSDB_FILE_HEAD_SIZE, pFile->fname, strerror(errno));
     terrno = TAOS_SYSTEM_ERROR(errno);
     return -1;
@@ -383,7 +374,7 @@ static int tsdbInitFile(SFile *pFile, STsdbRepo *pRepo, int fid, int type) {
   pFile->fd = -1;
   if (tsdbOpenFile(pFile, O_RDONLY) < 0) goto _err;
 
-  if (tread(pFile->fd, buf, TSDB_FILE_HEAD_SIZE) < TSDB_FILE_HEAD_SIZE) {
+  if (taosTRead(pFile->fd, buf, TSDB_FILE_HEAD_SIZE) < TSDB_FILE_HEAD_SIZE) {
     tsdbError("vgId:%d failed to read %d bytes from file %s since %s", REPO_ID(pRepo), TSDB_FILE_HEAD_SIZE,
               pFile->fname, strerror(errno));
     terrno = TAOS_SYSTEM_ERROR(errno);
diff --git a/src/tsdb/src/tsdbMain.c b/src/tsdb/src/tsdbMain.c
index 89a19c15af..3a453249a9 100644
--- a/src/tsdb/src/tsdbMain.c
+++ b/src/tsdb/src/tsdbMain.c
@@ -545,7 +545,7 @@ static int32_t tsdbSaveConfig(char *rootDir, STsdbCfg *pCfg) {
 
   taosCalcChecksumAppend(0, (uint8_t *)buf, TSDB_FILE_HEAD_SIZE);
 
-  if (twrite(fd, (void *)buf, TSDB_FILE_HEAD_SIZE) < TSDB_FILE_HEAD_SIZE) {
+  if (taosTWrite(fd, (void *)buf, TSDB_FILE_HEAD_SIZE) < TSDB_FILE_HEAD_SIZE) {
     tsdbError("vgId:%d failed to write %d bytes to file %s since %s", pCfg->tsdbId, TSDB_FILE_HEAD_SIZE, fname,
               strerror(errno));
     terrno = TAOS_SYSTEM_ERROR(errno);
@@ -586,7 +586,7 @@ static int tsdbLoadConfig(char *rootDir, STsdbCfg *pCfg) {
     goto _err;
   }
 
-  if (tread(fd, (void *)buf, TSDB_FILE_HEAD_SIZE) < TSDB_FILE_HEAD_SIZE) {
+  if (taosTRead(fd, (void *)buf, TSDB_FILE_HEAD_SIZE) < TSDB_FILE_HEAD_SIZE) {
     tsdbError("failed to read %d bytes from file %s since %s", TSDB_FILE_HEAD_SIZE, fname, strerror(errno));
     terrno = TAOS_SYSTEM_ERROR(errno);
     goto _err;
diff --git a/src/tsdb/src/tsdbRWHelper.c b/src/tsdb/src/tsdbRWHelper.c
index 28f2974573..9456996071 100644
--- a/src/tsdb/src/tsdbRWHelper.c
+++ b/src/tsdb/src/tsdbRWHelper.c
@@ -13,13 +13,13 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
+#define _DEFAULT_SOURCE
 #include "os.h"
 #include "talgo.h"
 #include "tchecksum.h"
 #include "tcoding.h"
 #include "tscompression.h"
 #include "tsdbMain.h"
-#include "tfile.h"
 
 #define TSDB_GET_COMPCOL_LEN(nCols) (sizeof(SCompData) + sizeof(SCompCol) * (nCols) + sizeof(TSCKSUM))
 #define TSDB_KEY_COL_OFFSET 0
@@ -379,7 +379,7 @@ int tsdbMoveLastBlockIfNeccessary(SRWHelper *pHelper) {
         return -1;
       }
 
-      if (tsendfile(helperNewLastF(pHelper)->fd, helperLastF(pHelper)->fd, NULL, pCompBlock->len) < pCompBlock->len) {
+      if (taosTSendFile(helperNewLastF(pHelper)->fd, helperLastF(pHelper)->fd, NULL, pCompBlock->len) < pCompBlock->len) {
         tsdbError("vgId:%d failed to sendfile from file %s to file %s since %s", REPO_ID(pHelper->pRepo),
                   helperLastF(pHelper)->fname, helperNewLastF(pHelper)->fname, strerror(errno));
         terrno = TAOS_SYSTEM_ERROR(errno);
@@ -424,7 +424,7 @@ int tsdbWriteCompInfo(SRWHelper *pHelper) {
     pIdx->tid = pHelper->tableInfo.tid;
     ASSERT(pIdx->offset >= TSDB_FILE_HEAD_SIZE);
 
