diff --git a/include/libs/monitor/clientMonitor.h b/include/libs/monitor/clientMonitor.h
index 5e89c07b2b..aa6ee6c9fc 100644
--- a/include/libs/monitor/clientMonitor.h
+++ b/include/libs/monitor/clientMonitor.h
@@ -38,7 +38,7 @@ typedef enum {
   SLOW_LOG_READ_QUIT = 2,
 } SLOW_LOG_QUEUE_TYPE;
 
-#define SLOW_LOG_SEND_SIZE 32*1024
+#define SLOW_LOG_SEND_SIZE_MAX 128*1024*1024
 
 typedef struct {
   int64_t                    clusterId;
diff --git a/source/client/src/clientMonitor.c b/source/client/src/clientMonitor.c
index b30224c510..94b1fa9388 100644
--- a/source/client/src/clientMonitor.c
+++ b/source/client/src/clientMonitor.c
@@ -187,19 +187,19 @@ static void reportSendProcess(void* param, void* tmrId) {
 }
 
 static void sendAllCounter(){
-  MonitorClient** ppMonitor = (MonitorClient**)taosHashIterate(monitorCounterHash, NULL);
-  while (ppMonitor != NULL) {
+  MonitorClient** ppMonitor = NULL;
+  while ((ppMonitor = taosHashIterate(monitorSlowLogHash, ppMonitor))) {
     MonitorClient* pMonitor = *ppMonitor;
-    if (pMonitor != NULL){
-      SAppInstInfo* pInst = getAppInstByClusterId(pMonitor->clusterId);
-      if(pInst == NULL){
-        taosHashCancelIterate(monitorCounterHash, ppMonitor);
-        break;
-      }
-      SEpSet ep = getEpSet_s(&pInst->mgmtEp);
-      generateClusterReport(pMonitor->registry, pInst->pTransporter, &ep);
+    if (pMonitor == NULL){
+      continue;
     }
-    ppMonitor = taosHashIterate(monitorCounterHash, ppMonitor);
+    SAppInstInfo* pInst = getAppInstByClusterId(pMonitor->clusterId);
+    if(pInst == NULL){
+      taosHashCancelIterate(monitorCounterHash, ppMonitor);
+      break;
+    }
+    SEpSet ep = getEpSet_s(&pInst->mgmtEp);
+    generateClusterReport(pMonitor->registry, pInst->pTransporter, &ep);
   }
 }
 
@@ -330,7 +330,7 @@ static void monitorWriteSlowLog2File(MonitorSlowLogData* slowLogData, char *tmpP
     }
     taosGetTmpfilePath(tmpPath, clusterId, path);
     uInfo("[monitor] create slow log file:%s", path);
-    pFile = taosOpenFile(path, TD_FILE_CREATE | TD_FILE_WRITE | TD_FILE_APPEND | TD_FILE_READ | TD_FILE_TRUNC | TD_FILE_STREAM);
+    pFile = taosOpenFile(path, TD_FILE_CREATE | TD_FILE_WRITE | TD_FILE_APPEND | TD_FILE_READ | TD_FILE_TRUNC);
     if (pFile == NULL) {
       terrno = TAOS_SYSTEM_ERROR(errno);
       uError("failed to open file:%s since %s", path, terrstr());
@@ -378,63 +378,70 @@ static void monitorWriteSlowLog2File(MonitorSlowLogData* slowLogData, char *tmpP
   uDebug("[monitor] write slow log to file:%p, clusterId:%"PRIx64, pFile, slowLogData->clusterId);
 }
 
-static char* readFileByLine(TdFilePtr pFile, int64_t *offset, bool* isEnd){
+static char* readFile(TdFilePtr pFile, int64_t *offset, int64_t size){
   if(taosLSeekFile(pFile, *offset, SEEK_SET) < 0){
     uError("failed to seek file:%p code: %d", pFile, errno);
     return NULL;
   }
 
