diff --git a/source/client/src/clientSml.c b/source/client/src/clientSml.c
index 4cef67b34da53f3d6f86f9ff5107f82e359ca14d..d1d73259097d8a5afbd15c9fde06242f661bb5e6 100644
--- a/source/client/src/clientSml.c
+++ b/source/client/src/clientSml.c
@@ -303,7 +303,7 @@ static int32_t smlApplySchemaAction(SSmlHandle* info, SSchemaAction* action) {
           uError("SML:0x%" PRIx64 " apply schema action. reset query cache. error: %s", info->id, taos_errstr(res2));
         }
         taos_free_result(res2);
-        taosMsleep(500);
+        taosMsleep(10);
       }
       break;
     }
@@ -327,7 +327,7 @@ static int32_t smlApplySchemaAction(SSmlHandle* info, SSchemaAction* action) {
           uError("SML:0x%" PRIx64 " apply schema action. reset query cache. error: %s", info->id, taos_errstr(res2));
         }
         taos_free_result(res2);
-        taosMsleep(500);
+        taosMsleep(10);
       }
       break;
     }
@@ -350,7 +350,7 @@ static int32_t smlApplySchemaAction(SSmlHandle* info, SSchemaAction* action) {
           uError("SML:0x%" PRIx64 " apply schema action. reset query cache. error: %s", info->id, taos_errstr(res2));
         }
         taos_free_result(res2);
-        taosMsleep(500);
+        taosMsleep(10);
       }
       break;
     }
@@ -373,7 +373,7 @@ static int32_t smlApplySchemaAction(SSmlHandle* info, SSchemaAction* action) {
           uError("SML:0x%" PRIx64 " apply schema action. reset query cache. error: %s", info->id, taos_errstr(res2));
         }
         taos_free_result(res2);
-        taosMsleep(500);
+        taosMsleep(10);
       }
       break;
     }
@@ -424,7 +424,7 @@ static int32_t smlApplySchemaAction(SSmlHandle* info, SSchemaAction* action) {
           uError("SML:0x%" PRIx64 " apply schema action. reset query cache. error: %s", info->id, taos_errstr(res2));
         }
         taos_free_result(res2);
-        taosMsleep(500);
+        taosMsleep(10);
       }
       break;
     }
@@ -461,18 +461,18 @@ static int32_t smlProcessSchemaAction(SSmlHandle* info, SSchema* schemaField, SH
 
 static int32_t smlModifyDBSchemas(SSmlHandle* info) {
   int32_t code = 0;
+  SEpSet ep = getEpSet_s(&info->taos->pAppInfo->mgmtEp);
+  SName pName = {TSDB_TABLE_NAME_T, info->taos->acctId, {0}, {0}};
+  strcpy(pName.dbname, info->pRequest->pDb);
 
   SSmlSTableMeta** tableMetaSml = (SSmlSTableMeta**)taosHashIterate(info->superTables, NULL);
   while (tableMetaSml) {
     SSmlSTableMeta* sTableData = *tableMetaSml;
-
     STableMeta *pTableMeta = NULL;
-    SEpSet ep = getEpSet_s(&info->taos->pAppInfo->mgmtEp);
 
     size_t superTableLen = 0;
     void *superTable = taosHashGetKey(tableMetaSml, &superTableLen);
-    SName pName = {TSDB_TABLE_NAME_T, info->taos->acctId, {0}, {0}};
-    strcpy(pName.dbname, info->pRequest->pDb);
+    memset(pName.tname, 0, TSDB_TABLE_NAME_LEN);
     memcpy(pName.tname, superTable, superTableLen);
 
     code = catalogGetSTableMeta(info->pCatalog, info->taos->pAppInfo->pTransporter, &ep, &pName, &pTableMeta);
@@ -487,7 +487,7 @@ static int32_t smlModifyDBSchemas(SSmlHandle* info) {
       code = smlApplySchemaAction(info, &schemaAction);
       if (code != TSDB_CODE_SUCCESS) {
         uError("SML:0x%"PRIx64" smlApplySchemaAction failed. can not create %s", info->id, schemaAction.createSTable.sTableName);
-        return code;
+        goto end;
       }
       info->cost.numOfCreateSTables++;
     }else if (code == TSDB_CODE_SUCCESS) {
@@ -502,7 +502,7 @@ static int32_t smlModifyDBSchemas(SSmlHandle* info) {
       code = smlProcessSchemaAction(info, pTableMeta->schema, hashTmp, sTableData->tags, &schemaAction, true);
       if (code != TSDB_CODE_SUCCESS) {
         taosHashCleanup(hashTmp);
-        return code;
+        goto end;
       }
 