-    if (twrite(pFile->fd, (void *)(pHelper->pCompInfo), pIdx->len) < pIdx->len) {
+    if (taosTWrite(pFile->fd, (void *)(pHelper->pCompInfo), pIdx->len) < pIdx->len) {
       tsdbError("vgId:%d failed to write %d bytes to file %s since %s", REPO_ID(pHelper->pRepo), pIdx->len,
                 pFile->fname, strerror(errno));
       terrno = TAOS_SYSTEM_ERROR(errno);
@@ -481,7 +481,7 @@ int tsdbWriteCompIdx(SRWHelper *pHelper) {
 
   pFile->info.offset = offset;
 
-  if (twrite(pFile->fd, (void *)pHelper->pWIdx, pFile->info.len) < pFile->info.len) {
+  if (taosTWrite(pFile->fd, (void *)pHelper->pWIdx, pFile->info.len) < pFile->info.len) {
     tsdbError("vgId:%d failed to write %d bytes to file %s since %s", REPO_ID(pHelper->pRepo), pFile->info.len,
               pFile->fname, strerror(errno));
     terrno = TAOS_SYSTEM_ERROR(errno);
@@ -514,7 +514,7 @@ int tsdbLoadCompIdx(SRWHelper *pHelper, void *target) {
         return -1;
       }
 
-      if (tread(fd, (void *)(pHelper->pBuffer), pFile->info.len) < pFile->info.len) {
+      if (taosTRead(fd, (void *)(pHelper->pBuffer), pFile->info.len) < pFile->info.len) {
         tsdbError("vgId:%d failed to read %d bytes from file %s since %s", REPO_ID(pHelper->pRepo), pFile->info.len,
                   pFile->fname, strerror(errno));
         terrno = TAOS_SYSTEM_ERROR(errno);
@@ -585,7 +585,7 @@ int tsdbLoadCompInfo(SRWHelper *pHelper, void *target) {
       }
 
       pHelper->pCompInfo = trealloc((void *)pHelper->pCompInfo, pIdx->len);
-      if (tread(fd, (void *)(pHelper->pCompInfo), pIdx->len) < pIdx->len) {
+      if (taosTRead(fd, (void *)(pHelper->pCompInfo), pIdx->len) < pIdx->len) {
         tsdbError("vgId:%d failed to read %d bytes from file %s since %s", REPO_ID(pHelper->pRepo), pIdx->len,
                   helperHeadF(pHelper)->fname, strerror(errno));
         terrno = TAOS_SYSTEM_ERROR(errno);
@@ -626,7 +626,7 @@ int tsdbLoadCompData(SRWHelper *pHelper, SCompBlock *pCompBlock, void *target) {
     return -1;
   }
 
-  if (tread(pFile->fd, (void *)pHelper->pCompData, tsize) < tsize) {
+  if (taosTRead(pFile->fd, (void *)pHelper->pCompData, tsize) < tsize) {
     tsdbError("vgId:%d failed to read %zu bytes from file %s since %s", REPO_ID(pHelper->pRepo), tsize, pFile->fname,
               strerror(errno));
     terrno = TAOS_SYSTEM_ERROR(errno);
@@ -841,7 +841,7 @@ static int tsdbWriteBlockToFile(SRWHelper *pHelper, SFile *pFile, SDataCols *pDa
                                        sizeof(TSCKSUM));
 
   // Write the whole block to file
-  if (twrite(pFile->fd, (void *)pCompData, lsize) < lsize) {
+  if (taosTWrite(pFile->fd, (void *)pCompData, lsize) < lsize) {
     tsdbError("vgId:%d failed to write %d bytes to file %s since %s", REPO_ID(helperRepo(pHelper)), lsize, pFile->fname,
               strerror(errno));
     terrno = TAOS_SYSTEM_ERROR(errno);
@@ -1222,7 +1222,7 @@ static int tsdbLoadColData(SRWHelper *pHelper, SFile *pFile, SCompBlock *pCompBl
     return -1;
   }
 
