diff --git a/documentation20/webdocs/markdowndocs/architecture-ch.md b/documentation20/webdocs/markdowndocs/architecture-ch.md
index bfe3b55bd22fa9ec44e9305ed0924ef110ff7b15..7ab4b5d096b4676b205fa57175889f780df2cb45 100644
--- a/documentation20/webdocs/markdowndocs/architecture-ch.md
+++ b/documentation20/webdocs/markdowndocs/architecture-ch.md
@@ -82,7 +82,7 @@ TDengine 分布式架构的逻辑结构图如下：
 ### 节点之间的通讯
 **通讯方式：**TDengine系统的各个节点之间的通讯是通过TCP/UDP进行的。因为考虑到物联网场景，数据写入的包一般不大，因此TDengine 除采用TCP做传输之外，还采用UDP方式，因为UDP 更加高效，而且不受连接数的限制。TDengine实现了自己的超时、重传、确认等机制，以确保UDP的可靠传输。对于数据量不到15K的数据包，采取UDP的方式进行传输，超过15K的，或者是查询类的操作，自动采取TCP的方式进行传输。同时，TDengine根据配置和数据包，会自动对数据进行压缩/解压缩，数字签名/认证等处理。对于数据节点之间的数据复制，只采用TCP方式进行数据传输。
 
-**FQDN配置**：一个数据节点有一个或多个FQDN，可以在系统配置文件taos.cfg通过选项“fqdn"进行指定，如果没有指定，系统将自动获取FQDN。如果节点没有配置FQDN，可以直接使用IP地址作为FQDN，但不建议使用，因为IP地址可变，一旦变化，将让集群无法正常工作。一个数据节点的EP(End Point)由FQDN + Port组成。
+**FQDN配置**：一个数据节点有一个或多个FQDN，可以在系统配置文件taos.cfg通过参数“fqdn"进行指定，如果没有指定，系统将自动获取FQDN。如果节点没有配置FQDN，可以直接将该节点的配置参数fqdn设置为它的IP地址。但不建议使用IP，因为IP地址可变，一旦变化，将让集群无法正常工作。一个数据节点的EP(End Point)由FQDN + Port组成。采用FQDN，需要保证DNS服务正常工作，或者在节点以及应用所在的节点配置好hosts文件。
 
 **端口配置：**一个数据节点对外的端口由TDengine的系统配置参数serverPort决定，对集群内部通讯的端口是serverPort+5。集群内数据节点之间的数据复制操作还占有一个TCP端口，是serverPort+10. 为支持多线程高效的处理UDP数据，每个对内和对外的UDP链接，都需要占用5个连续的端口。因此一个数据节点总的端口范围为serverPort到serverPort + 10，总共11个TCP/UDP端口。使用时，需要确保防火墙将这些端口打开。每个数据节点可以配置不同的serverPort。
 
diff --git a/packaging/tools/install.sh b/packaging/tools/install.sh
index f38677f7acd683125f25a5d7e26ec3a8a84c66ae..1cbb3ead9cee61c44f4b311f730f8f23458e72af 100755
--- a/packaging/tools/install.sh
+++ b/packaging/tools/install.sh
@@ -705,6 +705,7 @@ function install_TDengine() {
         echo
         echo -e "\033[44;32;1mTDengine client is installed successfully!${NC}"
     fi
+    touch ~/.taos_history
 
     rm -rf $(tar -tf taos.tar.gz)
 }
diff --git a/src/client/src/tscProfile.c b/src/client/src/tscProfile.c
index f48e7b7691536cb8f9a5b8561e95b8a5a0f0fefc..6ff97e9d00ad9cbf8cd6fdc92713b111a497c321 100644
--- a/src/client/src/tscProfile.c
+++ b/src/client/src/tscProfile.c
@@ -285,9 +285,9 @@ void tscKillConnection(STscObj *pObj) {
 
   SSqlObj *pSql = pObj->sqlList;
   while (pSql) {
-    //taosStopRpcConn(pSql->thandle);
     pSql = pSql->next;
   }
+  
 