       taosHashClear(hashTmp);
@@ -512,29 +512,33 @@ static int32_t smlModifyDBSchemas(SSmlHandle* info) {
       code = smlProcessSchemaAction(info, pTableMeta->schema, hashTmp, sTableData->cols, &schemaAction, false);
       taosHashCleanup(hashTmp);
       if (code != TSDB_CODE_SUCCESS) {
-        return code;
+        goto end;
       }
 
-      code = catalogRefreshTableMeta(info->pCatalog, info->taos->pAppInfo->pTransporter, &ep, &pName, -1);
+      code = catalogRefreshTableMeta(info->pCatalog, info->taos->pAppInfo->pTransporter, &ep, &pName, 1);
       if (code != TSDB_CODE_SUCCESS) {
-        return code;
+        goto end;
       }
     } else {
       uError("SML:0x%"PRIx64" load table meta error: %s", info->id, tstrerror(code));
-      return code;
+      goto end;
     }
     if(pTableMeta) taosMemoryFree(pTableMeta);
 
     code = catalogGetSTableMeta(info->pCatalog, info->taos->pAppInfo->pTransporter, &ep, &pName, &pTableMeta);
     if (code != TSDB_CODE_SUCCESS) {
       uError("SML:0x%"PRIx64" catalogGetSTableMeta failed. super table name %s", info->id, (char*)superTable);
-      return code;
+      goto end;
     }
     sTableData->tableMeta = pTableMeta;
 
     tableMetaSml = (SSmlSTableMeta**)taosHashIterate(info->superTables, tableMetaSml);
   }
   return 0;
+
+end:
+  catalogRefreshTableMeta(info->pCatalog, info->taos->pAppInfo->pTransporter, &ep, &pName, 1);
+  return code;
 }
 
 //=========================================================================
@@ -1544,7 +1548,7 @@ static int32_t smlParseTSFromJSONObj(SSmlHandle *info, cJSON *root, int64_t *tsV
   }
 
   size_t typeLen = strlen(type->valuestring);
-  if (typeLen == 1 && type->valuestring[0] == 's') {
+  if (typeLen == 1 && (type->valuestring[0] == 's' || type->valuestring[0] == 'S')) {
     //seconds
     timeDouble = timeDouble * 1e9;
     if(smlDoubleToInt64OverFlow(timeDouble)){
@@ -1552,9 +1556,10 @@ static int32_t smlParseTSFromJSONObj(SSmlHandle *info, cJSON *root, int64_t *tsV
       return TSDB_CODE_TSC_INVALID_TIME_STAMP;
     }
     *tsVal = timeDouble;
-  } else if (typeLen == 2 && type->valuestring[1] == 's') {
+  } else if (typeLen == 2 && (type->valuestring[1] == 's' || type->valuestring[1] == 'S')) {
     switch (type->valuestring[0]) {
       case 'm':
+      case 'M':
         //milliseconds
         timeDouble = timeDouble * 1e6;
         if(smlDoubleToInt64OverFlow(timeDouble)){
@@ -1564,6 +1569,7 @@ static int32_t smlParseTSFromJSONObj(SSmlHandle *info, cJSON *root, int64_t *tsV
         *tsVal = timeDouble;
         break;
       case 'u':
+      case 'U':
         //microseconds
         timeDouble = timeDouble * 1e3;
         if(smlDoubleToInt64OverFlow(timeDouble)){
@@ -1573,6 +1579,7 @@ static int32_t smlParseTSFromJSONObj(SSmlHandle *info, cJSON *root, int64_t *tsV
         *tsVal = timeDouble;
         break;
       case 'n':
+      case 'N':
         //nanoseconds
         *tsVal = timeDouble;
         break;
@@ -2285,6 +2292,8 @@ static int32_t smlParseLine(SSmlHandle *info, char* lines[], int numLines){
 
 static int smlProcess(SSmlHandle *info, char* lines[], int numLines) {
   int32_t code = TSDB_CODE_SUCCESS;
+  int32_t retryNum = 0;
+
   info->cost.parseTime = taosGetTimestampUs();
 
