diff --git a/include/libs/sync/sync.h b/include/libs/sync/sync.h
index 790cbf906da887c01bec011a875a67db8f359b7b..e6a4dd1d493969a333005a64f515ba35dde34573 100644
--- a/include/libs/sync/sync.h
+++ b/include/libs/sync/sync.h
@@ -33,7 +33,7 @@ extern bool gRaftDetailLog;
 #define SYNC_MAX_READ_RANGE          2
 #define SYNC_MAX_PROGRESS_WAIT_MS    4000
 #define SYNC_MAX_START_TIME_RANGE_MS (1000 * 20)
-#define SYNC_MAX_RECV_TIME_RANGE_MS  1000
+#define SYNC_MAX_RECV_TIME_RANGE_MS  1200
 #define SYNC_ADD_QUORUM_COUNT        3
 
 #define SYNC_MAX_BATCH_SIZE 1
diff --git a/source/libs/transport/inc/transComm.h b/source/libs/transport/inc/transComm.h
index 6b52c7427177bdd1662db63d57308e231348e99b..bc1c6386f6e0d9a61b21e5ca0e3aa198c1da043e 100644
--- a/source/libs/transport/inc/transComm.h
+++ b/source/libs/transport/inc/transComm.h
@@ -98,6 +98,11 @@ typedef void* queue[2];
 #define TRANS_RETRY_INTERVAL    15    // retry interval (ms)
 #define TRANS_CONN_TIMEOUT      3     // connect timeout (s)
 #define TRANS_READ_TIMEOUT      3000  // read timeout  (ms)
+#define TRANS_PACKET_LIMIT      1024 * 1024 * 512
+
+#define TRANS_MAGIC_NUM 0x5f375a86
+
+#define TRANS_NOVALID_PACKET(src) ((src) != TRANS_MAGIC_NUM ? 1 : 0)
 
 typedef SRpcMsg      STransMsg;
 typedef SRpcCtx      STransCtx;
@@ -151,6 +156,7 @@ typedef struct {
   char hasEpSet : 2;  // contain epset or not, 0(default): no epset, 1: contain epset
 
   char     user[TSDB_UNI_LEN];
+  uint32_t magicNum;
   STraceId traceId;
   uint64_t ahandle;  // ahandle assigned by client
   uint32_t code;     // del later
@@ -203,6 +209,7 @@ typedef struct SConnBuffer {
   int   cap;
   int   left;
   int   total;
+  int   invalid;
 } SConnBuffer;
 
 typedef void (*AsyncCB)(uv_async_t* handle);
diff --git a/source/libs/transport/src/thttp.c b/source/libs/transport/src/thttp.c
index 62277a7569a836f84e2ea143dc648737c208b3c8..dc0f9128b0540ee96637de619017c4a67c335659 100644
--- a/source/libs/transport/src/thttp.c
+++ b/source/libs/transport/src/thttp.c
@@ -221,7 +221,6 @@ int32_t taosSendHttpReport(const char* server, uint16_t port, char* pCont, int32
     uError("failed to receive response from %s:%u since %s", server, port, terrstr());
     goto SEND_OVER;
   }
-
   code = 0;
 
 SEND_OVER:
diff --git a/source/libs/transport/src/transCli.c b/source/libs/transport/src/transCli.c
index add007e14d2a49a18bb2be13deb17430eb8841c6..8fdfcd5309c927e4e49386340fbd44496a4a7688 100644
--- a/source/libs/transport/src/transCli.c
+++ b/source/libs/transport/src/transCli.c
@@ -759,6 +759,7 @@ void cliSend(SCliConn* pConn) {
   pHead->release = REQUEST_RELEASE_HANDLE(pCliMsg) ? 1 : 0;
   memcpy(pHead->user, pTransInst->user, strlen(pTransInst->user));
   pHead->traceId = pMsg->info.traceId;
+  pHead->magicNum = htonl(TRANS_MAGIC_NUM);
 
   uv_buf_t wb = uv_buf_init((char*)pHead, msgLen);
 
diff --git a/source/libs/transport/src/transComm.c b/source/libs/transport/src/transComm.c
index 4272ec0b1c201d930e4c63c9266312a77bef97bd..3ba8186e9dbebb52260eeb24766de603f957a9e3 100644
--- a/source/libs/transport/src/transComm.c
+++ b/source/libs/transport/src/transComm.c
@@ -91,6 +91,7 @@ int transInitBuffer(SConnBuffer* buf) {
   buf->left = -1;
   buf->len = 0;
   buf->total = 0;
+  buf->invalid = 0;
   return 0;
 }
 int transDestroyBuffer(SConnBuffer* p) {
@@ -108,19 +109,25 @@ int transClearBuffer(SConnBuffer* buf) {
   p->left = -1;
   p->len = 0;
   p->total = 0;
+  p->invalid = 0;
   return 0;
 }
 
 int transDumpFromBuffer(SConnBuffer* connBuf, char** buf) {
+  static const int HEADSIZE = sizeof(STransMsgHead);
+
   SConnBuffer* p = connBuf;
   if (p->left != 0) {
     return -1;
   }
   int total = connBuf->total;
-  *buf = taosMemoryCalloc(1, total);
-  memcpy(*buf, p->buf, total);
-
-  transResetBuffer(connBuf);
+  if (total >= HEADSIZE && !p->invalid) {
+    *buf = taosMemoryCalloc(1, total);
+    memcpy(*buf, p->buf, total);
+    transResetBuffer(connBuf);
+  } else {
+    total = -1;
+  }
   return total;
 }
 