+  ASSERT(size > *offset);
+  char* pCont = NULL;
   int64_t totalSize = 0;
-  char* pCont = taosMemoryCalloc(1, SLOW_LOG_SEND_SIZE);
+  if (size - *offset >= SLOW_LOG_SEND_SIZE_MAX) {
+    pCont = taosMemoryCalloc(1, 2 * SLOW_LOG_SEND_SIZE_MAX);
+    totalSize = 2 * SLOW_LOG_SEND_SIZE_MAX;
+  }else{
+    pCont = taosMemoryCalloc(1, 2 * (size - *offset));
+    totalSize = 2 * (size - *offset);
+  }
+
   if(pCont == NULL){
+    uError("failed to allocate memory for slow log, size:%" PRId64, totalSize);
     return NULL;
   }
-  strcat(pCont, "[");
-
-  while(1) {
-    char*   pLine = NULL;
-    int64_t readLen = taosGetLineFile(pFile, &pLine);
-
-    if(totalSize + readLen >= SLOW_LOG_SEND_SIZE){
-      break;
+  char*  buf = pCont;
+  strcat(buf++, "[");
+  int64_t readSize = taosReadFile(pFile, buf, SLOW_LOG_SEND_SIZE_MAX);
+  if (readSize <= 0) {
+    if (readSize < 0){
+      uError("failed to read len from file:%p since %s", pFile, terrstr());
     }
-    if (readLen <= 0) {
-      if (readLen < 0) {
-        uError("failed to read len from file:%p since %s", pFile, terrstr());
-      }else if(totalSize == 0){
-        *isEnd = true;
-      }
-      break;
-    }
-
-    if (totalSize != 0) strcat(pCont, ",");
-    strcat(pCont, pLine);
-    totalSize += readLen;
-  }
-  strcat(pCont, "]");
-  uDebug("[monitor] monitorReadSendSlowLog slow log:%s", pCont);
-  *offset += totalSize;
-  if(*isEnd){
     taosMemoryFree(pCont);
     return NULL;
   }
+
+  totalSize = 0;
+  while(1){
+    size_t len = strlen(buf);
+    totalSize += (len+1);
+    if (totalSize > readSize || len == 0) {
+      *(buf-1) = ']';
+      *buf = '\0';
+      break;
+    }
+    buf[len] = ','; // replace '\0' with ','
+    buf += (len + 1);
+    *offset += (len+1);
+  }
+
+  uDebug("[monitor] monitorReadSendSlowLog slow log:%s", pCont);
   return pCont;
 }
 
-static bool isFileEmpty(char* path){
-  int64_t filesize = 0;
-  if (taosStatFile(path, &filesize, NULL, NULL) < 0) {
-    return false;
+static int64_t getFileSize(char* path){
+  int64_t fileSize = 0;
+  if (taosStatFile(path, &fileSize, NULL, NULL) < 0) {
+    return -1;
   }
 
-  if (filesize == 0) {
-    return true;
-  }
-  return false;
+  return fileSize;
 }
 
 static int32_t sendSlowLog(int64_t clusterId, char* data, TdFilePtr pFile, int64_t offset, SLOW_LOG_QUEUE_TYPE type, char* fileName, void* pTransporter, SEpSet *epSet){
   MonitorSlowLogData* pParam = taosMemoryMalloc(sizeof(MonitorSlowLogData));
+  if(pParam == NULL){
+    return -1;
+  }
   pParam->data = data;
   pParam->offset = offset;
   pParam->clusterId = clusterId;
@@ -445,15 +452,15 @@ static int32_t sendSlowLog(int64_t clusterId, char* data, TdFilePtr pFile, int64
 }
 
 static void monitorSendSlowLogAtBeginning(int64_t clusterId, char* fileName, TdFilePtr pFile, int64_t offset, void* pTransporter, SEpSet *epSet){
-  bool     isEnd = false;
-  char*    data = readFileByLine(pFile, &offset, &isEnd);
-  if(isEnd){
+  int64_t  size = getFileSize(fileName);
+  if(size <= offset){
     taosFtruncateFile(pFile, 0);
     taosUnLockFile(pFile);
     taosCloseFile(&pFile);
     taosRemoveFile(fileName);
     uDebug("[monitor] monitorSendSlowLogAtBeginning delete file:%s", fileName);
   }else{
+    char* data = readFile(pFile, &offset, size);
     if(data != NULL){
       sendSlowLog(clusterId, data, pFile, offset, SLOW_LOG_READ_BEGINNIG, taosStrdup(fileName), pTransporter, epSet);
     }
@@ -463,46 +470,61 @@ static void monitorSendSlowLogAtBeginning(int64_t clusterId, char* fileName, TdF
 