-  if (tread(pFile->fd, pHelper->pBuffer, pCompCol->len) < pCompCol->len) {
+  if (taosTRead(pFile->fd, pHelper->pBuffer, pCompCol->len) < pCompCol->len) {
     tsdbError("vgId:%d failed to read %d bytes from file %s since %s", REPO_ID(pHelper->pRepo), pCompCol->len, pFile->fname,
               strerror(errno));
     terrno = TAOS_SYSTEM_ERROR(errno);
@@ -1337,7 +1337,7 @@ static int tsdbLoadBlockDataImpl(SRWHelper *pHelper, SCompBlock *pCompBlock, SDa
     terrno = TAOS_SYSTEM_ERROR(errno);
     goto _err;
   }
-  if (tread(fd, (void *)pCompData, pCompBlock->len) < pCompBlock->len) {
+  if (taosTRead(fd, (void *)pCompData, pCompBlock->len) < pCompBlock->len) {
     tsdbError("vgId:%d failed to read %d bytes from file %s since %s", REPO_ID(pHelper->pRepo), pCompBlock->len,
               pFile->fname, strerror(errno));
     terrno = TAOS_SYSTEM_ERROR(errno);
diff --git a/src/util/CMakeLists.txt b/src/util/CMakeLists.txt
index d4350fc8b2..1969b40443 100644
--- a/src/util/CMakeLists.txt
+++ b/src/util/CMakeLists.txt
@@ -1,8 +1,8 @@
 CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
 PROJECT(TDengine)
 
-INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/common/inc)
 
@@ -11,7 +11,7 @@ IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/deps/lz4/inc)
   AUX_SOURCE_DIRECTORY(src SRC)
   ADD_LIBRARY(tutil ${SRC})
-  TARGET_LINK_LIBRARIES(tutil pthread os m rt lz4)
+  TARGET_LINK_LIBRARIES(tutil pthread osdetail m rt lz4)
   FIND_PATH(ICONV_INCLUDE_EXIST iconv.h /usr/include/ /usr/local/include/)
   IF (ICONV_INCLUDE_EXIST)
     ADD_DEFINITIONS(-DUSE_LIBICONV)
@@ -68,44 +68,12 @@ ELSEIF (TD_WINDOWS_64)
   LIST(APPEND SRC ./src/tutil.c)
   LIST(APPEND SRC ./src/version.c)
   ADD_LIBRARY(tutil ${SRC}) 
-  TARGET_LINK_LIBRARIES(tutil iconv regex pthread os winmm IPHLPAPI ws2_32 lz4)
+  TARGET_LINK_LIBRARIES(tutil iconv regex pthread osdetail winmm IPHLPAPI ws2_32 lz4)
 ELSEIF(TD_DARWIN_64)
   ADD_DEFINITIONS(-DUSE_LIBICONV)
-  LIST(APPEND SRC ./src/hash.c)
-  LIST(APPEND SRC ./src/ihash.c)
-  LIST(APPEND SRC ./src/lz4.c)
-  LIST(APPEND SRC ./src/shash.c)
-  LIST(APPEND SRC ./src/tbase64.c)
-  LIST(APPEND SRC ./src/tcache.c)
-  LIST(APPEND SRC ./src/tcompression.c)
-  LIST(APPEND SRC ./src/textbuffer.c)
-  LIST(APPEND SRC ./src/tglobalcfg.c)
-  LIST(APPEND SRC ./src/thash.c)
-  LIST(APPEND SRC ./src/thashutil.c)
-  LIST(APPEND SRC ./src/thistogram.c)
-  LIST(APPEND SRC ./src/tidpool.c)
-  LIST(APPEND SRC ./src/tinterpolation.c)
-  LIST(APPEND SRC ./src/tlog.c)
-  LIST(APPEND SRC ./src/tlosertree.c)
-  LIST(APPEND SRC ./src/tmd5.c)
-  LIST(APPEND SRC ./src/tmem.c)
-  LIST(APPEND SRC ./src/tmempool.c)
-  LIST(APPEND SRC ./src/tmodule.c)
-  LIST(APPEND SRC ./src/tnote.c)
-  LIST(APPEND SRC ./src/tpercentile.c)
-  LIST(APPEND SRC ./src/tsched.c)
-  LIST(APPEND SRC ./src/tskiplist.c)
-  LIST(APPEND SRC ./src/tsocket.c)
-  LIST(APPEND SRC ./src/tstrbuild.c)
-  LIST(APPEND SRC ./src/ttime.c)
-  LIST(APPEND SRC ./src/ttimer.c)
-  LIST(APPEND SRC ./src/ttokenizer.c)
-  LIST(APPEND SRC ./src/ttypes.c)
-  LIST(APPEND SRC ./src/tutil.c)
-  LIST(APPEND SRC ./src/version.c)
-  LIST(APPEND SRC ./src/hash.c)
+  AUX_SOURCE_DIRECTORY(src SRC)
   ADD_LIBRARY(tutil ${SRC})
-  TARGET_LINK_LIBRARIES(tutil iconv pthread os lz4)
+  TARGET_LINK_LIBRARIES(tutil iconv pthread osdetail lz4)
 ENDIF()
 
