diff --git a/source/dnode/mgmt/node_mgmt/src/dmTransport.c b/source/dnode/mgmt/node_mgmt/src/dmTransport.c
index 20dbc2114d7e6145c2d84852f70c527e5e2aff20..f11378f84ce216af5c6e8a5f8e73bc4dc46290c0 100644
--- a/source/dnode/mgmt/node_mgmt/src/dmTransport.c
+++ b/source/dnode/mgmt/node_mgmt/src/dmTransport.c
@@ -111,7 +111,12 @@ static void dmProcessRpcMsg(SDnode *pDnode, SRpcMsg *pRpc, SEpSet *pEpSet) {
     dGError("msg:%p, type:%s pCont is NULL", pRpc, TMSG_INFO(pRpc->msgType));
     terrno = TSDB_CODE_INVALID_MSG_LEN;
     goto _OVER;
-  }
+  } /* else if ((pRpc->code == TSDB_CODE_RPC_NETWORK_UNAVAIL || pRpc->code == TSDB_CODE_RPC_BROKEN_LINK) &&
+              (!IsReq(pRpc)) && (pRpc->pCont == NULL)) {
+     dGError("msg:%p, type:%s pCont is NULL, err: %s", pRpc, TMSG_INFO(pRpc->msgType), tstrerror(pRpc->code));
+     terrno = pRpc->code;
+     goto _OVER;
+   }*/
 
