diff --git a/source/client/src/clientSml.c b/source/client/src/clientSml.c
index fe1946d77d..9241b3c5d4 100644
--- a/source/client/src/clientSml.c
+++ b/source/client/src/clientSml.c
@@ -79,7 +79,7 @@
 #define NCHAR_ADD_LEN  3  // L"nchar"   3 means L" "
 
 #define MAX_RETRY_TIMES 5
-#define LINE_BATCH      2000
+#define LINE_BATCH      2
 //=================================================================================================
 typedef TSDB_SML_PROTOCOL_TYPE SMLProtocolType;
 
@@ -2199,7 +2199,7 @@ static int32_t smlParseTelnetLine(SSmlHandle *info, void *data, const int len) {
   }
 
   if (info->protocol == TSDB_SML_TELNET_PROTOCOL) {
-    ret = smlParseTelnetString(info, (const char *)data, POINTER_SHIFT(data, len), tinfo, cols);
+    ret = smlParseTelnetString(info, (const char *)data, (char*)data + len, tinfo, cols);
   } else if (info->protocol == TSDB_SML_JSON_PROTOCOL) {
     ret = smlParseJSONString(info, (cJSON *)data, tinfo, cols);
   } else {
@@ -2408,6 +2408,9 @@ static int32_t smlParseLine(SSmlHandle *info, char *lines[], char* rawLine, char
         }
         len++;
       }
+      if(info->protocol == TSDB_SML_LINE_PROTOCOL && tmp[0] == '#'){ // this line is comment
+        continue;
+      }
     }
 
     if (info->protocol == TSDB_SML_LINE_PROTOCOL) {
@@ -2418,7 +2421,7 @@ static int32_t smlParseLine(SSmlHandle *info, char *lines[], char* rawLine, char
       ASSERT(0);
     }
     if (code != TSDB_CODE_SUCCESS) {
-      uError("SML:0x%" PRIx64 " smlParseLine failed. line %d : %s", info->id, i, lines[i]);
+      uError("SML:0x%" PRIx64 " smlParseLine failed. line %d : %s", info->id, i, tmp);
       return code;
     }
   }
@@ -2692,11 +2695,16 @@ TAOS_RES *taos_schemaless_insert_raw(TAOS* taos, char* lines, int len, int32_t *
   }
 
   int numLines = 0;
+  *totalRows = 0;
+  char *tmp = lines;
   for(int i = 0; i < len; i++){
     if(lines[i] == '\n' || i == len - 1){
       numLines++;
+      if(tmp[0] != '#' || protocol != TSDB_SML_LINE_PROTOCOL){    //ignore comment
+        (*totalRows)++;
+      }
+      tmp = lines + i + 1;
     }
   }
-  *totalRows = numLines;
   return taos_schemaless_insert_inner(request, NULL, lines, lines + len, numLines, protocol, precision);
 }
diff --git a/source/client/test/smlTest.cpp b/source/client/test/smlTest.cpp
index ab4442eca7..54778e87a7 100644
--- a/source/client/test/smlTest.cpp
+++ b/source/client/test/smlTest.cpp
@@ -44,7 +44,7 @@ TEST(testCase, smlParseInfluxString_Test) {
   char *tmp = "\\,st,t1=3,t2=4,t3=t3 c1=3i64,c3=\"passit hello,c1=2\",c2=false,c4=4f64 1626006833639000000    ,32,c=3";
   char *sql = (char *)taosMemoryCalloc(256, 1);
   memcpy(sql, tmp, strlen(tmp) + 1);
-  int ret = smlParseInfluxString(sql, &elements, &msgBuf);
+  int ret = smlParseInfluxString(sql, sql + strlen(sql), &elements, &msgBuf);
   ASSERT_EQ(ret, 0);
   ASSERT_EQ(elements.measure, sql);
   ASSERT_EQ(elements.measureLen, strlen(",st"));
@@ -63,14 +63,14 @@ TEST(testCase, smlParseInfluxString_Test) {
   tmp = "st,t1=3,t2=4,t3=t3 c1=3i64,c3=\"passit hello,c1=2,c2=false,c4=4f64 1626006833639000000";
   memcpy(sql, tmp, strlen(tmp) + 1);
   memset(&elements, 0, sizeof(SSmlLineInfo));
-  ret = smlParseInfluxString(sql, &elements, &msgBuf);
+  ret = smlParseInfluxString(sql, sql + strlen(sql), &elements, &msgBuf);
   ASSERT_NE(ret, 0);
 
