Merge pull request #14313 from taosdata/feature/3.0_mhli

refactor(sync): refactor snapshot code

source/libs/sync/inc/syncSnapshot.h

@@ -57,7 +57,7 @@ SSyncSnapshotSender *snapshotSenderCreate(SSyncNode *pSyncNode, int32_t replicaI
 void                 snapshotSenderDestroy(SSyncSnapshotSender *pSender);
 bool                 snapshotSenderIsStart(SSyncSnapshotSender *pSender);
 void                 snapshotSenderStart(SSyncSnapshotSender *pSender, SSnapshot snapshot, void *pReader);
-void                 snapshotSenderStop(SSyncSnapshotSender *pSender);
+void                 snapshotSenderStop(SSyncSnapshotSender *pSender, bool finish);
 int32_t              snapshotSend(SSyncSnapshotSender *pSender);
 int32_t              snapshotReSend(SSyncSnapshotSender *pSender);
 
@@ -82,7 +82,7 @@ SSyncSnapshotReceiver *snapshotReceiverCreate(SSyncNode *pSyncNode, SRaftId from
 void                   snapshotReceiverDestroy(SSyncSnapshotReceiver *pReceiver);
 void snapshotReceiverStart(SSyncSnapshotReceiver *pReceiver, SyncTerm privateTerm, SyncSnapshotSend *pBeginMsg);
 bool snapshotReceiverIsStart(SSyncSnapshotReceiver *pReceiver);
-void snapshotReceiverStop(SSyncSnapshotReceiver *pReceiver, bool apply);
+void snapshotReceiverStop(SSyncSnapshotReceiver *pReceiver);
 
 cJSON *snapshotReceiver2Json(SSyncSnapshotReceiver *pReceiver);
 char  *snapshotReceiver2Str(SSyncSnapshotReceiver *pReceiver);

source/libs/sync/src/syncAppendEntriesReply.c

@@ -240,7 +240,10 @@ int32_t syncNodeOnAppendEntriesReplySnapshotCb(SSyncNode* ths, SyncAppendEntries
       SSyncSnapshotSender* pSender = syncNodeGetSnapshotSender(ths, &(pMsg->srcId));
       ASSERT(pSender != NULL);
 
-      SSnapshot snapshot;
+      SSnapshot snapshot = {.data = NULL,
+                            .lastApplyIndex = SYNC_INDEX_INVALID,
+                            .lastApplyTerm = 0,
+                            .lastConfigIndex = SYNC_INDEX_INVALID};
       void*     pReader = NULL;
       ths->pFsm->FpGetSnapshot(ths->pFsm, &snapshot, NULL, &pReader);
       if (snapshot.lastApplyIndex >= SYNC_INDEX_BEGIN && nextIndex <= snapshot.lastApplyIndex + 1 &&
@@ -249,10 +252,6 @@ int32_t syncNodeOnAppendEntriesReplySnapshotCb(SSyncNode* ths, SyncAppendEntries
         ASSERT(pReader != NULL);
         snapshotSenderStart(pSender, snapshot, pReader);
 
-        char* eventLog = snapshotSender2SimpleStr(pSender, "snapshot sender start");
-        syncNodeEventLog(ths, eventLog);
-        taosMemoryFree(eventLog);
-
       } else {
         // no snapshot
         if (pReader != NULL) {
@@ -260,23 +259,6 @@ int32_t syncNodeOnAppendEntriesReplySnapshotCb(SSyncNode* ths, SyncAppendEntries
         }
       }
 
-      /*
-            bool      hasSnapshot = syncNodeHasSnapshot(ths);
-            SSnapshot snapshot;
-            ths->pFsm->FpGetSnapshotInfo(ths->pFsm, &snapshot);
-
-            // start sending snapshot first time
-            // start here, stop by receiver
-            if (hasSnapshot && nextIndex <= snapshot.lastApplyIndex + 1 && !snapshotSenderIsStart(pSender) &&
-                pMsg->privateTerm < pSender->privateTerm) {
-              snapshotSenderStart(pSender);
-
-              char* eventLog = snapshotSender2SimpleStr(pSender, "snapshot sender start");
-              syncNodeEventLog(ths, eventLog);
-              taosMemoryFree(eventLog);
-            }
-      */
-
       SyncIndex sentryIndex = pSender->snapshot.lastApplyIndex + 1;
 