 static void monitorSendSlowLogAtRunning(int64_t clusterId){
   void* tmp = taosHashGet(monitorSlowLogHash, &clusterId, LONG_BYTES);
+  if (tmp == NULL){
+    return;
+  }
   SlowLogClient* pClient = (*(SlowLogClient**)tmp);
-  bool isEnd = false;
-  char* data = readFileByLine(pClient->pFile, &pClient->offset, &isEnd);
-  if(isEnd){
+  if (pClient == NULL){
+    return;
+  }
+  int64_t  size = getFileSize(pClient->path);
+  if(size <= pClient->offset){
     if(taosFtruncateFile(pClient->pFile, 0) < 0){
       uError("failed to truncate file:%p code: %d", pClient->pFile, errno);
     }
     pClient->offset = 0;
-  }else if(data != NULL){
+  }else{
     SAppInstInfo* pInst = getAppInstByClusterId(clusterId);
     if(pInst == NULL){
       uError("failed to get app instance by clusterId:%" PRId64, clusterId);
       return;
     }
     SEpSet ep = getEpSet_s(&pInst->mgmtEp);
-    sendSlowLog(clusterId, data, pClient->pFile, pClient->offset, SLOW_LOG_READ_RUNNING, NULL, pInst->pTransporter, &ep);
+    char* data = readFile(pClient->pFile, &pClient->offset, size);
+    if(data != NULL){
+      sendSlowLog(clusterId, data, pClient->pFile, pClient->offset, SLOW_LOG_READ_RUNNING, NULL, pInst->pTransporter, &ep);
+    }
     uDebug("[monitor] monitorReadSendSlowLog send slow log:%s", data);
   }
 }
 