   SSqlStream *pStream = pObj->streamList;
   while (pStream) {
diff --git a/src/client/src/tscServer.c b/src/client/src/tscServer.c
index 9282fa74fbab3e32f8332b69d3800d84c37e5dd6..4f179adf72320c971dc74ccf28b12f4d022a17fc 100644
--- a/src/client/src/tscServer.c
+++ b/src/client/src/tscServer.c
@@ -226,13 +226,17 @@ int tscSendMsgToServer(SSqlObj *pSql) {
       .handle  = &pSql->pRpcCtx,
       .code    = 0
   };
-
   // NOTE: the rpc context should be acquired before sending data to server.
   // Otherwise, the pSql object may have been released already during the response function, which is
   // processMsgFromServer function. In the meanwhile, the assignment of the rpc context to sql object will absolutely
   // cause crash.
-  rpcSendRequest(pObj->pDnodeConn, &pSql->epSet, &rpcMsg);
-  return TSDB_CODE_SUCCESS;
+  if (pObj != NULL && pObj->signature == pObj) {
+    rpcSendRequest(pObj->pDnodeConn, &pSql->epSet, &rpcMsg);
+    return TSDB_CODE_SUCCESS;
+  } else {
+    //pObj->signature has been reset by other thread, ignore concurrency problem
+    return TSDB_CODE_TSC_CONN_KILLED; 
+  }
 }
 
 void tscProcessMsgFromServer(SRpcMsg *rpcMsg, SRpcEpSet *pEpSet) {
diff --git a/src/dnode/src/dnodeSystem.c b/src/dnode/src/dnodeSystem.c
index 6f32bc0f7ad3e7a5e1704cc24cf54ac62dbfd694..56316e9619344243ab2e5fa46e0acfc6e0331e8a 100644
--- a/src/dnode/src/dnodeSystem.c
+++ b/src/dnode/src/dnodeSystem.c
@@ -119,11 +119,8 @@ int32_t main(int32_t argc, char *argv[]) {
 
   syslog(LOG_INFO, "Started TDengine service successfully.");
 
-  for (int res = tsem_wait(&exitSem); res != 0; res = tsem_wait(&exitSem)) {
-    if (res != EINTR) {
-      syslog(LOG_ERR, "failed to wait exit semphore: %d", res);
-      break;
-    }
+  if (tsem_wait(&exitSem) != 0) {
+    syslog(LOG_ERR, "failed to wait exit semphore: %s", strerror(errno));
   }
 
   dnodeCleanUpSystem();
diff --git a/src/inc/taoserror.h b/src/inc/taoserror.h
index df69d1d19a8910622565dc1ebfd6a4829b79de7b..e7c3d5e4cce154b84c03dadc3f4f0a7c7f1ac69d 100644
--- a/src/inc/taoserror.h
+++ b/src/inc/taoserror.h
@@ -97,6 +97,7 @@ TAOS_DEFINE_ERROR(TSDB_CODE_TSC_APP_ERROR,                0, 0x0211, "Applicatio
 TAOS_DEFINE_ERROR(TSDB_CODE_TSC_ACTION_IN_PROGRESS,       0, 0x0212, "Action in progress")
 TAOS_DEFINE_ERROR(TSDB_CODE_TSC_DISCONNECTED,             0, 0x0213, "Disconnected from service")
 TAOS_DEFINE_ERROR(TSDB_CODE_TSC_NO_WRITE_AUTH,            0, 0x0214, "No write permission")
+TAOS_DEFINE_ERROR(TSDB_CODE_TSC_CONN_KILLED,            0, 0x0215, "Connection killed")
 
 // mnode
 TAOS_DEFINE_ERROR(TSDB_CODE_MND_MSG_NOT_PROCESSED,        0, 0x0300, "Message not processed")
diff --git a/src/mnode/src/mnodeProfile.c b/src/mnode/src/mnodeProfile.c
index 34147f2e4b3599c5b8357ba510eaab967352c007..06f992c26a4b2fd6eec19abb9743e4add2536000 100644
--- a/src/mnode/src/mnodeProfile.c
+++ b/src/mnode/src/mnodeProfile.c
@@ -100,7 +100,7 @@ SConnObj *mnodeCreateConn(char *user, uint32_t ip, uint16_t port) {
   };
   tstrncpy(connObj.user, user, sizeof(connObj.user));
   