   if (pHandle->defaultNtype == NODE_END) {
     dGError("msg:%p, type:%s not processed since no handle", pRpc, TMSG_INFO(pRpc->msgType));
diff --git a/source/libs/index/inc/indexFstFile.h b/source/libs/index/inc/indexFstFile.h
index 0ddffe7df0c0857b3c5c9ce2aaae856d708d2283..d15141f79af3112a55fa5fa09be1b8caa39f602e 100644
--- a/source/libs/index/inc/indexFstFile.h
+++ b/source/libs/index/inc/indexFstFile.h
@@ -44,6 +44,11 @@ typedef struct IFileCtx {
       bool      readOnly;
       char      buf[256];
       int64_t   size;
+
+      char*   wBuf;
+      int32_t wBufOffset;
+      int32_t wBufCap;
+
 #ifdef USE_MMAP
       char* ptr;
 #endif
diff --git a/source/libs/index/src/indexFstFile.c b/source/libs/index/src/indexFstFile.c
index 5538584754a92f8e11ef0deecbfb28aee12ef8a9..4620af8694e538a3525adaed11a1277ec14cd0a9 100644
--- a/source/libs/index/src/indexFstFile.c
+++ b/source/libs/index/src/indexFstFile.c
@@ -38,14 +38,41 @@ static FORCE_INLINE void idxGenLRUKey(char* buf, const char* path, int32_t block
   return;
 }
 static FORCE_INLINE int idxFileCtxDoWrite(IFileCtx* ctx, uint8_t* buf, int len) {
+  int tlen = len;
   if (ctx->type == TFILE) {
-    int nwr = taosWriteFile(ctx->file.pFile, buf, len);
-    assert(nwr == len);
+    int32_t cap = ctx->file.wBufCap;
+    if (len + ctx->file.wBufOffset >= cap) {
+      int32_t nw = cap - ctx->file.wBufOffset;
+      memcpy(ctx->file.wBuf + ctx->file.wBufOffset, buf, nw);
+      taosWriteFile(ctx->file.pFile, ctx->file.wBuf, cap);
+
+      memset(ctx->file.wBuf, 0, cap);
+      ctx->file.wBufOffset = 0;
+
+      len -= nw;
+      buf += nw;
+
+      nw = (len / cap) * cap;
+      if (nw != 0) {
+        taosWriteFile(ctx->file.pFile, buf, nw);
+      }
+
+      len -= nw;
+      buf += nw;
+      if (len != 0) {
+        memcpy(ctx->file.wBuf, buf, len);
+      }
+      ctx->file.wBufOffset += len;
+    } else {
+      memcpy(ctx->file.wBuf + ctx->file.wBufOffset, buf, len);
+      ctx->file.wBufOffset += len;
+    }
+
   } else {
     memcpy(ctx->mem.buf + ctx->offset, buf, len);
   }
-  ctx->offset += len;
-  return len;
+  ctx->offset += tlen;
+  return tlen;
 }
 static FORCE_INLINE int idxFileCtxDoRead(IFileCtx* ctx, uint8_t* buf, int len) {
   int nRead = 0;
@@ -127,14 +154,22 @@ static int idxFileCtxDoReadFrom(IFileCtx* ctx, uint8_t* buf, int len, int32_t of
 }
 static FORCE_INLINE int idxFileCtxGetSize(IFileCtx* ctx) {
   if (ctx->type == TFILE) {
-    int64_t file_size = 0;
-    taosStatFile(ctx->file.buf, &file_size, NULL);
-    return (int)file_size;
+    if (ctx->file.readOnly == false) {
+      return ctx->offset;
+    } else {
+      int64_t file_size = 0;
+      taosStatFile(ctx->file.buf, &file_size, NULL);
+      return (int)file_size;
+    }
   }
   return 0;
 }
 static FORCE_INLINE int idxFileCtxDoFlush(IFileCtx* ctx) {
   if (ctx->type == TFILE) {
+    if (ctx->file.wBufOffset > 0) {
+      int32_t nw = taosWriteFile(ctx->file.pFile, ctx->file.wBuf, ctx->file.wBufOffset);
+      ctx->file.wBufOffset = 0;
+    }
     taosFsyncFile(ctx->file.pFile);
   } else {
     // do nothing
@@ -157,10 +192,15 @@ IFileCtx* idxFileCtxCreate(WriterType type, const char* path, bool readOnly, int
       ctx->file.pFile = taosOpenFile(path, TD_FILE_CREATE | TD_FILE_WRITE | TD_FILE_APPEND);
       taosFtruncateFile(ctx->file.pFile, 0);
       taosStatFile(path, &ctx->file.size, NULL);
+
+      ctx->file.wBufOffset = 0;
+      ctx->file.wBufCap = kBlockSize * 4;
+      ctx->file.wBuf = taosMemoryCalloc(1, ctx->file.wBufCap);
     } else {
       ctx->file.pFile = taosOpenFile(path, TD_FILE_READ);
-
       taosFStatFile(ctx->file.pFile, &ctx->file.size, NULL);
+      ctx->file.wBufOffset = 0;
+
 #ifdef USE_MMAP
       ctx->file.ptr = (char*)tfMmapReadOnly(ctx->file.pFile, ctx->file.size);
 #endif
@@ -195,17 +235,18 @@ void idxFileCtxDestroy(IFileCtx* ctx, bool remove) {
   if (ctx->type == TMEMORY) {
     taosMemoryFree(ctx->mem.buf);
   } else {
+    if (ctx->file.wBufOffset > 0) {
+      int32_t nw = taosWriteFile(ctx->file.pFile, ctx->file.wBuf, ctx->file.wBufOffset);
+      ctx->file.wBufOffset = 0;
+    }
     ctx->flush(ctx);
+    taosMemoryFreeClear(ctx->file.wBuf);
     taosCloseFile(&ctx->file.pFile);
     if (ctx->file.readOnly) {
 #ifdef USE_MMAP
       munmap(ctx->file.ptr, ctx->file.size);
 #endif
     }
-    if (ctx->file.readOnly == false) {
-      int64_t file_size = 0;
-      taosStatFile(ctx->file.buf, &file_size, NULL);
-    }
     if (remove) {
       unlink(ctx->file.buf);
     }
diff --git a/source/os/src/osEnv.c b/source/os/src/osEnv.c
index c4627ffb7559a045ffae9a32e9a01a87a0e32de9..7f0e6d1dee22972cc633c78421a3ee1e6b297e36 100644
--- a/source/os/src/osEnv.c
+++ b/source/os/src/osEnv.c
@@ -37,11 +37,11 @@ float           tsNumOfCores = 0;
 int64_t         tsTotalMemoryKB = 0;
 char           *tsProcPath = NULL;
 
-char            tsSIMDBuiltins = 0;
-char            tsSSE42Enable = 0;
-char            tsAVXEnable = 0;
-char            tsAVX2Enable = 0;
-char            tsFMAEnable = 0;
+char tsSIMDBuiltins = 0;
+char tsSSE42Enable = 0;
+char tsAVXEnable = 0;
+char tsAVX2Enable = 0;
+char tsFMAEnable = 0;
 
 void osDefaultInit() {
   taosSeedRand(taosSafeRand());
diff --git a/source/os/src/osString.c b/source/os/src/osString.c
index f03778de2f8cf9020e9540c581c30f9ca44947b6..5419da1c0ce49fe8e61cbf030ad540918835f465 100644
--- a/source/os/src/osString.c
+++ b/source/os/src/osString.c
@@ -116,39 +116,36 @@ TdUcs4 *tasoUcs4Copy(TdUcs4 *target_ucs4, TdUcs4 *source_ucs4, int32_t len_ucs4)
   return memcpy(target_ucs4, source_ucs4, len_ucs4 * sizeof(TdUcs4));
 }
 