       // update nextIndex to sentryIndex
@@ -300,5 +282,5 @@ int32_t syncNodeOnAppendEntriesReplySnapshotCb(SSyncNode* ths, SyncAppendEntries
   syncIndexMgrLog2("recv sync-append-entries-reply, after pNextIndex:", ths->pNextIndex);
   syncIndexMgrLog2("recv sync-append-entries-reply, after pMatchIndex:", ths->pMatchIndex);
 
-  return ret;
+  return 0;
 }

source/libs/sync/src/syncSnapshot.c

@@ -24,6 +24,7 @@
 //----------------------------------
 static void snapshotReceiverDoStart(SSyncSnapshotReceiver *pReceiver, SyncTerm privateTerm,
                                     SyncSnapshotSend *pBeginMsg);
+static void snapshotReceiverGotData(SSyncSnapshotReceiver *pReceiver, SyncSnapshotSend *pMsg);
 
 //----------------------------------
 SSyncSnapshotSender *snapshotSenderCreate(SSyncNode *pSyncNode, int32_t replicaIndex) {
@@ -50,7 +51,7 @@ SSyncSnapshotSender *snapshotSenderCreate(SSyncNode *pSyncNode, int32_t replicaI
     pSender->pSyncNode->pFsm->FpGetSnapshotInfo(pSender->pSyncNode->pFsm, &(pSender->snapshot));
     pSender->finish = false;
   } else {
-    sError("vgId:%d cannot create snapshot sender", pSyncNode->vgId);
+    sError("vgId:%d, cannot create snapshot sender", pSyncNode->vgId);
   }
 
   return pSender;
@@ -127,7 +128,7 @@ void snapshotSenderStart(SSyncSnapshotSender *pSender, SSnapshot snapshot, void
       syncEntryDestory(pEntry);
     } else {
       if (pSender->snapshot.lastConfigIndex == pSender->pSyncNode->pRaftCfg->lastConfigIndex) {
-        sTrace("vgId:%d sync sender get cfg from local", pSender->pSyncNode->vgId);
+        sTrace("vgId:%d, sync sender get cfg from local", pSender->pSyncNode->vgId);
         pSender->lastConfig = pSender->pSyncNode->pRaftCfg->cfg;
         getLastConfig = true;
       }
@@ -176,13 +177,13 @@ void snapshotSenderStart(SSyncSnapshotSender *pSender, SSnapshot snapshot, void
 
   // event log
   do {
-    char *eventLog = snapshotSender2SimpleStr(pSender, "snapshot sender send");
+    char *eventLog = snapshotSender2SimpleStr(pSender, "snapshot sender start");
     syncNodeEventLog(pSender->pSyncNode, eventLog);
     taosMemoryFree(eventLog);
   } while (0);
 }
 
-void snapshotSenderStop(SSyncSnapshotSender *pSender) {
+void snapshotSenderStop(SSyncSnapshotSender *pSender, bool finish) {
   // close reader
   if (pSender->pReader != NULL) {
     int32_t ret = pSender->pSyncNode->pFsm->FpSnapshotStopRead(pSender->pSyncNode->pFsm, pSender->pReader);
@@ -199,6 +200,14 @@ void snapshotSenderStop(SSyncSnapshotSender *pSender) {
 
   // update flag
   pSender->start = false;
+  pSender->finish = finish;
+
+  // event log
+  do {
+    char *eventLog = snapshotSender2SimpleStr(pSender, "snapshot sender stop");
+    syncNodeEventLog(pSender->pSyncNode, eventLog);
+    taosMemoryFree(eventLog);
+  } while (0);
 }
 
 // when sender receive ack, call this function to send msg from seq
@@ -386,7 +395,7 @@ SSyncSnapshotReceiver *snapshotReceiverCreate(SSyncNode *pSyncNode, SRaftId from
     pReceiver->snapshot.lastConfigIndex = SYNC_INDEX_INVALID;
 
   } else {
-    sError("vgId:%d cannot create snapshot receiver", pSyncNode->vgId);
+    sError("vgId:%d, cannot create snapshot receiver", pSyncNode->vgId);
   }
 
   return pReceiver;
@@ -409,9 +418,9 @@ void snapshotReceiverDestroy(SSyncSnapshotReceiver *pReceiver) {
 
 bool snapshotReceiverIsStart(SSyncSnapshotReceiver *pReceiver) { return pReceiver->start; }
 