 static bool monitorSendSlowLogAtQuit(int64_t clusterId) {
   void* tmp = taosHashGet(monitorSlowLogHash, &clusterId, LONG_BYTES);
+  if (tmp == NULL){
+    return true;
+  }
   SlowLogClient* pClient = (*(SlowLogClient**)tmp);
-
-  bool isEnd = false;
-  char* data = readFileByLine(pClient->pFile, &pClient->offset, &isEnd);
-  if(isEnd){
+  if (pClient == NULL){
+    return true;
+  }
+  int64_t size = getFileSize(pClient->path);
+  if(size <= pClient->offset){
     taosUnLockFile(pClient->pFile);
     taosCloseFile(&(pClient->pFile));
     taosRemoveFile(pClient->path);
     if((--quitCnt) == 0){
       return true;
     }
-  }else if(data != NULL){
+  }else{
     SAppInstInfo* pInst = getAppInstByClusterId(clusterId);
     if(pInst == NULL) {
       return true;
     }
     SEpSet ep = getEpSet_s(&pInst->mgmtEp);
-    sendSlowLog(clusterId, data, pClient->pFile, pClient->offset, SLOW_LOG_READ_QUIT, NULL, pInst->pTransporter, &ep);
+    char* data = readFile(pClient->pFile, &pClient->offset, size);
+    if(data != NULL){
+      sendSlowLog(clusterId, data, pClient->pFile, pClient->offset, SLOW_LOG_READ_QUIT, NULL, pInst->pTransporter, &ep);
+    }
     uDebug("[monitor] monitorReadSendSlowLog send slow log:%s", data);
   }
   return false;
@@ -510,14 +532,21 @@ static bool monitorSendSlowLogAtQuit(int64_t clusterId) {
 static void monitorSendAllSlowLogAtQuit(){
   void* pIter = NULL;
   while ((pIter = taosHashIterate(monitorSlowLogHash, pIter))) {
+    SlowLogClient* pClient = (*(SlowLogClient**)pIter);
+    if(pClient == NULL) {
+      taosHashCancelIterate(monitorSlowLogHash, pIter);
+      return;
+    }
     int64_t* clusterId = (int64_t*)taosHashGetKey(pIter, NULL);
     SAppInstInfo* pInst = getAppInstByClusterId(*clusterId);
-    if(pInst == NULL) return;
-    SlowLogClient* pClient = (*(SlowLogClient**)pIter);
+    if(pInst == NULL) {
+      taosHashCancelIterate(monitorSlowLogHash, pIter);
+      return;
+    }
     SEpSet ep = getEpSet_s(&pInst->mgmtEp);
-    bool isEnd = false;
     int64_t offset = 0;
-    char* data = readFileByLine(pClient->pFile, &offset, &isEnd);
+    int64_t size = getFileSize(pClient->path);
+    char* data = readFile(pClient->pFile, &offset, size);
     if(data != NULL && sendSlowLog(*clusterId, data, NULL, offset, SLOW_LOG_READ_QUIT, NULL, pInst->pTransporter, &ep) == 0){
       quitCnt ++;
     }
@@ -532,13 +561,20 @@ static void monitorSendAllSlowLog(){
     int64_t*       clusterId = (int64_t*)taosHashGetKey(pIter, NULL);
     SAppInstInfo*  pInst = getAppInstByClusterId(*clusterId);
     SlowLogClient* pClient = (*(SlowLogClient**)pIter);
+    if (pClient == NULL){
+      taosHashCancelIterate(monitorSlowLogHash, pIter);
+      return;
+    }
     if (pInst != NULL && t - pClient->lastCheckTime > pInst->monitorParas.tsMonitorInterval * 1000 &&
-        pClient->offset == 0 && !isFileEmpty(pClient->path)) {
+        pClient->offset == 0) {
+      int64_t size = getFileSize(pClient->path);
+      if(size <= 0){
+        continue;
+      }
       pClient->lastCheckTime = t;
       SEpSet ep = getEpSet_s(&pInst->mgmtEp);
-      bool isEnd = false;
       int64_t offset = 0;
-      char* data = readFileByLine(pClient->pFile, &offset, &isEnd);
+      char* data = readFile(pClient->pFile, &offset, size);
       if(data != NULL){
         sendSlowLog(*clusterId, data, NULL, offset, SLOW_LOG_READ_RUNNING, NULL, pInst->pTransporter, &ep);
       }
@@ -586,7 +622,7 @@ static void monitorSendAllSlowLogFromTempDir(int64_t clusterId){
 
     char filename[PATH_MAX] = {0};
     snprintf(filename, sizeof(filename), "%s%s", tmpPath, name);
-    TdFilePtr pFile = taosOpenFile(filename, TD_FILE_READ | TD_FILE_STREAM | TD_FILE_TRUNC);
+    TdFilePtr pFile = taosOpenFile(filename, TD_FILE_READ | TD_FILE_TRUNC);
     if (pFile == NULL) {
       uError("failed to open file:%s since %s", filename, terrstr());
       continue;
diff --git a/source/client/test/clientMonitorTests.cpp b/source/client/test/clientMonitorTests.cpp
index 2d3ce87f38..6285be5a4c 100644
--- a/source/client/test/clientMonitorTests.cpp
+++ b/source/client/test/clientMonitorTests.cpp
@@ -64,6 +64,65 @@ int main(int argc, char** argv) {
 //  clusterMonitorClose(cluster2);
 //}
 