-int32_t taosUcs4ToMbs(TdUcs4 *ucs4, int32_t ucs4_max_len, char *mbs) {
-#ifdef DISALLOW_NCHAR_WITHOUT_ICONV
-  printf("Nchar cannot be read and written without iconv, please install iconv library and recompile TDengine.\n");
-  return -1;
-#else
-  iconv_t cd = iconv_open(tsCharset, DEFAULT_UNICODE_ENCODEC);
-  size_t  ucs4_input_len = ucs4_max_len;
-  size_t  outLen = ucs4_max_len;
-  if (iconv(cd, (char **)&ucs4, &ucs4_input_len, &mbs, &outLen) == -1) {
-    iconv_close(cd);
-    return -1;
-  }
-
-  iconv_close(cd);
-  return (int32_t)(ucs4_max_len - outLen);
-#endif
-}
-
 typedef struct {
   iconv_t conv;
   int8_t  inUse;
 } SConv;
 
-SConv  *gConv = NULL;
-int32_t convUsed = 0;
-int32_t gConvMaxNum = 0;
+typedef enum { M2C = 0, C2M } ConvType;
+
+// 0: Mbs --> Ucs4
+// 1: Ucs4--> Mbs
+SConv  *gConv[2] = {NULL, NULL};
+int32_t convUsed[2] = {0, 0};
+int32_t gConvMaxNum[2] = {0, 0};
 
 int32_t taosConvInit(void) {
-  gConvMaxNum = 512;
-  gConv = taosMemoryCalloc(gConvMaxNum, sizeof(SConv));
-  for (int32_t i = 0; i < gConvMaxNum; ++i) {
-    gConv[i].conv = iconv_open(DEFAULT_UNICODE_ENCODEC, tsCharset);
-    if ((iconv_t)-1 == gConv[i].conv || (iconv_t)0 == gConv[i].conv) {
+  int8_t M2C = 0;
+  gConvMaxNum[M2C] = 512;
+  gConvMaxNum[1 - M2C] = 512;
+
+  gConv[M2C] = taosMemoryCalloc(gConvMaxNum[M2C], sizeof(SConv));
+  gConv[1 - M2C] = taosMemoryCalloc(gConvMaxNum[1 - M2C], sizeof(SConv));
+
+  for (int32_t i = 0; i < gConvMaxNum[M2C]; ++i) {
+    gConv[M2C][i].conv = iconv_open(DEFAULT_UNICODE_ENCODEC, tsCharset);
+    if ((iconv_t)-1 == gConv[M2C][i].conv || (iconv_t)0 == gConv[M2C][i].conv) {
+      return -1;
+    }
+  }
+  for (int32_t i = 0; i < gConvMaxNum[1 - M2C]; ++i) {
+    gConv[1 - M2C][i].conv = iconv_open(tsCharset, DEFAULT_UNICODE_ENCODEC);
+    if ((iconv_t)-1 == gConv[1 - M2C][i].conv || (iconv_t)0 == gConv[1 - M2C][i].conv) {
       return -1;
     }
   }
@@ -157,23 +154,33 @@ int32_t taosConvInit(void) {
 }
 
 void taosConvDestroy() {
-  for (int32_t i = 0; i < gConvMaxNum; ++i) {
-    iconv_close(gConv[i].conv);
+  int8_t M2C = 0;
+  for (int32_t i = 0; i < gConvMaxNum[M2C]; ++i) {
+    iconv_close(gConv[M2C][i].conv);
+  }
+  for (int32_t i = 0; i < gConvMaxNum[1 - M2C]; ++i) {
+    iconv_close(gConv[1 - M2C][i].conv);
   }
-  taosMemoryFreeClear(gConv);
-  gConvMaxNum = -1;
+  taosMemoryFreeClear(gConv[M2C]);
+  taosMemoryFreeClear(gConv[1 - M2C]);
+  gConvMaxNum[M2C] = -1;
+  gConvMaxNum[1 - M2C] = -1;
 }
 