   code = smlParseLine(info, lines, numLines);
@@ -2298,7 +2307,12 @@ static int smlProcess(SSmlHandle *info, char* lines[], int numLines) {
   info->cost.numOfCTables = taosHashGetSize(info->childTables);
 
   info->cost.schemaTime = taosGetTimestampUs();
-  code = smlModifyDBSchemas(info);
+
+  do{
+    code = smlModifyDBSchemas(info);
+    if (code == 0) break;
+  } while (retryNum++ < taosHashGetSize(info->superTables));
+
   if (code != 0) {
     uError("SML:0x%"PRIx64" smlModifyDBSchemas error : %s", info->id, tstrerror(code));
     goto cleanup;
@@ -2409,6 +2423,7 @@ TAOS_RES* taos_schemaless_insert(TAOS* taos, char* lines[], int numLines, int pr
   info->pRequest->code = smlProcess(info, lines, numLines);
 
 end:
+  info->taos->schemalessType = 0;
   uDebug("result:%s", info->msgBuf.buf);
   smlDestroyInfo(info);
   return (TAOS_RES*)request;
diff --git a/source/client/test/smlTest.cpp b/source/client/test/smlTest.cpp
index 3bfd26bb435d71ea72964920d13d32b0eba5ef2d..8137583978e170c8eba751f577c9ff2e2a3b5d00 100644
--- a/source/client/test/smlTest.cpp
+++ b/source/client/test/smlTest.cpp
@@ -1272,14 +1272,40 @@ TEST(testCase, sml_params_Test) {
   };
   TAOS_RES* res = taos_schemaless_insert(taos, (char**)sql, 1, TSDB_SML_LINE_PROTOCOL, TSDB_SML_TIMESTAMP_MILLI_SECONDS);
   ASSERT_EQ(taos_errno(res), TSDB_CODE_PAR_DB_NOT_SPECIFIED);
-  taos_free_result(pRes);
+  taos_free_result(res);
 
   pRes = taos_query(taos, "use param");
-  taos_free_result(pRes);
+  taos_free_result(res);
 
   res = taos_schemaless_insert(taos, (char**)sql, 1, TSDB_SML_LINE_PROTOCOL, TSDB_SML_TIMESTAMP_MILLI_SECONDS);
   ASSERT_EQ(taos_errno(res), TSDB_CODE_SML_INVALID_DB_CONF);
+  taos_free_result(res);
+}
+
+TEST(testCase, sml_16384_Test) {
+  TAOS *taos = taos_connect("localhost", "root", "taosdata", NULL, 0);
+  ASSERT_NE(taos, nullptr);
+
+  TAOS_RES* pRes = taos_query(taos, "create database if not exists d16384 schemaless 1");
+  taos_free_result(pRes);
+
+  const char *sql[] = {
+      "qelhxo,id=pnnqhsa,t0=t,t1=127i8 c0=t,c1=127i8 1626006833639000000",
+  };
+
+  pRes = taos_query(taos, "use d16384");
   taos_free_result(pRes);
+
+  TAOS_RES* res = taos_schemaless_insert(taos, (char**)sql, 1, TSDB_SML_LINE_PROTOCOL, 0);
+  ASSERT_EQ(taos_errno(res), 0);
+  taos_free_result(res);
+
+  const char *sql1[] = {
+      "qelhxo,id=pnnqhsa,t0=t,t1=127i8 c0=f,c1=127i8,c11=L\"ncharColValue\",c10=t 1626006833639000000",
+  };
+  TAOS_RES* res1 = taos_schemaless_insert(taos, (char**)sql1, 1, TSDB_SML_LINE_PROTOCOL, 0);
+  ASSERT_EQ(taos_errno(res1), 0);
+  taos_free_result(res1);
 }
 