 #  TARGET_LINK_LIBRARIES(tutil mstorage)
diff --git a/src/util/inc/talgo.h b/src/util/inc/talgo.h
index e71e340a21..5de8a302b1 100644
--- a/src/util/inc/talgo.h
+++ b/src/util/inc/talgo.h
@@ -20,6 +20,8 @@
 extern "C" {
 #endif
 
+#include "os.h"
+
 #define TD_EQ 0x1
 #define TD_GT 0x2
 #define TD_LT 0x4
diff --git a/src/util/inc/tfile.h b/src/util/inc/tfile.h
deleted file mode 100644
index de52a40967..0000000000
--- a/src/util/inc/tfile.h
+++ /dev/null
@@ -1,33 +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/>.
- */
-
-#ifndef TDENGINE_TFILE_H
-#define TDENGINE_TFILE_H
-
-#ifdef TAOS_RANDOM_FILE_FAIL
-
-void taosSetRandomFileFailFactor(int factor);
-void taosSetRandomFileFailOutput(const char *path);
-ssize_t taos_tread(int fd, void *buf, size_t count, const char *file, uint32_t line);
-ssize_t taos_twrite(int fd, void *buf, size_t count, const char *file, uint32_t line);
-off_t taos_lseek(int fd, off_t offset, int whence, const char *file, uint32_t line);
-
-#define tread(fd, buf, count)  taos_tread(fd, buf, count, __FILE__, __LINE__)
-#define twrite(fd, buf, count)  taos_twrite(fd, buf, count, __FILE__, __LINE__)
-#define lseek(fd, offset, whence)  taos_lseek(fd, offset, whence, __FILE__, __LINE__)
-
-#endif  // TAOS_RANDOM_FILE_FAIL
-
-#endif  // TDENGINE_TFILE_H
diff --git a/src/util/inc/tutil.h b/src/util/inc/tutil.h
index 34f35c3807..4c003eeb2c 100644
--- a/src/util/inc/tutil.h
+++ b/src/util/inc/tutil.h
@@ -143,8 +143,6 @@ char *strbetween(char *string, char *begin, char *end);
 
 char *paGetToken(char *src, char **token, int32_t *tokenLen);
 
-void taosMsleep(int32_t mseconds);
-
 int32_t taosByteArrayToHexStr(char bytes[], int32_t len, char hexstr[]);
 
 int32_t taosHexStrToByteArray(char hexstr[], char bytes[]);
@@ -225,6 +223,9 @@ ssize_t taos_getline(char **lineptr, size_t *n, FILE *stream, const char *file,
 
 #endif // TAOS_MEM_CHECK
 
+
+char *taosCharsetReplace(char *charsetstr);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/util/src/tbuffer.c b/src/util/src/tbuffer.c
index 4b37cbd2d5..4af435798c 100644
--- a/src/util/src/tbuffer.c
+++ b/src/util/src/tbuffer.c
@@ -13,6 +13,7 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "os.h"
 #include <stdlib.h>
 #include <memory.h>
 #include <assert.h>
diff --git a/src/util/src/tcache.c b/src/util/src/tcache.c
index 92d4b2caac..3d2df5f214 100644
--- a/src/util/src/tcache.c
+++ b/src/util/src/tcache.c
@@ -259,7 +259,7 @@ SCacheObj *taosCacheInit(int32_t keyType, int64_t refreshTimeInSeconds, bool ext
     return NULL;
   }
 
-  pthread_attr_t thattr = {{0}};
+  pthread_attr_t thattr;
   pthread_attr_init(&thattr);
   pthread_attr_setdetachstate(&thattr, PTHREAD_CREATE_JOINABLE);
 
@@ -288,7 +288,7 @@ void *taosCachePut(SCacheObj *pCacheObj, const void *key, size_t keyLen, const v
       uDebug("cache:%s, key:%p, %p added into cache, added:%" PRIu64 ", expire:%" PRIu64 ", totalNum:%d totalSize:%" PRId64
              "bytes size:%" PRId64 "bytes",
              pCacheObj->name, key, pNode->data, pNode->addedTime, pNode->expireTime,
-             (int32_t)taosHashGetSize(pCacheObj->pHashTable), pCacheObj->totalSize, dataSize);
+             (int32_t)taosHashGetSize(pCacheObj->pHashTable), pCacheObj->totalSize, (int64_t)dataSize);
     } else {
       uError("cache:%s, key:%p, failed to added into cache, out of memory", pCacheObj->name, key);
     }
diff --git a/src/util/src/tkvstore.c b/src/util/src/tkvstore.c
index 0704285da5..d7bf9d7857 100644
--- a/src/util/src/tkvstore.c
+++ b/src/util/src/tkvstore.c
@@ -12,22 +12,15 @@
  * 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 <errno.h>
-#include <fcntl.h>
-#include <libgen.h>
-#include <string.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <unistd.h>
 