   // case 3  false
   tmp = "st, t1=3,t2=4,t3=t3 c1=3i64,c3=\"passit hello,c1=2,c2=false,c4=4f64 1626006833639000000";
   memcpy(sql, tmp, strlen(tmp) + 1);
   memset(&elements, 0, sizeof(SSmlLineInfo));
-  ret = smlParseInfluxString(sql, &elements, &msgBuf);
+  ret = smlParseInfluxString(sql, sql + strlen(sql), &elements, &msgBuf);
   ASSERT_EQ(ret, 0);
   ASSERT_EQ(elements.cols, sql + elements.measureTagsLen + 1);
   ASSERT_EQ(elements.colsLen, strlen("t1=3,t2=4,t3=t3"));
@@ -79,7 +79,7 @@ TEST(testCase, smlParseInfluxString_Test) {
   tmp = "st, c1=3i64,c3=\"passit hello,c1=2\",c2=false,c4=4f64 1626006833639000000";
   memcpy(sql, tmp, strlen(tmp) + 1);
   memset(&elements, 0, sizeof(SSmlLineInfo));
-  ret = smlParseInfluxString(sql, &elements, &msgBuf);
+  ret = smlParseInfluxString(sql, sql + strlen(sql), &elements, &msgBuf);
   ASSERT_EQ(ret, 0);
   ASSERT_EQ(elements.measure, sql);
   ASSERT_EQ(elements.measureLen, strlen("st"));
@@ -98,7 +98,7 @@ TEST(testCase, smlParseInfluxString_Test) {
   tmp = " st   c1=3i64,c3=\"passit hello,c1=2\",c2=false,c4=4f64  1626006833639000000 ";
   memcpy(sql, tmp, strlen(tmp) + 1);
   memset(&elements, 0, sizeof(SSmlLineInfo));
-  ret = smlParseInfluxString(sql, &elements, &msgBuf);
+  ret = smlParseInfluxString(sql, sql + strlen(sql), &elements, &msgBuf);
   ASSERT_EQ(ret, 0);
   ASSERT_EQ(elements.measure, sql + 1);
   ASSERT_EQ(elements.measureLen, strlen("st"));
@@ -116,21 +116,21 @@ TEST(testCase, smlParseInfluxString_Test) {
   tmp = " st   c1=3i64,c3=\"passit hello,c1=2\",c2=false,c4=4f64   ";
   memcpy(sql, tmp, strlen(tmp) + 1);
   memset(&elements, 0, sizeof(SSmlLineInfo));
-  ret = smlParseInfluxString(sql, &elements, &msgBuf);
+  ret = smlParseInfluxString(sql, sql + strlen(sql), &elements, &msgBuf);
   ASSERT_EQ(ret, 0);
 
   // case 7
   tmp = " st   ,   ";
   memcpy(sql, tmp, strlen(tmp) + 1);
   memset(&elements, 0, sizeof(SSmlLineInfo));
-  ret = smlParseInfluxString(sql, &elements, &msgBuf);
+  ret = smlParseInfluxString(sql, sql + strlen(sql), &elements, &msgBuf);
   ASSERT_EQ(ret, 0);
 