-// static do start
+// static do start by privateTerm, pBeginMsg
 // receive first snapshot data
-// privateTerm, pBeginMsg
+// write first block data
 static void snapshotReceiverDoStart(SSyncSnapshotReceiver *pReceiver, SyncTerm privateTerm,
                                     SyncSnapshotSend *pBeginMsg) {
   // update state
@@ -419,6 +428,7 @@ static void snapshotReceiverDoStart(SSyncSnapshotReceiver *pReceiver, SyncTerm p
   pReceiver->privateTerm = privateTerm;
   pReceiver->ack = SYNC_SNAPSHOT_SEQ_BEGIN;
   pReceiver->fromId = pBeginMsg->srcId;
+  pReceiver->start = true;
 
   // update snapshot
   pReceiver->snapshot.lastApplyIndex = pBeginMsg->lastIndex;
@@ -429,8 +439,16 @@ static void snapshotReceiverDoStart(SSyncSnapshotReceiver *pReceiver, SyncTerm p
   ASSERT(pReceiver->pWriter == NULL);
   int32_t ret = pReceiver->pSyncNode->pFsm->FpSnapshotStartWrite(pReceiver->pSyncNode->pFsm, &(pReceiver->pWriter));
   ASSERT(ret == 0);
+
+  // event log
+  do {
+    char *eventLog = snapshotReceiver2SimpleStr(pReceiver, "snapshot receiver start");
+    syncNodeEventLog(pReceiver->pSyncNode, eventLog);
+    taosMemoryFree(eventLog);
+  } while (0);
 }
 
+// force stop
 static void snapshotReceiverForceStop(SSyncSnapshotReceiver *pReceiver) {
   // force close, abandon incomplete data
   if (pReceiver->pWriter != NULL) {
@@ -441,33 +459,35 @@ static void snapshotReceiverForceStop(SSyncSnapshotReceiver *pReceiver) {
   }
 
   pReceiver->start = false;
+
+  // event log
+  do {
+    char *eventLog = snapshotReceiver2SimpleStr(pReceiver, "snapshot receiver force stop");
+    syncNodeEventLog(pReceiver->pSyncNode, eventLog);
+    taosMemoryFree(eventLog);
+  } while (0);
 }
 
 // if receiver receive msg from seq = SYNC_SNAPSHOT_SEQ_BEGIN, start receiver
 // if already start, force close, start again
 void snapshotReceiverStart(SSyncSnapshotReceiver *pReceiver, SyncTerm privateTerm, SyncSnapshotSend *pBeginMsg) {
   if (!snapshotReceiverIsStart(pReceiver)) {
-    // start
+    // first start
     snapshotReceiverDoStart(pReceiver, privateTerm, pBeginMsg);
-    pReceiver->start = true;
 
   } else {
     // already start
-    sInfo("snapshot recv, receiver already start");
+    sInfo("vgId:%d, snapshot recv, receiver already start", pReceiver->pSyncNode->vgId);
 
     // force close, abandon incomplete data
-    int32_t ret =
+    snapshotReceiverForceStop(pReceiver);
-        pReceiver->pSyncNode->pFsm->FpSnapshotStopWrite(pReceiver->pSyncNode->pFsm, pReceiver->pWriter, false);
-    ASSERT(ret == 0);
-    pReceiver->pWriter = NULL;
 
     // start again
     snapshotReceiverDoStart(pReceiver, privateTerm, pBeginMsg);
-    pReceiver->start = true;
   }
 }
 
-void snapshotReceiverStop(SSyncSnapshotReceiver *pReceiver, bool apply) {
+void snapshotReceiverStop(SSyncSnapshotReceiver *pReceiver) {
   if (pReceiver->pWriter != NULL) {
     int32_t ret =
         pReceiver->pSyncNode->pFsm->FpSnapshotStopWrite(pReceiver->pSyncNode->pFsm, pReceiver->pWriter, false);
@@ -477,8 +497,69 @@ void snapshotReceiverStop(SSyncSnapshotReceiver *pReceiver, bool apply) {
 
   pReceiver->start = false;
 