-#include "hash.h"
+#define _DEFAULT_SOURCE
 #include "os.h"
+#include "hash.h"
 #include "taoserror.h"
 #include "tchecksum.h"
 #include "tcoding.h"
 #include "tkvstore.h"
 #include "tulog.h"
-#include "tfile.h"
 
 #define TD_KVSTORE_HEADER_SIZE 512
 #define TD_KVSTORE_MAJOR_VERSION 1
@@ -182,7 +175,7 @@ int tdKVStoreStartCommit(SKVStore *pStore) {
     goto _err;
   }
 
-  if (tsendfile(pStore->sfd, pStore->fd, NULL, TD_KVSTORE_HEADER_SIZE) < TD_KVSTORE_HEADER_SIZE) {
+  if (taosTSendFile(pStore->sfd, pStore->fd, NULL, TD_KVSTORE_HEADER_SIZE) < TD_KVSTORE_HEADER_SIZE) {
     uError("failed to send file %d bytes since %s", TD_KVSTORE_HEADER_SIZE, strerror(errno));
     terrno = TAOS_SYSTEM_ERROR(errno);
     goto _err;
@@ -242,13 +235,13 @@ int tdUpdateKVStoreRecord(SKVStore *pStore, uint64_t uid, void *cont, int contLe
   ASSERT(tlen == POINTER_DISTANCE(pBuf, buf));
   ASSERT(tlen == sizeof(SKVRecord));
 
-  if (twrite(pStore->fd, buf, tlen) < tlen) {
+  if (taosTWrite(pStore->fd, buf, tlen) < tlen) {
     uError("failed to write %d bytes to file %s since %s", tlen, pStore->fname, strerror(errno));
     terrno = TAOS_SYSTEM_ERROR(errno);
     return -1;
   }
 
-  if (twrite(pStore->fd, cont, contLen) < contLen) {
+  if (taosTWrite(pStore->fd, cont, contLen) < contLen) {
     uError("failed to write %d bytes to file %s since %s", contLen, pStore->fname, strerror(errno));
     return -1;
   }
@@ -286,8 +279,8 @@ int tdDropKVStoreRecord(SKVStore *pStore, uint64_t uid) {
   void *pBuf = buf;
   tdEncodeKVRecord(&pBuf, &rInfo);
 
-  if (twrite(pStore->fd, buf, POINTER_DISTANCE(pBuf, buf)) < POINTER_DISTANCE(pBuf, buf)) {
-    uError("failed to write %" PRId64 " bytes to file %s since %s", POINTER_DISTANCE(pBuf, buf), pStore->fname, strerror(errno));
+  if (taosTWrite(pStore->fd, buf, POINTER_DISTANCE(pBuf, buf)) < POINTER_DISTANCE(pBuf, buf)) {
+    uError("failed to write %" PRId64 " bytes to file %s since %s", (int64_t)(POINTER_DISTANCE(pBuf, buf)), pStore->fname, strerror(errno));
     terrno = TAOS_SYSTEM_ERROR(errno);
     return -1;
   }
@@ -335,7 +328,7 @@ static int tdLoadKVStoreHeader(int fd, char *fname, SStoreInfo *pInfo) {
     return -1;
   }
 
-  if (tread(fd, buf, TD_KVSTORE_HEADER_SIZE) < TD_KVSTORE_HEADER_SIZE) {
+  if (taosTRead(fd, buf, TD_KVSTORE_HEADER_SIZE) < TD_KVSTORE_HEADER_SIZE) {
     uError("failed to read %d bytes from file %s since %s", TD_KVSTORE_HEADER_SIZE, fname, strerror(errno));
     terrno = TAOS_SYSTEM_ERROR(errno);
     return -1;
@@ -366,7 +359,7 @@ static int tdUpdateKVStoreHeader(int fd, char *fname, SStoreInfo *pInfo) {
   ASSERT(POINTER_DISTANCE(pBuf, buf) + sizeof(TSCKSUM) <= TD_KVSTORE_HEADER_SIZE);
 