 TEST(testCase, sml_oom_Test) {
@@ -1303,3 +1329,29 @@ TEST(testCase, sml_oom_Test) {
   ASSERT_EQ(taos_errno(res), 0);
   taos_free_result(pRes);
 }
+
+TEST(testCase, sml_16368_Test) {
+  TAOS *taos = taos_connect("localhost", "root", "taosdata", NULL, 0);
+  ASSERT_NE(taos, nullptr);
+
+  TAOS_RES* pRes = taos_query(taos, "create database if not exists d16368 schemaless 1");
+  taos_free_result(pRes);
+
+  pRes = taos_query(taos, "use d16368");
+  taos_free_result(pRes);
+
+  const char *sql[] = {
+      "[{\"metric\": \"st123456\", \"timestamp\": {\"value\": 1626006833639000, \"type\": \"us\"}, \"value\": 1, \"tags\": {\"t1\": 3, \"t2\": {\"value\": 4, \"type\": \"double\"}, \"t3\": {\"value\": \"t3\", \"type\": \"binary\"}}},\n"
+      "{\"metric\": \"st123456\", \"timestamp\": {\"value\": 1626006833739000, \"type\": \"us\"}, \"value\": 2, \"tags\": {\"t1\": {\"value\": 4, \"type\": \"double\"}, \"t3\": {\"value\": \"t4\", \"type\": \"binary\"}, \"t2\": {\"value\": 5, \"type\": \"double\"}, \"t4\": {\"value\": 5, \"type\": \"double\"}}},\n"
+      "{\"metric\": \"stb_name\", \"timestamp\": {\"value\": 1626006833639100, \"type\": \"us\"}, \"value\": 3, \"tags\": {\"t2\": {\"value\": 5, \"type\": \"double\"}, \"t3\": {\"value\": \"ste\", \"type\": \"nchar\"}}},\n"
+      "{\"metric\": \"stf567890\", \"timestamp\": {\"value\": 1626006833639200, \"type\": \"us\"}, \"value\": 4, \"tags\": {\"t1\": {\"value\": 4, \"type\": \"bigint\"}, \"t3\": {\"value\": \"t4\", \"type\": \"binary\"}, \"t2\": {\"value\": 5, \"type\": \"double\"}, \"t4\": {\"value\": 5, \"type\": \"double\"}}},\n"
+      "{\"metric\": \"st123456\", \"timestamp\": {\"value\": 1626006833639300, \"type\": \"us\"}, \"value\": {\"value\": 5, \"type\": \"double\"}, \"tags\": {\"t1\": {\"value\": 4, \"type\": \"double\"}, \"t2\": 5.0, \"t3\": {\"value\": \"t4\", \"type\": \"binary\"}}},\n"
+      "{\"metric\": \"stb_name\", \"timestamp\": {\"value\": 1626006833639400, \"type\": \"us\"}, \"value\": {\"value\": 6, \"type\": \"double\"}, \"tags\": {\"t2\": 5.0, \"t3\": {\"value\": \"ste2\", \"type\": \"nchar\"}}},\n"
+      "{\"metric\": \"stb_name\", \"timestamp\": {\"value\": 1626006834639400, \"type\": \"us\"}, \"value\": {\"value\": 7, \"type\": \"double\"}, \"tags\": {\"t2\": {\"value\": 5.0, \"type\": \"double\"}, \"t3\": {\"value\": \"ste2\", \"type\": \"nchar\"}}},\n"
+      "{\"metric\": \"st123456\", \"timestamp\": {\"value\": 1626006833839006, \"type\": \"us\"}, \"value\": {\"value\": 8, \"type\": \"double\"}, \"tags\": {\"t1\": {\"value\": 4, \"type\": \"double\"}, \"t3\": {\"value\": \"t4\", \"type\": \"binary\"}, \"t2\": {\"value\": 5, \"type\": \"double\"}, \"t4\": {\"value\": 5, \"type\": \"double\"}}},\n"
+      "{\"metric\": \"st123456\", \"timestamp\": {\"value\": 1626006833939007, \"type\": \"us\"}, \"value\": {\"value\": 9, \"type\": \"double\"}, \"tags\": {\"t1\": 4, \"t3\": {\"value\": \"t4\", \"type\": \"binary\"}, \"t2\": {\"value\": 5, \"type\": \"double\"}, \"t4\": {\"value\": 5, \"type\": \"double\"}}}]"
+  };
+  pRes = taos_schemaless_insert(taos, (char**)sql, sizeof(sql)/sizeof(sql[0]), TSDB_SML_JSON_PROTOCOL, TSDB_SML_TIMESTAMP_MICRO_SECONDS);
+  ASSERT_EQ(taos_errno(pRes), 0);
+  taos_free_result(pRes);
+}