+static char* readFile(TdFilePtr pFile, int64_t *offset, int64_t size){
+  if(taosLSeekFile(pFile, *offset, SEEK_SET) < 0){
+    uError("failed to seek file:%p code: %d", pFile, errno);
+    return NULL;
+  }
+
+  ASSERT(size > *offset);
+  char* pCont = NULL;
+  int64_t totalSize = 0;
+  if (size - *offset >= SLOW_LOG_SEND_SIZE_MAX) {
+    pCont = (char*)taosMemoryCalloc(1, 2 * SLOW_LOG_SEND_SIZE_MAX);
+    totalSize = 2 * SLOW_LOG_SEND_SIZE_MAX;
+  }else{
+    pCont = (char*)taosMemoryCalloc(1, 2 * (size - *offset));
+    totalSize = 2 * (size - *offset);
+  }
+
+  if(pCont == NULL){
+    uError("failed to allocate memory for slow log, size:%" PRId64, totalSize);
+    return NULL;
+  }
+  char*  buf = pCont;
+  strcat(buf++, "[");
+  int64_t readSize = taosReadFile(pFile, buf, SLOW_LOG_SEND_SIZE_MAX);
+  if (readSize <= 0) {
+    if (readSize < 0){
+      uError("failed to read len from file:%p since %s", pFile, terrstr());
+    }
+    taosMemoryFree(pCont);
+    return NULL;
+  }
+
+  totalSize = 0;
+  while(1){
+    size_t len = strlen(buf);
+    totalSize += (len+1);
+    if (totalSize > readSize || len == 0) {
+      *(buf-1) = ']';
+      *buf = '\0';
+      break;
+    }
+    buf[len] = ','; // replace '\0' with ','
+    buf += (len + 1);
+    *offset += (len+1);
+  }
+
+  uDebug("[monitor] monitorReadSendSlowLog slow log:%s", pCont);
+  return pCont;
+}
+
+static int64_t getFileSize(char* path){
+  int64_t fileSize = 0;
+  if (taosStatFile(path, &fileSize, NULL, NULL) < 0) {
+    return -1;
+  }
+
+  return fileSize;
+}
+
 TEST(clientMonitorTest, sendTest) {
   TAOS*       taos = taos_connect("127.0.0.1", "root", "taosdata", NULL, 0);
   ASSERT_TRUE(taos != NULL);
@@ -91,8 +150,8 @@ TEST(clientMonitorTest, ReadOneFile) {
   }
 
   const int batch = 10;
-  const int size = SLOW_LOG_SEND_SIZE/batch;
-  for(int i = 0; i < batch + 1; i++){
+  const int size = 10;
+  for(int i = 0; i < batch; i++){
     char value[size] = {0};
     memset(value, '0' + i, size - 1);
     if (taosWriteFile(pFile, value, strlen(value) + 1) < 0){
@@ -106,64 +165,72 @@ TEST(clientMonitorTest, ReadOneFile) {
   // Create an SEpSet object and set it up for testing
   SEpSet* epSet = NULL;
 
+  int64_t  fileSize = getFileSize("./tdengine-1-wewe");
   // Call the function to be tested
-//  monitorReadSendSlowLog(pFile, (int64_t)pTransporter, epSet);
-
-  char value[size] = {0};
-  memset(value, '0', size - 1);
-  if (taosWriteFile(pFile, value, strlen(value) + 1) < 0){
-    uError("failed to write len to file:%p since %s", pFile, terrstr());
+  int64_t offset = 0;
+  while(1){
+    if (offset >= fileSize) {
+      break;
+    }
+    char* val = readFile(pFile, &offset, fileSize);
+    printf("offset:%" PRId64",fileSize:%"PRId64",val:%s\n", offset, fileSize, val);
   }
 
+//  char value[size] = {0};
+//  memset(value, '0', size - 1);
+//  if (taosWriteFile(pFile, value, strlen(value) + 1) < 0){
+//    uError("failed to write len to file:%p since %s", pFile, terrstr());
+//  }
+
 //  monitorReadSendSlowLog(pFile, (int64_t)pTransporter, epSet);
 