   taosCalcChecksumAppend(0, (uint8_t *)buf, TD_KVSTORE_HEADER_SIZE);
-  if (twrite(fd, buf, TD_KVSTORE_HEADER_SIZE) < TD_KVSTORE_HEADER_SIZE) {
+  if (taosTWrite(fd, buf, TD_KVSTORE_HEADER_SIZE) < TD_KVSTORE_HEADER_SIZE) {
     uError("failed to write %d bytes to file %s since %s", TD_KVSTORE_HEADER_SIZE, fname, strerror(errno));
     terrno = TAOS_SYSTEM_ERROR(errno);
     return -1;
@@ -499,7 +492,7 @@ static int tdRestoreKVStore(SKVStore *pStore) {
   ASSERT(pStore->info.size == TD_KVSTORE_HEADER_SIZE);
 
   while (true) {
-    ssize_t tsize = tread(pStore->fd, tbuf, sizeof(SKVRecord));
+    ssize_t tsize = taosTRead(pStore->fd, tbuf, sizeof(SKVRecord));
     if (tsize == 0) break;
     if (tsize < sizeof(SKVRecord)) {
       uError("failed to read %zu bytes from file %s at offset %" PRId64 "since %s", sizeof(SKVRecord), pStore->fname,
@@ -562,7 +555,7 @@ static int tdRestoreKVStore(SKVStore *pStore) {
       goto _err;
     }
 
-    if (tread(pStore->fd, buf, pRecord->size) < pRecord->size) {
+    if (taosTRead(pStore->fd, buf, pRecord->size) < pRecord->size) {
       uError("failed to read %" PRId64 " bytes from file %s since %s, offset %" PRId64, pRecord->size, pStore->fname,
              strerror(errno), pRecord->offset);
       terrno = TAOS_SYSTEM_ERROR(errno);
diff --git a/src/util/src/tlog.c b/src/util/src/tlog.c
index c2c56f29db..2489ae56be 100644
--- a/src/util/src/tlog.c
+++ b/src/util/src/tlog.c
@@ -301,11 +301,11 @@ static int32_t taosOpenLogFile(char *fn, int32_t maxLines, int32_t maxFileNum) {
   lseek(tsLogObj.logHandle->fd, 0, SEEK_END);
 
   sprintf(name, "==================================================\n");
-  twrite(tsLogObj.logHandle->fd, name, (uint32_t)strlen(name));
+  taosTWrite(tsLogObj.logHandle->fd, name, (uint32_t)strlen(name));
   sprintf(name, "                new log file                      \n");
-  twrite(tsLogObj.logHandle->fd, name, (uint32_t)strlen(name));
+  taosTWrite(tsLogObj.logHandle->fd, name, (uint32_t)strlen(name));
   sprintf(name, "==================================================\n");
-  twrite(tsLogObj.logHandle->fd, name, (uint32_t)strlen(name));
+  taosTWrite(tsLogObj.logHandle->fd, name, (uint32_t)strlen(name));
 
   return 0;
 }
@@ -355,7 +355,7 @@ void taosPrintLog(const char *flags, int32_t dflag, const char *format, ...) {
     if (tsAsyncLog) {
       taosPushLogBuffer(tsLogObj.logHandle, buffer, len);
     } else {
-      twrite(tsLogObj.logHandle->fd, buffer, len);
+      taosTWrite(tsLogObj.logHandle->fd, buffer, len);
     }
 
     if (tsLogObj.maxLines > 0) {
@@ -365,7 +365,7 @@ void taosPrintLog(const char *flags, int32_t dflag, const char *format, ...) {
     }
   }
 
-  if (dflag & DEBUG_SCREEN) twrite(1, buffer, (uint32_t)len);
+  if (dflag & DEBUG_SCREEN) taosTWrite(1, buffer, (uint32_t)len);
 }
 
 void taosDumpData(unsigned char *msg, int32_t len) {
@@ -384,7 +384,7 @@ void taosDumpData(unsigned char *msg, int32_t len) {
     pos += 3;
     if (c >= 16) {
       temp[pos++] = '\n';
-      twrite(tsLogObj.logHandle->fd, temp, (uint32_t)pos);
+      taosTWrite(tsLogObj.logHandle->fd, temp, (uint32_t)pos);
       c = 0;
       pos = 0;
     }
@@ -392,7 +392,7 @@ void taosDumpData(unsigned char *msg, int32_t len) {
 
   temp[pos++] = '\n';
 
