diff --git a/src/common/src/tglobal.c b/src/common/src/tglobal.c
index f51d205c26..80bf48364c 100644
--- a/src/common/src/tglobal.c
+++ b/src/common/src/tglobal.c
@@ -47,7 +47,7 @@ char     tsEmail[TSDB_FQDN_LEN] = {0};
 // common
 int32_t tsRpcTimer       = 1000;
 int32_t tsRpcMaxTime     = 600;  // seconds;
-int32_t tsMaxShellConns  = 5000;
+int32_t tsMaxShellConns  = 50000;
 int32_t tsMaxConnections = 5000;
 int32_t tsShellActivityTimer  = 3;  // second
 float   tsNumOfThreadsPerCore = 1.0f;
diff --git a/src/kit/shell/inc/shell.h b/src/kit/shell/inc/shell.h
index 3702a7d02d..50bceb1a71 100644
--- a/src/kit/shell/inc/shell.h
+++ b/src/kit/shell/inc/shell.h
@@ -64,7 +64,7 @@ extern TAOS* shellInit(SShellArguments* args);
 extern void* shellLoopQuery(void* arg);
 extern void taos_error(TAOS_RES* tres, int64_t st);
 extern int regex_match(const char* s, const char* reg, int cflags);
-void shellReadCommand(TAOS* con, char command[]);
+int32_t shellReadCommand(TAOS* con, char command[]);
 int32_t shellRunCommand(TAOS* con, char* command);
 void shellRunCommandOnServer(TAOS* con, char command[]);
 void read_history();
diff --git a/src/kit/shell/src/shellDarwin.c b/src/kit/shell/src/shellDarwin.c
index dbec3fdb05..31ad7046e9 100644
--- a/src/kit/shell/src/shellDarwin.c
+++ b/src/kit/shell/src/shellDarwin.c
@@ -180,7 +180,7 @@ void shellParseArgument(int argc, char *argv[], SShellArguments *arguments) {
   }
 }
 
-void shellReadCommand(TAOS *con, char *command) {
+int32_t shellReadCommand(TAOS *con, char *command) {
   unsigned hist_counter = history.hend;
   char utf8_array[10] = "\0";
   Command cmd;
@@ -233,7 +233,7 @@ void shellReadCommand(TAOS *con, char *command) {
             sprintf(command, "%s%s", cmd.buffer, cmd.command);
             tfree(cmd.buffer);
             tfree(cmd.command);
-            return;
+            return 0;
           } else {
             updateBuffer(&cmd);
           }
@@ -324,6 +324,8 @@ void shellReadCommand(TAOS *con, char *command) {
       insertChar(&cmd, &c, 1);
     }
   }
+
+  return 0;
 }
 
 void *shellLoopQuery(void *arg) {
@@ -342,11 +344,16 @@ void *shellLoopQuery(void *arg) {
       return NULL;
     }
 
+    int32_t err = 0;
+
     do {
       // Read command from shell.
       memset(command, 0, MAX_COMMAND_SIZE);
       set_terminal_mode();
-      shellReadCommand(con, command);
+      err = shellReadCommand(con, command);
+      if (err) {
+        break;
+      }
       reset_terminal_mode();
     } while (shellRunCommand(con, command) == 0);
 
diff --git a/src/kit/shell/src/shellLinux.c b/src/kit/shell/src/shellLinux.c
index a8f457377d..07b21531a7 100644
--- a/src/kit/shell/src/shellLinux.c
+++ b/src/kit/shell/src/shellLinux.c
@@ -172,7 +172,7 @@ void shellParseArgument(int argc, char *argv[], SShellArguments *arguments) {
   }
 }
 
-void shellReadCommand(TAOS *con, char *command) {
+int32_t shellReadCommand(TAOS *con, char *command) {
   unsigned hist_counter = history.hend;
   char utf8_array[10] = "\0";
   Command cmd;
@@ -186,6 +186,10 @@ void shellReadCommand(TAOS *con, char *command) {
   while (1) {
     c = (char)getchar(); // getchar() return an 'int' value
 
+    if (c == EOF) {
+      return c;
+    }
+
     if (c < 0) {  // For UTF-8
       int count = countPrefixOnes(c);
       utf8_array[0] = c;
@@ -225,7 +229,7 @@ void shellReadCommand(TAOS *con, char *command) {
             sprintf(command, "%s%s", cmd.buffer, cmd.command);
             tfree(cmd.buffer);
             tfree(cmd.command);
-            return;
+            return 0;
           } else {
             updateBuffer(&cmd);
           }
@@ -316,6 +320,8 @@ void shellReadCommand(TAOS *con, char *command) {
       insertChar(&cmd, &c, 1);
     }
   }
+
+  return 0;
 }
 
 void *shellLoopQuery(void *arg) {
@@ -333,12 +339,17 @@ void *shellLoopQuery(void *arg) {
     uError("failed to malloc command");
     return NULL;
   }
+
+  int32_t err = 0;
   
   do {
     // Read command from shell.
     memset(command, 0, MAX_COMMAND_SIZE);
     set_terminal_mode();
-    shellReadCommand(con, command);
+    err = shellReadCommand(con, command);
+    if (err) {
+      break;
+    }
     reset_terminal_mode();
   } while (shellRunCommand(con, command) == 0);
   
diff --git a/src/kit/shell/src/shellWindows.c b/src/kit/shell/src/shellWindows.c
index 56021d9c34..11c1ac34d8 100644
--- a/src/kit/shell/src/shellWindows.c
+++ b/src/kit/shell/src/shellWindows.c
@@ -221,7 +221,7 @@ void insertChar(Command *cmd, char c) {
   cmd->command[cmd->cursorOffset++] = c;
 }
 