-  if (apply) {
+  // event log
-    //    ++(pReceiver->privateTerm);
+  do {
+    SSnapshot snapshot;
+    pReceiver->pSyncNode->pFsm->FpGetSnapshotInfo(pReceiver->pSyncNode->pFsm, &snapshot);
+    char *eventLog = snapshotReceiver2SimpleStr(pReceiver, "snapshot receiver stop");
+    syncNodeEventLog(pReceiver->pSyncNode, eventLog);
+    taosMemoryFree(eventLog);
+  } while (0);
+}
+
+static void snapshotReceiverFinish(SSyncSnapshotReceiver *pReceiver, SyncSnapshotSend *pMsg) {
+  ASSERT(pMsg->seq == SYNC_SNAPSHOT_SEQ_END);
+
+  if (pReceiver->pWriter != NULL) {
+    int32_t code = 0;
+    if (pMsg->dataLen > 0) {
+      code = pReceiver->pSyncNode->pFsm->FpSnapshotDoWrite(pReceiver->pSyncNode->pFsm, pReceiver->pWriter, pMsg->data,
+                                                           pMsg->dataLen);
+      ASSERT(code == 0);
+    }
+
+    code = pReceiver->pSyncNode->pFsm->FpSnapshotStopWrite(pReceiver->pSyncNode->pFsm, pReceiver->pWriter, true);
+    ASSERT(code == 0);
+    pReceiver->pWriter = NULL;
+  }
+
+  pReceiver->ack = SYNC_SNAPSHOT_SEQ_END;
+
+  // update commit index
+  if (pReceiver->snapshot.lastApplyIndex > pReceiver->pSyncNode->commitIndex) {
+    pReceiver->pSyncNode->commitIndex = pReceiver->snapshot.lastApplyIndex;
+  }
+
+  // reset wal
+  pReceiver->pSyncNode->pLogStore->syncLogRestoreFromSnapshot(pReceiver->pSyncNode->pLogStore, pMsg->lastIndex);
+
+  // event log
+  do {
+    SSnapshot snapshot;
+    pReceiver->pSyncNode->pFsm->FpGetSnapshotInfo(pReceiver->pSyncNode->pFsm, &snapshot);
+    char *eventLog = snapshotReceiver2SimpleStr(pReceiver, "snapshot receiver got last data, finish, apply snapshot");
+    syncNodeEventLog(pReceiver->pSyncNode, eventLog);
+    taosMemoryFree(eventLog);
+  } while (0);
+}
+
+static void snapshotReceiverGotData(SSyncSnapshotReceiver *pReceiver, SyncSnapshotSend *pMsg) {
+  ASSERT(pMsg->seq == pReceiver->ack + 1);
+
+  if (pReceiver->pWriter != NULL) {
+    if (pMsg->dataLen > 0) {
+      int32_t code = pReceiver->pSyncNode->pFsm->FpSnapshotDoWrite(pReceiver->pSyncNode->pFsm, pReceiver->pWriter,
+                                                                   pMsg->data, pMsg->dataLen);
+      ASSERT(code == 0);
+    }
+    pReceiver->ack = pMsg->seq;
+
+    // event log
+    do {
+      char *eventLog = snapshotReceiver2SimpleStr(pReceiver, "snapshot receiver receiving");
+      syncNodeEventLog(pReceiver->pSyncNode, eventLog);
+      taosMemoryFree(eventLog);
+    } while (0);
   }
 }
 
@@ -560,33 +641,20 @@ int32_t syncNodeOnSnapshotSendCb(SSyncNode *pSyncNode, SyncSnapshotSend *pMsg) {
   // get receiver
   SSyncSnapshotReceiver *pReceiver = pSyncNode->pNewNodeReceiver;
   bool                   needRsp = false;
-  int32_t                writeCode = 0;
 
   // state, term, seq/ack
   if (pSyncNode->state == TAOS_SYNC_STATE_FOLLOWER) {
     if (pMsg->term == pSyncNode->pRaftStore->currentTerm) {
       if (pMsg->seq == SYNC_SNAPSHOT_SEQ_BEGIN) {
-        // begin
+        // begin, no data
         snapshotReceiverStart(pReceiver, pMsg->privateTerm, pMsg);
-        pReceiver->ack = pMsg->seq;
         needRsp = true;
 