   // case 8 false
   tmp = ", st   ,   ";
   memcpy(sql, tmp, strlen(tmp) + 1);
   memset(&elements, 0, sizeof(SSmlLineInfo));
-  ret = smlParseInfluxString(sql, &elements, &msgBuf);
+  ret = smlParseInfluxString(sql, sql + strlen(sql), &elements, &msgBuf);
   ASSERT_NE(ret, 0);
   taosMemoryFree(sql);
 }
@@ -542,7 +542,7 @@ TEST(testCase, smlParseTelnetLine_error_Test) {
       "sys.procs.running 1479496100 42 host= web01",
   };
   for (int i = 0; i < sizeof(sql) / sizeof(sql[0]); i++) {
-    int ret = smlParseTelnetLine(info, (void *)sql[i]);
+    int ret = smlParseTelnetLine(info, (void *)sql[i], strlen(sql[i]));
     ASSERT_NE(ret, 0);
   }
 
@@ -561,7 +561,7 @@ TEST(testCase, smlParseTelnetLine_diff_type_Test) {
 
   int ret = TSDB_CODE_SUCCESS;
   for (int i = 0; i < sizeof(sql) / sizeof(sql[0]); i++) {
-    ret = smlParseTelnetLine(info, (void *)sql[i]);
+    ret = smlParseTelnetLine(info, (void *)sql[i], strlen(sql[i]));
     if (ret != TSDB_CODE_SUCCESS) break;
   }
   ASSERT_NE(ret, 0);
@@ -617,7 +617,7 @@ TEST(testCase, smlParseTelnetLine_json_error_Test) {
 
   int ret = TSDB_CODE_SUCCESS;
   for (int i = 0; i < sizeof(sql) / sizeof(sql[0]); i++) {
-    ret = smlParseTelnetLine(info, (void *)sql[i]);
+    ret = smlParseTelnetLine(info, (void *)sql[i], strlen(sql[i]));
     ASSERT_NE(ret, 0);
   }
 
@@ -653,7 +653,7 @@ TEST(testCase, smlParseTelnetLine_diff_json_type1_Test) {
 
   int ret = TSDB_CODE_SUCCESS;
   for (int i = 0; i < sizeof(sql) / sizeof(sql[0]); i++) {
-    ret = smlParseTelnetLine(info, (void *)sql[i]);
+    ret = smlParseTelnetLine(info, (void *)sql[i], strlen(sql[i]));
     if (ret != TSDB_CODE_SUCCESS) break;
   }
   ASSERT_NE(ret, 0);
@@ -688,7 +688,7 @@ TEST(testCase, smlParseTelnetLine_diff_json_type2_Test) {
   };
   int ret = TSDB_CODE_SUCCESS;
   for (int i = 0; i < sizeof(sql) / sizeof(sql[0]); i++) {
-    ret = smlParseTelnetLine(info, (void *)sql[i]);
+    ret = smlParseTelnetLine(info, (void *)sql[i], strlen(sql[i]));
     if (ret != TSDB_CODE_SUCCESS) break;
   }
   ASSERT_NE(ret, 0);
@@ -1002,7 +1002,7 @@ TEST(testCase, sml_col_4096_Test) {
 
   int ret = TSDB_CODE_SUCCESS;
   for (int i = 0; i < sizeof(sql) / sizeof(sql[0]); i++) {
-    ret = smlParseInfluxLine(info, sql[i]);
+    ret = smlParseInfluxLine(info, sql[i], strlen(sql[i]));
     if (ret != TSDB_CODE_SUCCESS) break;
   }
   ASSERT_NE(ret, 0);
diff --git a/utils/test/c/sml_test.c b/utils/test/c/sml_test.c
index b6d8d75ba0..09079d3a26 100644
--- a/utils/test/c/sml_test.c
+++ b/utils/test/c/sml_test.c
@@ -1155,37 +1155,64 @@ int smlProcess_18784_Test() {
   return code;
 }
 