-iconv_t taosAcquireConv(int32_t *idx) {
-  if (gConvMaxNum <= 0) {
+iconv_t taosAcquireConv(int32_t *idx, ConvType type) {
+  if (gConvMaxNum[type] <= 0) {
     *idx = -1;
-    return iconv_open(DEFAULT_UNICODE_ENCODEC, tsCharset);
+    if (type == M2C) {
+      return iconv_open(DEFAULT_UNICODE_ENCODEC, tsCharset);
+    } else {
+      return iconv_open(tsCharset, DEFAULT_UNICODE_ENCODEC);
+    }
   }
 
   while (true) {
-    int32_t used = atomic_add_fetch_32(&convUsed, 1);
-    if (used > gConvMaxNum) {
-      used = atomic_sub_fetch_32(&convUsed, 1);
+    int32_t used = atomic_add_fetch_32(&convUsed[type], 1);
+    if (used > gConvMaxNum[type]) {
+      used = atomic_sub_fetch_32(&convUsed[type], 1);
       sched_yield();
       continue;
     }
@@ -181,31 +188,31 @@ iconv_t taosAcquireConv(int32_t *idx) {
     break;
   }
 
-  int32_t startId = taosGetSelfPthreadId() % gConvMaxNum;
+  int32_t startId = taosGetSelfPthreadId() % gConvMaxNum[type];
   while (true) {
-    if (gConv[startId].inUse) {
-      startId = (startId + 1) % gConvMaxNum;
+    if (gConv[type][startId].inUse) {
+      startId = (startId + 1) % gConvMaxNum[type];
       continue;
     }
 
-    int8_t old = atomic_val_compare_exchange_8(&gConv[startId].inUse, 0, 1);
+    int8_t old = atomic_val_compare_exchange_8(&gConv[type][startId].inUse, 0, 1);
     if (0 == old) {
       break;
     }
   }
 
   *idx = startId;
-  return gConv[startId].conv;
+  return gConv[type][startId].conv;
 }
 
-void taosReleaseConv(int32_t idx, iconv_t conv) {
+void taosReleaseConv(int32_t idx, iconv_t conv, ConvType type) {
   if (idx < 0) {
     iconv_close(conv);
     return;
   }
 
-  atomic_store_8(&gConv[idx].inUse, 0);
-  atomic_sub_fetch_32(&convUsed, 1);
+  atomic_store_8(&gConv[type][idx].inUse, 0);
+  atomic_sub_fetch_32(&convUsed[type], 1);
 }
 
 bool taosMbsToUcs4(const char *mbs, size_t mbsLength, TdUcs4 *ucs4, int32_t ucs4_max_len, int32_t *len) {
@@ -216,15 +223,15 @@ bool taosMbsToUcs4(const char *mbs, size_t mbsLength, TdUcs4 *ucs4, int32_t ucs4
   memset(ucs4, 0, ucs4_max_len);
 
   int32_t idx = -1;
-  iconv_t conv = taosAcquireConv(&idx);
+  iconv_t conv = taosAcquireConv(&idx, M2C);
   size_t  ucs4_input_len = mbsLength;
   size_t  outLeft = ucs4_max_len;
   if (iconv(conv, (char **)&mbs, &ucs4_input_len, (char **)&ucs4, &outLeft) == -1) {
-    taosReleaseConv(idx, conv);
+    taosReleaseConv(idx, conv, M2C);
     return false;
   }
 
-  taosReleaseConv(idx, conv);
+  taosReleaseConv(idx, conv, M2C);
   if (len != NULL) {
     *len = (int32_t)(ucs4_max_len - outLeft);
     if (*len < 0) {
@@ -236,6 +243,24 @@ bool taosMbsToUcs4(const char *mbs, size_t mbsLength, TdUcs4 *ucs4, int32_t ucs4
 #endif
 }
 
+int32_t taosUcs4ToMbs(TdUcs4 *ucs4, int32_t ucs4_max_len, char *mbs) {
+#ifdef DISALLOW_NCHAR_WITHOUT_ICONV
+  printf("Nchar cannot be read and written without iconv, please install iconv library and recompile TDengine.\n");
+  return -1;
+#else
+
+  int32_t idx = -1;
+  iconv_t conv = taosAcquireConv(&idx, C2M);
+  size_t  ucs4_input_len = ucs4_max_len;
+  size_t  outLen = ucs4_max_len;
+  if (iconv(conv, (char **)&ucs4, &ucs4_input_len, &mbs, &outLen) == -1) {
+    taosReleaseConv(idx, conv, C2M);
+    return -1;
+  }
+  taosReleaseConv(idx, conv, C2M);
+  return (int32_t)(ucs4_max_len - outLen);
+#endif
+}
 bool taosValidateEncodec(const char *encodec) {
 #ifdef DISALLOW_NCHAR_WITHOUT_ICONV
   printf("Nchar cannot be read and written without iconv, please install iconv library and recompile TDengine.\n");