-        char *eventLog = snapshotReceiver2SimpleStr(pReceiver, "snapshot receiver begin");
-        syncNodeEventLog(pSyncNode, eventLog);
-        taosMemoryFree(eventLog);
-
       } else if (pMsg->seq == SYNC_SNAPSHOT_SEQ_END) {
         // end, finish FSM
-        writeCode = pSyncNode->pFsm->FpSnapshotDoWrite(pSyncNode->pFsm, pReceiver->pWriter, pMsg->data, pMsg->dataLen);
+        snapshotReceiverFinish(pReceiver, pMsg);
-        ASSERT(writeCode == 0);
+        snapshotReceiverStop(pReceiver);
-
+        needRsp = true;
-        pSyncNode->pFsm->FpSnapshotStopWrite(pSyncNode->pFsm, pReceiver->pWriter, true);
-        if (pReceiver->snapshot.lastApplyIndex > pReceiver->pSyncNode->commitIndex) {
-          pReceiver->pSyncNode->commitIndex = pReceiver->snapshot.lastApplyIndex;
-        }
-
-        // pSyncNode->pLogStore->syncLogSetBeginIndex(pSyncNode->pLogStore, pMsg->lastIndex + 1);
-        pSyncNode->pLogStore->syncLogRestoreFromSnapshot(pSyncNode->pLogStore, pMsg->lastIndex);
 
         // maybe update lastconfig
         if (pMsg->lastConfigIndex >= SYNC_INDEX_BEGIN) {
@@ -601,89 +669,74 @@ int32_t syncNodeOnSnapshotSendCb(SSyncNode *pSyncNode, SyncSnapshotSend *pMsg) {
           syncNodeDoConfigChange(pSyncNode, &newSyncCfg, pMsg->lastConfigIndex);
         }
 
-        SSnapshot snapshot;
-        pSyncNode->pFsm->FpGetSnapshotInfo(pSyncNode->pFsm, &snapshot);
-
-        do {
-          char *eventLog = snapshotReceiver2SimpleStr(pReceiver, "snapshot receiver finish, apply snapshot");
-          syncNodeEventLog(pSyncNode, eventLog);
-          taosMemoryFree(eventLog);
-        } while (0);
-
-        pReceiver->pWriter = NULL;
-        snapshotReceiverStop(pReceiver, true);
-        pReceiver->ack = pMsg->seq;
-        needRsp = true;
-
-        do {
-          char *eventLog = snapshotReceiver2SimpleStr(pReceiver, "snapshot receiver stop");
-          syncNodeEventLog(pSyncNode, eventLog);
-          taosMemoryFree(eventLog);
-        } while (0);
-
       } else if (pMsg->seq == SYNC_SNAPSHOT_SEQ_FORCE_CLOSE) {
-        pSyncNode->pFsm->FpSnapshotStopWrite(pSyncNode->pFsm, pReceiver->pWriter, false);
+        // force close
-        snapshotReceiverStop(pReceiver, false);
+        snapshotReceiverForceStop(pReceiver);
         needRsp = false;
 
-        do {
-          char *eventLog = snapshotReceiver2SimpleStr(pReceiver, "snapshot receiver force close");
-          syncNodeEventLog(pSyncNode, eventLog);
-          taosMemoryFree(eventLog);
-        } while (0);
-
       } else if (pMsg->seq > SYNC_SNAPSHOT_SEQ_BEGIN && pMsg->seq < SYNC_SNAPSHOT_SEQ_END) {
         // transfering
         if (pMsg->seq == pReceiver->ack + 1) {
-          writeCode =
+          snapshotReceiverGotData(pReceiver, pMsg);
-              pSyncNode->pFsm->FpSnapshotDoWrite(pSyncNode->pFsm, pReceiver->pWriter, pMsg->data, pMsg->dataLen);
-          ASSERT(writeCode == 0);
-          pReceiver->ack = pMsg->seq;
         }
         needRsp = true;
 
-        do {
-          char *eventLog = snapshotReceiver2SimpleStr(pReceiver, "snapshot receiver receiving");
-          syncNodeEventLog(pSyncNode, eventLog);
-          taosMemoryFree(eventLog);
-        } while (0);
-
       } else {
         ASSERT(0);
       }
 
+      // send ack
       if (needRsp) {
+        // build msg
         SyncSnapshotRsp *pRspMsg = syncSnapshotRspBuild(pSyncNode->vgId);
         pRspMsg->srcId = pSyncNode->myRaftId;
         pRspMsg->destId = pMsg->srcId;
         pRspMsg->term = pSyncNode->pRaftStore->currentTerm;
         pRspMsg->lastIndex = pMsg->lastIndex;
         pRspMsg->lastTerm = pMsg->lastTerm;
-        pRspMsg->ack = pReceiver->ack;
+        pRspMsg->ack = pReceiver->ack;  // receiver maybe already closed
-        pRspMsg->code = writeCode;
+        pRspMsg->code = 0;
-        pRspMsg->privateTerm = pReceiver->privateTerm;
+        pRspMsg->privateTerm = pReceiver->privateTerm;  // receiver maybe already closed
 