+int sml_19221_Test() {
+  TAOS *taos = taos_connect("localhost", "root", "taosdata", NULL, 0);
+
+  TAOS_RES *pRes = taos_query(taos, "create database if not exists sml_db schemaless 1");
+  taos_free_result(pRes);
+
+  const char *sql[] = {
+      "qelhxo,id=pnnqhsa,t0=t,t1=127i8 c11=L\"ncharColValue\",c0=t,c1=127i8 1626006833639000000\nqelhxo,id=pnnhsa,t0=t,t1=127i8 c11=L\"ncharColValue\",c0=t,c1=127i8 1626006833639000000\nqelhxo,id=pnqhsa,t0=t,t1=127i8 c11=L\"ncharColValue\",c0=t,c1=127i8 1626006833639000000",
+  };
+
+  pRes = taos_query(taos, "use sml_db");
+  taos_free_result(pRes);
+
+  void* tmp = taosMemoryCalloc(256, 1);
+  memcpy(tmp, sql[0], strlen(sql[0]));
+  *(char*)(tmp+44) = 0;
+  int32_t totalRows = 0;
+  pRes = taos_schemaless_insert_raw(taos, tmp, strlen(sql[0]), &totalRows, TSDB_SML_LINE_PROTOCOL, TSDB_SML_TIMESTAMP_NANO_SECONDS);
+
+  printf("%s result:%s\n", __FUNCTION__, taos_errstr(pRes));
+  int code = taos_errno(pRes);
+  taos_free_result(pRes);
+  return code;
+}
+
 int main(int argc, char *argv[]) {
   int ret = 0;
-  ret = smlProcess_influx_Test();
-  ASSERT(!ret);
-  ret = smlProcess_telnet_Test();
-  ASSERT(!ret);
-  ret = smlProcess_json1_Test();
-  ASSERT(!ret);
-  ret = smlProcess_json2_Test();
-  ASSERT(!ret);
-  ret = smlProcess_json3_Test();
-  ASSERT(!ret);
-  ret = smlProcess_json4_Test();
-  ASSERT(!ret);
-  ret = sml_TD15662_Test();
-  ASSERT(!ret);
-  ret = sml_TD15742_Test();
-  ASSERT(!ret);
-  ret = sml_16384_Test();
-  ASSERT(!ret);
-  ret = sml_oom_Test();
-  ASSERT(!ret);
-  ret = sml_16368_Test();
-  ASSERT(!ret);
-  ret = sml_dup_time_Test();
-  ASSERT(!ret);
-  ret = sml_16960_Test();
-  ASSERT(!ret);
-  ret = sml_add_tag_col_Test();
-  ASSERT(!ret);
-  ret = smlProcess_18784_Test();
+//  ret = smlProcess_influx_Test();
+//  ASSERT(!ret);
+//  ret = smlProcess_telnet_Test();
+//  ASSERT(!ret);
+//  ret = smlProcess_json1_Test();
+//  ASSERT(!ret);
+//  ret = smlProcess_json2_Test();
+//  ASSERT(!ret);
+//  ret = smlProcess_json3_Test();
+//  ASSERT(!ret);
+//  ret = smlProcess_json4_Test();
+//  ASSERT(!ret);
+//  ret = sml_TD15662_Test();
+//  ASSERT(!ret);
+//  ret = sml_TD15742_Test();
+//  ASSERT(!ret);
+//  ret = sml_16384_Test();
+//  ASSERT(!ret);
+//  ret = sml_oom_Test();
+//  ASSERT(!ret);
+//  ret = sml_16368_Test();
+//  ASSERT(!ret);
+//  ret = sml_dup_time_Test();
+//  ASSERT(!ret);
+//  ret = sml_16960_Test();
+//  ASSERT(!ret);
+//  ret = sml_add_tag_col_Test();
+//  ASSERT(!ret);
+//  ret = smlProcess_18784_Test();
+//  ASSERT(!ret);
+  ret = sml_19221_Test();
   ASSERT(!ret);
   return ret;
 }