-  twrite(tsLogObj.logHandle->fd, temp, (uint32_t)pos);
+  taosTWrite(tsLogObj.logHandle->fd, temp, (uint32_t)pos);
 
   return;
 }
@@ -432,7 +432,7 @@ void taosPrintLongString(const char *flags, int32_t dflag, const char *format, .
     if (tsAsyncLog) {
       taosPushLogBuffer(tsLogObj.logHandle, buffer, len);
     } else {
-      twrite(tsLogObj.logHandle->fd, buffer, len);
+      taosTWrite(tsLogObj.logHandle->fd, buffer, len);
     }
     
     if (tsLogObj.maxLines > 0) {
@@ -442,7 +442,7 @@ void taosPrintLongString(const char *flags, int32_t dflag, const char *format, .
     }
   }
 
-  if (dflag & DEBUG_SCREEN) twrite(1, buffer, (uint32_t)len);
+  if (dflag & DEBUG_SCREEN) taosTWrite(1, buffer, (uint32_t)len);
 }
 
 #if 0
@@ -571,7 +571,7 @@ static void *taosAsyncOutputLog(void *param) {
     while (1) {
       log_size = taosPollLogBuffer(tLogBuff, tempBuffer, TSDB_DEFAULT_LOG_BUF_UNIT);
       if (log_size) {
-        twrite(tLogBuff->fd, tempBuffer, log_size);
+        taosTWrite(tLogBuff->fd, tempBuffer, log_size);
         LOG_BUF_START(tLogBuff) = (LOG_BUF_START(tLogBuff) + log_size) % LOG_BUF_SIZE(tLogBuff);
       } else {
         break;
diff --git a/src/util/src/tnote.c b/src/util/src/tnote.c
index 12a7fc2b9b..fdf11eb5c4 100644
--- a/src/util/src/tnote.c
+++ b/src/util/src/tnote.c
@@ -264,7 +264,7 @@ void taosNotePrint(taosNoteInfo * pNote, const char * const format, ...)
     buffer[len] = 0;
 
     if (pNote->taosNoteFd >= 0)  {
-        twrite(pNote->taosNoteFd, buffer, (unsigned int)len);
+        taosTWrite(pNote->taosNoteFd, buffer, (unsigned int)len);
 
         if (pNote->taosNoteMaxLines > 0) {
             pNote->taosNoteLines++;
diff --git a/src/util/src/tsocket.c b/src/util/src/tsocket.c
index 5de61a3d57..6c536a4303 100644
--- a/src/util/src/tsocket.c
+++ b/src/util/src/tsocket.c
@@ -164,7 +164,7 @@ int taosNonblockwrite(int fd, char *ptr, int nbytes) {
       return -1;
     }
 
-    nwritten = (int)send(fd, ptr, (size_t)nleft, MSG_NOSIGNAL);
+    nwritten = (int)taosSend(fd, ptr, (size_t)nleft, MSG_NOSIGNAL);
     if (nwritten <= 0) {
       if (errno == EAGAIN || errno == EINTR) continue;
 
diff --git a/src/vnode/CMakeLists.txt b/src/vnode/CMakeLists.txt
index a1c56b32b5..9b6b03209e 100644
--- a/src/vnode/CMakeLists.txt
+++ b/src/vnode/CMakeLists.txt
@@ -2,8 +2,8 @@ CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
 PROJECT(TDengine)
 
 IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
-  INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/query/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/tsdb/inc)
diff --git a/src/vnode/src/vnodeMain.c b/src/vnode/src/vnodeMain.c
index dd5ec18439..77d4503d9d 100644
--- a/src/vnode/src/vnodeMain.c
+++ b/src/vnode/src/vnodeMain.c
@@ -46,15 +46,6 @@ static int      vnodeGetWalInfo(void *ahandle, char *name, uint32_t *index);
 static void     vnodeNotifyRole(void *ahandle, int8_t role);
 static int      vnodeNotifyFileSynced(void *ahandle, uint64_t fversion);
 
-#ifndef _SYNC
-tsync_h syncStart(const SSyncInfo *info) { return NULL; }
-int32_t syncForwardToPeer(tsync_h shandle, void *pHead, void *mhandle, int qtype) { return 0; }
-void    syncStop(tsync_h shandle) {}
-int32_t syncReconfig(tsync_h shandle, const SSyncCfg * cfg) { return 0; }
-int     syncGetNodesRole(tsync_h shandle, SNodesRole * cfg) { return 0; }
-void    syncConfirmForward(tsync_h shandle, uint64_t version, int32_t code) {}
-#endif
-
 int32_t vnodeInitResources() {
   vnodeInitWriteFp();
   vnodeInitReadFp();
@@ -289,14 +280,10 @@ int32_t vnodeOpen(int32_t vnode, char *rootDir) {
   syncInfo.notifyFileSynced = vnodeNotifyFileSynced;
   pVnode->sync = syncStart(&syncInfo);
 