+        // send msg
         SRpcMsg rpcMsg;
         syncSnapshotRsp2RpcMsg(pRspMsg, &rpcMsg);
         syncNodeSendMsgById(&(pRspMsg->destId), pSyncNode, &rpcMsg);
-
         syncSnapshotRspDestroy(pRspMsg);
       }
+    } else {
+      // error log
+      do {
+        char *eventLog = snapshotReceiver2SimpleStr(pReceiver, "snapshot receiver term not equal");
+        syncNodeErrorLog(pSyncNode, eventLog);
+        taosMemoryFree(eventLog);
+      } while (0);
     }
   } else {
-    syncNodeLog2("syncNodeOnSnapshotSendCb not follower", pSyncNode);
+    // error log
+    do {
+      char *eventLog = snapshotReceiver2SimpleStr(pReceiver, "snapshot receiver not follower");
+      syncNodeErrorLog(pSyncNode, eventLog);
+      taosMemoryFree(eventLog);
+    } while (0);
   }
 
   return 0;
 }
 
+static void snapshotSenderUpdateProgress(SSyncSnapshotSender *pSender, SyncSnapshotRsp *pMsg) {
+  ASSERT(pMsg->ack == pSender->seq);
+  pSender->ack = pMsg->ack;
+  ++(pSender->seq);
+}
+
 // sender receives ack, set seq = ack + 1, send msg from seq
 // if ack == SYNC_SNAPSHOT_SEQ_END, stop sender
 int32_t syncNodeOnSnapshotRspCb(SSyncNode *pSyncNode, SyncSnapshotRsp *pMsg) {
   // if already drop replica, do not process
   if (!syncNodeInRaftGroup(pSyncNode, &(pMsg->srcId)) && pSyncNode->state == TAOS_SYNC_STATE_LEADER) {
-    sInfo("recv SyncSnapshotRsp maybe replica already dropped");
+    sError("vgId:%d, recv sync-snapshot-rsp, maybe replica already dropped", pSyncNode->vgId);
-    return 0;
+    return -1;
   }
 
   // get sender
@@ -695,27 +748,49 @@ int32_t syncNodeOnSnapshotRspCb(SSyncNode *pSyncNode, SyncSnapshotRsp *pMsg) {
     if (pMsg->term == pSyncNode->pRaftStore->currentTerm) {
       // receiver ack is finish, close sender
       if (pMsg->ack == SYNC_SNAPSHOT_SEQ_END) {
-        pSender->finish = true;
+        snapshotSenderStop(pSender, true);
-        snapshotSenderStop(pSender);
         return 0;
       }
 
       // send next msg
       if (pMsg->ack == pSender->seq) {
         // update sender ack
-        pSender->ack = pMsg->ack;
+        snapshotSenderUpdateProgress(pSender, pMsg);
-        (pSender->seq)++;
         snapshotSend(pSender);
 
       } else if (pMsg->ack == pSender->seq - 1) {
         snapshotReSend(pSender);
 
       } else {
-        ASSERT(0);
+        do {
-      }
+          char logBuf[64];
+          snprintf(logBuf, sizeof(logBuf), "error ack, recv ack:%d, my seq:%d", pMsg->ack, pSender->seq);
+          char *eventLog = snapshotSender2SimpleStr(pSender, logBuf);
+          syncNodeErrorLog(pSyncNode, eventLog);
+          taosMemoryFree(eventLog);
+        } while (0);
+
+        return -1;
       }
     } else {
-    syncNodeLog2("syncNodeOnSnapshotRspCb not leader", pSyncNode);
+      // error log
+      do {
+        char *eventLog = snapshotSender2SimpleStr(pSender, "snapshot sender term not equal");
+        syncNodeErrorLog(pSyncNode, eventLog);
+        taosMemoryFree(eventLog);
+      } while (0);
+
+      return -1;
+    }
+  } else {
+    // error log
+    do {
+      char *eventLog = snapshotSender2SimpleStr(pSender, "snapshot sender not leader");
+      syncNodeErrorLog(pSyncNode, eventLog);
+      taosMemoryFree(eventLog);
+    } while (0);
+
+    return -1;
   }
 
   return 0;