@@ -173,6 +180,7 @@ bool transReadComplete(SConnBuffer* connBuf) {
       memcpy((char*)&head, connBuf->buf, sizeof(head));
       int32_t msgLen = (int32_t)htonl(head.msgLen);
       p->total = msgLen;
+      p->invalid = TRANS_NOVALID_PACKET(htonl(head.magicNum));
     }
     if (p->total >= p->len) {
       p->left = p->total - p->len;
@@ -180,7 +188,8 @@ bool transReadComplete(SConnBuffer* connBuf) {
       p->left = 0;
     }
   }
-  return p->left == 0 ? true : false;
+
+  return (p->left == 0 || p->invalid) ? true : false;
 }
 
 int transSetConnOption(uv_tcp_t* stream) {
diff --git a/source/libs/transport/src/transSvr.c b/source/libs/transport/src/transSvr.c
index 3512b27bf86f71c34562f7bc928d4ecd18807684..c980b70abddd570e63d424842205e5147e2ae31f 100644
--- a/source/libs/transport/src/transSvr.c
+++ b/source/libs/transport/src/transSvr.c
@@ -183,11 +183,15 @@ static void uvHandleActivityTimeout(uv_timer_t* handle) {
   tDebug("%p timeout since no activity", conn);
 }
 
-static void uvHandleReq(SSvrConn* pConn) {
-  STransMsgHead* msg = NULL;
-  int            msgLen = 0;
+static bool uvHandleReq(SSvrConn* pConn) {
+  STrans* pTransInst = pConn->pTransInst;
 
-  msgLen = transDumpFromBuffer(&pConn->readBuf, (char**)&msg);
+  STransMsgHead* msg = NULL;
+  int            msgLen = transDumpFromBuffer(&pConn->readBuf, (char**)&msg);
+  if (msgLen <= 0) {
+    tError("%s conn %p read invalid packet", transLabel(pTransInst), pConn);
+    return false;
+  }
 
   STransMsgHead* pHead = (STransMsgHead*)msg;
   pHead->code = htonl(pHead->code);
@@ -200,9 +204,8 @@ static void uvHandleReq(SSvrConn* pConn) {
   //  uv_read_stop((uv_stream_t*)pConn->pTcp);
   //  transRefSrvHandle(pConn);
   //  uv_queue_work(((SWorkThrd*)pConn->hostThrd)->loop, wreq, uvWorkDoTask, uvWorkAfterTask);
-
   if (uvRecvReleaseReq(pConn, pHead)) {
-    return;
+    return true;
   }
 
   STransMsg transMsg;
@@ -220,7 +223,6 @@ static void uvHandleReq(SSvrConn* pConn) {
       tDebug("conn %p acquired by server app", pConn);
     }
   }
-  STrans*   pTransInst = pConn->pTransInst;
   STraceId* trace = &pHead->traceId;
   if (pConn->status == ConnNormal && pHead->noResp == 0) {
     transRefSrvHandle(pConn);
@@ -258,21 +260,31 @@ static void uvHandleReq(SSvrConn* pConn) {
   transReleaseExHandle(transGetRefMgt(), pConn->refId);
 
   (*pTransInst->cfp)(pTransInst->parent, &transMsg, NULL);
+  return true;
 }
 
 void uvOnRecvCb(uv_stream_t* cli, ssize_t nread, const uv_buf_t* buf) {
-  // opt
-  SSvrConn*    conn = cli->data;
+  SSvrConn* conn = cli->data;
+  STrans*   pTransInst = conn->pTransInst;
+
   SConnBuffer* pBuf = &conn->readBuf;
-  STrans*      pTransInst = conn->pTransInst;
   if (nread > 0) {
     pBuf->len += nread;
     tTrace("%s conn %p total read:%d, current read:%d", transLabel(pTransInst), conn, pBuf->len, (int)nread);
-    while (transReadComplete(pBuf)) {
-      tTrace("%s conn %p alread read complete packet", transLabel(pTransInst), conn);
-      uvHandleReq(conn);
+    if (pBuf->len <= TRANS_PACKET_LIMIT) {
+      while (transReadComplete(pBuf)) {
+        tTrace("%s conn %p alread read complete packet", transLabel(pTransInst), conn);
+        if (uvHandleReq(conn) == false) {
+          destroyConn(conn, true);
+          return;
+        }
+      }
+      return;
+    } else {
+      tError("%s conn %p read unexpected packet, exceed limit", transLabel(pTransInst), conn);
+      destroyConn(conn, true);
+      return;
     }
-    return;
   }
   if (nread == 0) {
     return;
@@ -364,6 +376,7 @@ static void uvPrepareSendData(SSvrMsg* smsg, uv_buf_t* wb) {
   pHead->ahandle = (uint64_t)pMsg->info.ahandle;
   pHead->traceId = pMsg->info.traceId;
   pHead->hasEpSet = pMsg->info.hasEpSet;
+  pHead->magicNum = htonl(TRANS_MAGIC_NUM);
 
   if (pConn->status == ConnNormal) {
     pHead->msgType = (0 == pMsg->msgType ? pConn->inType + 1 : pMsg->msgType);