-#ifndef _SYNC
-  pVnode->role = TAOS_SYNC_ROLE_MASTER;
-#else
   if (pVnode->sync == NULL) {
     vnodeCleanUp(pVnode);
     return terrno;
   }
-#endif
 
   pVnode->qMgmt = qOpenQueryMgmt(pVnode->vgId);
   pVnode->events = NULL;
diff --git a/src/wal/CMakeLists.txt b/src/wal/CMakeLists.txt
index 684616ba0e..a9c20f643a 100644
--- a/src/wal/CMakeLists.txt
+++ b/src/wal/CMakeLists.txt
@@ -1,9 +1,9 @@
 CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
 PROJECT(TDengine)
 
-INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
-INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
+  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
 INCLUDE_DIRECTORIES(inc)
 
 AUX_SOURCE_DIRECTORY(${CMAKE_CURRENT_SOURCE_DIR}/src SRC)
diff --git a/src/wal/src/walMain.c b/src/wal/src/walMain.c
index a0e2ccb51d..43869da477 100644
--- a/src/wal/src/walMain.c
+++ b/src/wal/src/walMain.c
@@ -13,14 +13,7 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include <stdint.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <sys/types.h>
-#include <dirent.h>
-#include <unistd.h>
-#include <fcntl.h> 
-
+#define _DEFAULT_SOURCE
 #include "os.h"
 #include "tlog.h"
 #include "tchecksum.h"
@@ -29,7 +22,6 @@
 #include "taoserror.h"
 #include "twal.h"
 #include "tqueue.h"
-#include "tfile.h"
 
 #define walPrefix "wal"
 
@@ -214,7 +206,7 @@ int walWrite(void *handle, SWalHead *pHead) {
   taosCalcChecksumAppend(0, (uint8_t *)pHead, sizeof(SWalHead));
   int contLen = pHead->len + sizeof(SWalHead);
 
-  if(twrite(pWal->fd, pHead, contLen) != contLen) {
+  if(taosTWrite(pWal->fd, pHead, contLen) != contLen) {
     wError("wal:%s, failed to write(%s)", pWal->name, strerror(errno));
     terrno = TAOS_SYSTEM_ERROR(errno);
   } else {
@@ -373,7 +365,7 @@ static int walRestoreWalFile(SWal *pWal, void *pVnode, FWalWrite writeFp) {
   wDebug("wal:%s, start to restore", name);
 
   while (1) {
-    int ret = tread(fd, pHead, sizeof(SWalHead));
+    int ret = taosTRead(fd, pHead, sizeof(SWalHead));
     if ( ret == 0)  break;  
 
     if (ret != sizeof(SWalHead)) {
@@ -388,7 +380,7 @@ static int walRestoreWalFile(SWal *pWal, void *pVnode, FWalWrite writeFp) {
       break;
     } 
 
-    ret = tread(fd, pHead->cont, pHead->len);
+    ret = taosTRead(fd, pHead->cont, pHead->len);
     if ( ret != pHead->len) {
       wWarn("wal:%s, failed to read body, skip, len:%d ret:%d", name, pHead->len, ret);
       terrno = TAOS_SYSTEM_ERROR(errno);
diff --git a/src/wal/test/CMakeLists.txt b/src/wal/test/CMakeLists.txt
index f007bc3882..be0b8a948d 100644
--- a/src/wal/test/CMakeLists.txt
+++ b/src/wal/test/CMakeLists.txt
@@ -2,8 +2,8 @@ CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
 PROJECT(TDengine)
 
 IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
-  INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/common/inc)
   INCLUDE_DIRECTORIES(../inc)
diff --git a/tests/test/c/CMakeLists.txt b/tests/test/c/CMakeLists.txt
index 8686a23f65..4736c1ebed 100644
--- a/tests/test/c/CMakeLists.txt
+++ b/tests/test/c/CMakeLists.txt
@@ -2,9 +2,9 @@ CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
 PROJECT(TDengine)
 
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/common/inc)
-INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
 
 IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
   #add_executable(insertPerTable insertPerTable.c)
diff --git a/tests/tsim/CMakeLists.txt b/tests/tsim/CMakeLists.txt
index 14ef791a4e..0a11a8f14e 100644
--- a/tests/tsim/CMakeLists.txt
+++ b/tests/tsim/CMakeLists.txt
@@ -1,11 +1,11 @@
 PROJECT(TDengine)
 
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/os/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/common/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/client/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/deps/cJson/inc)
-INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
 INCLUDE_DIRECTORIES(inc)
 
 IF (TD_WINDOWS_64)