-void shellReadCommand(TAOS *con, char command[]) {
+int32_t shellReadCommand(TAOS *con, char command[]) {
   Command cmd;
   memset(&cmd, 0, sizeof(cmd));
   cmd.buffer = (char *)calloc(1, MAX_COMMAND_SIZE);
@@ -241,7 +241,7 @@ void shellReadCommand(TAOS *con, char command[]) {
           cmd.buffer = NULL;
           free(cmd.command);
           cmd.command = NULL;
-          return;
+          return 0;
         } else {
           shellPrintContinuePrompt();
           updateBuffer(&cmd);
@@ -251,6 +251,8 @@ void shellReadCommand(TAOS *con, char command[]) {
         insertChar(&cmd, c);
     }
   }
+
+  return 0;
 }
 
 void *shellLoopQuery(void *arg) {
@@ -258,12 +260,17 @@ void *shellLoopQuery(void *arg) {
   char *command = malloc(MAX_COMMAND_SIZE);
   if (command == NULL) return NULL;
 
+  int32_t err = 0;
+  
   do {
     memset(command, 0, MAX_COMMAND_SIZE);
     shellPrintPrompt();
 
     // Read command from shell.
-    shellReadCommand(con, command);
+    err = shellReadCommand(con, command);
+    if (err) {
+      break;
+    }    
   } while (shellRunCommand(con, command) == 0);
 
   return NULL;
diff --git a/src/query/src/qAggMain.c b/src/query/src/qAggMain.c
index 1e97729079..feea4707bc 100644
--- a/src/query/src/qAggMain.c
+++ b/src/query/src/qAggMain.c
@@ -92,8 +92,9 @@ typedef struct SSpreadInfo {
 
 typedef struct SSumInfo {
   union {
-    int64_t isum;
-    double  dsum;
+    int64_t  isum;
+    uint64_t usum;
+    double   dsum;
   };
   int8_t hasResult;
 } SSumInfo;
@@ -595,6 +596,18 @@ static void do_sum_f(SQLFunctionCtx *pCtx, int32_t index) {
     *res += GET_INT32_VAL(pData);
   } else if (pCtx->inputType == TSDB_DATA_TYPE_BIGINT) {
     *res += GET_INT64_VAL(pData);
+  } else if (pCtx->inputType == TSDB_DATA_TYPE_UTINYINT) {
+    uint64_t *r = (uint64_t *)pCtx->pOutput;
+    *r += GET_UINT8_VAL(pData);
+  } else if (pCtx->inputType == TSDB_DATA_TYPE_USMALLINT) {
+    uint64_t *r = (uint64_t *)pCtx->pOutput;
+    *r += GET_UINT16_VAL(pData);
+  } else if (pCtx->inputType == TSDB_DATA_TYPE_UINT) {
+    uint64_t *r = (uint64_t *)pCtx->pOutput;
+    *r += GET_UINT32_VAL(pData);
+  } else if (pCtx->inputType == TSDB_DATA_TYPE_UBIGINT) {
+    uint64_t *r = (uint64_t *)pCtx->pOutput;
+    *r += GET_UINT64_VAL(pData);
   } else if (pCtx->inputType == TSDB_DATA_TYPE_DOUBLE) {
     double *retVal = (double*) pCtx->pOutput;
     *retVal += GET_DOUBLE_VAL(pData);
@@ -644,18 +657,12 @@ static void sum_func_merge(SQLFunctionCtx *pCtx) {
 
     notNullElems++;
 
-    switch (type) {
-      case TSDB_DATA_TYPE_TINYINT:
-      case TSDB_DATA_TYPE_SMALLINT:
-      case TSDB_DATA_TYPE_INT:
-      case TSDB_DATA_TYPE_BIGINT: {
-        *(int64_t *)pCtx->pOutput += pInput->isum;
-        break;
-      };
-      case TSDB_DATA_TYPE_FLOAT:
-      case TSDB_DATA_TYPE_DOUBLE: {
-        *(double *)pCtx->pOutput += pInput->dsum;
-      }
+    if (IS_SIGNED_NUMERIC_TYPE(type)) {
+      *(int64_t *)pCtx->pOutput += pInput->isum;
+    } else if (IS_UNSIGNED_NUMERIC_TYPE(type)) {
+      *(uint64_t *) pCtx->pOutput += pInput->usum;
+    } else {
+      *(double *)pCtx->pOutput += pInput->dsum;
     }
   }