   // Clean up any resources created for testing
   taosCloseFile(&pFile);
 }
 
-TEST(clientMonitorTest, ReadTwoFile) {
-  // Create a TdFilePtr object and set it up for testing
-
-  TdFilePtr pFile = taosOpenFile("/tmp/tdengine_slow_log/tdengine-1-wewe", TD_FILE_CREATE | TD_FILE_WRITE | TD_FILE_APPEND | TD_FILE_READ | TD_FILE_TRUNC);
-  if (pFile == NULL) {
-    uError("failed to open file:./test.txt since %s", terrstr());
-    return;
-  }
-
-  const int batch = 10;
-  const int size = SLOW_LOG_SEND_SIZE/batch;
-  for(int i = 0; i < batch + 1; i++){
-    char value[size] = {0};
-    memset(value, '0' + i, size - 1);
-    if (taosWriteFile(pFile, value, strlen(value) + 1) < 0){
-      uError("failed to write len to file:%p since %s", pFile, terrstr());
-    }
-  }
-
-  taosFsyncFile(pFile);
-  taosCloseFile(&pFile);
-
-  pFile = taosOpenFile("/tmp/tdengine_slow_log/tdengine-2-wewe", TD_FILE_CREATE | TD_FILE_WRITE | TD_FILE_APPEND | TD_FILE_READ | TD_FILE_TRUNC);
-  if (pFile == NULL) {
-    uError("failed to open file:./test.txt since %s", terrstr());
-    return;
-  }
-
-  for(int i = 0; i < batch + 1; i++){
-    char value[size] = {0};
-    memset(value, '0' + i, size - 1);
-    if (taosWriteFile(pFile, value, strlen(value) + 1) < 0){
-      uError("failed to write len to file:%p since %s", pFile, terrstr());
-    }
-  }
-
-  taosFsyncFile(pFile);
-  taosCloseFile(&pFile);
-
-  SAppInstInfo pAppInfo = {0};
-  pAppInfo.clusterId = 2;
-  pAppInfo.monitorParas.tsEnableMonitor = 1;
-  strcpy(tsTempDir,"/tmp");
-//  monitorSendAllSlowLogFromTempDir(&pAppInfo);
-
-}
\ No newline at end of file
+//TEST(clientMonitorTest, ReadTwoFile) {
+//  // Create a TdFilePtr object and set it up for testing
+//
+//  TdFilePtr pFile = taosOpenFile("/tmp/tdengine_slow_log/tdengine-1-wewe", TD_FILE_CREATE | TD_FILE_WRITE | TD_FILE_APPEND | TD_FILE_READ | TD_FILE_TRUNC);
+//  if (pFile == NULL) {
+//    uError("failed to open file:./test.txt since %s", terrstr());
+//    return;
+//  }
+//
+//  const int batch = 10;
+//  const int size = SLOW_LOG_SEND_SIZE/batch;
+//  for(int i = 0; i < batch + 1; i++){
+//    char value[size] = {0};
+//    memset(value, '0' + i, size - 1);
+//    if (taosWriteFile(pFile, value, strlen(value) + 1) < 0){
+//      uError("failed to write len to file:%p since %s", pFile, terrstr());
+//    }
+//  }
+//
+//  taosFsyncFile(pFile);
+//  taosCloseFile(&pFile);
+//
+//  pFile = taosOpenFile("/tmp/tdengine_slow_log/tdengine-2-wewe", TD_FILE_CREATE | TD_FILE_WRITE | TD_FILE_APPEND | TD_FILE_READ | TD_FILE_TRUNC);
+//  if (pFile == NULL) {
+//    uError("failed to open file:./test.txt since %s", terrstr());
+//    return;
+//  }
+//
+//  for(int i = 0; i < batch + 1; i++){
+//    char value[size] = {0};
+//    memset(value, '0' + i, size - 1);
+//    if (taosWriteFile(pFile, value, strlen(value) + 1) < 0){
+//      uError("failed to write len to file:%p since %s", pFile, terrstr());
+//    }
+//  }
+//
+//  taosFsyncFile(pFile);
+//  taosCloseFile(&pFile);
+//
+//  SAppInstInfo pAppInfo = {0};
+//  pAppInfo.clusterId = 2;
+//  pAppInfo.monitorParas.tsEnableMonitor = 1;
+//  strcpy(tsTempDir,"/tmp");
+////  monitorSendAllSlowLogFromTempDir(&pAppInfo);
+//
+//}
\ No newline at end of file