-  SConnObj *pConn = taosCachePut(tsMnodeConnCache, &connId, sizeof(int32_t), &connObj, sizeof(connObj), CONN_KEEP_TIME*1000);
+  SConnObj *pConn = taosCachePut(tsMnodeConnCache, &connId, sizeof(int32_t), &connObj, sizeof(connObj), CONN_KEEP_TIME * 1000);
 
   mDebug("connId:%d, is created, user:%s ip:%s:%u", connId, user, taosIpStr(ip), port);
   return pConn;
diff --git a/src/os/inc/osSemphone.h b/src/os/inc/osSemphone.h
index fd88d2d7981a4e0f9dc397e73bf242eb7e059cf7..4280b458a65b23b3aa680c6ed46f61beb5c48948 100644
--- a/src/os/inc/osSemphone.h
+++ b/src/os/inc/osSemphone.h
@@ -23,7 +23,7 @@ extern "C" {
 #ifndef TAOS_OS_FUNC_SEMPHONE
   #define tsem_t sem_t
   #define tsem_init sem_init
-  #define tsem_wait sem_wait
+  int tsem_wait(tsem_t* sem);
   #define tsem_post sem_post
   #define tsem_destroy sem_destroy
 #endif
diff --git a/src/os/src/detail/osSemphone.c b/src/os/src/detail/osSemphone.c
index 74f8859029f95c67a2f298a0dbfa983978b4b78f..b91888845edd9e98315994eaada9eca245aacb24 100644
--- a/src/os/src/detail/osSemphone.c
+++ b/src/os/src/detail/osSemphone.c
@@ -16,6 +16,18 @@
 #define _DEFAULT_SOURCE
 #include "os.h"
 
+#ifndef TAOS_OS_FUNC_SEMPHONE
+
+int tsem_wait(tsem_t* sem) {
+  int ret = 0;
+  do {
+    ret = sem_wait(sem);
+  } while (ret != 0 && errno == EINTR);
+  return ret;
+}
+
+#endif
+
 #ifndef TAOS_OS_FUNC_SEMPHONE_PTHREAD
 
 bool    taosCheckPthreadValid(pthread_t thread) { return thread != 0; }
diff --git a/src/sync/src/tarbitrator.c b/src/sync/src/tarbitrator.c
index 4e55cc475f0b48f9786debf75532af16a48db787..40438ab1d2172583ace9d12f08b774b39c1b0bfe 100644
--- a/src/sync/src/tarbitrator.c
+++ b/src/sync/src/tarbitrator.c
@@ -99,9 +99,7 @@ int main(int argc, char *argv[]) {
 
   sInfo("TAOS arbitrator: %s:%d is running", tsNodeFqdn, tsArbitratorPort);
 
-  for (int res = tsem_wait(&tsArbSem); res != 0; res = tsem_wait(&tsArbSem)) {
-    if (res != EINTR) break;
-  }
+  tsem_wait(&tsArbSem);
 
   taosCloseTcpThreadPool(tsArbTcpPool);
   sInfo("TAOS arbitrator is shut down\n");
diff --git a/src/util/src/tsched.c b/src/util/src/tsched.c
index cf7f5c10d4c369211baddcf43e1ec0d10fea82b1..f014dd0fab5494bd85f197e2c79fac53359e8edf 100644
--- a/src/util/src/tsched.c
+++ b/src/util/src/tsched.c
@@ -123,11 +123,6 @@ void *taosProcessSchedQueue(void *param) {
 
   while (1) {
     if (tsem_wait(&pSched->fullSem) != 0) {
-      if (errno == EINTR) {
-        /* sem_wait is interrupted by interrupt, ignore and continue */
-        uDebug("wait %s fullSem was interrupted", pSched->label);
-        continue;
-      }
       uError("wait %s fullSem failed(%s)", pSched->label, strerror(errno));
     }
     if (pSched->stop) {
@@ -163,12 +158,8 @@ int taosScheduleTask(void *qhandle, SSchedMsg *pMsg) {
     return 0;
   }
 
-  while (tsem_wait(&pSched->emptySem) != 0) {
-    if (errno != EINTR) {
-      uError("wait %s emptySem failed(%s)", pSched->label, strerror(errno));
-      break;
-    }
-    uDebug("wait %s emptySem was interrupted", pSched->label);
+  if (tsem_wait(&pSched->emptySem) != 0) {
+    uError("wait %s emptySem failed(%s)", pSched->label, strerror(errno));
   }
 
   if (pthread_mutex_lock(&pSched->queueMutex) != 0)