refactor(sync): append entries

include/libs/sync/sync.h

@@ -37,6 +37,8 @@ extern bool gRaftDetailLog;
 #define SYNC_MAX_RECV_TIME_RANGE_MS 1200
 #define SYNC_ADD_QUORUM_COUNT 3
 
+#define SYNC_APPEND_ENTRIES_TIMEOUT_MS 10000
+
 #define SYNC_MAX_BATCH_SIZE 1
 #define SYNC_INDEX_BEGIN 0
 #define SYNC_INDEX_INVALID -1

include/libs/sync/syncTools.h

@@ -423,6 +423,7 @@ typedef struct SyncAppendEntriesReply {
   SyncTerm  privateTerm;
   bool      success;
   SyncIndex matchIndex;
+  SyncIndex lastSendIndex;
   int64_t   startTime;
 } SyncAppendEntriesReply;
 
@@ -698,6 +699,7 @@ int32_t syncNodeOnSnapshotRspCb(SSyncNode* ths, SyncSnapshotRsp* pMsg);
 int32_t syncNodeOnHeartbeat(SSyncNode* ths, SyncHeartbeat* pMsg);
 int32_t syncNodeOnHeartbeatReply(SSyncNode* ths, SyncHeartbeatReply* pMsg);
 
+int32_t syncNodeOnClientRequest(SSyncNode* ths, SyncClientRequest* pMsg, SyncIndex* pRetIndex);
 int32_t syncNodeOnRequestVote(SSyncNode* ths, SyncRequestVote* pMsg);
 int32_t syncNodeOnRequestVoteReply(SSyncNode* ths, SyncRequestVoteReply* pMsg);
 int32_t syncNodeOnAppendEntries(SSyncNode* ths, SyncAppendEntries* pMsg);

source/dnode/vnode/src/vnd/vnodeSync.c

@@ -407,7 +407,7 @@ int32_t vnodeProcessSyncMsg(SVnode *pVnode, SRpcMsg *pMsg, SRpcMsg **pRsp) {
   } else if (pMsg->msgType == TDMT_SYNC_CLIENT_REQUEST) {
     SyncClientRequest *pSyncMsg = syncClientRequestFromRpcMsg2(pMsg);
     ASSERT(pSyncMsg != NULL);
-    code = syncNodeOnClientRequestCb(pSyncNode, pSyncMsg, NULL);
+    code = syncNodeOnClientRequest(pSyncNode, pSyncMsg, NULL);
     syncClientRequestDestroy(pSyncMsg);
 
   } else if (pMsg->msgType == TDMT_SYNC_CLIENT_REQUEST_BATCH) {

source/libs/sync/inc/syncInt.h

@@ -83,6 +83,11 @@ int32_t syncHbTimerInit(SSyncNode* pSyncNode, SSyncTimer* pSyncTimer, SRaftId de
 int32_t syncHbTimerStart(SSyncNode* pSyncNode, SSyncTimer* pSyncTimer);
 int32_t syncHbTimerStop(SSyncNode* pSyncNode, SSyncTimer* pSyncTimer);
 
+typedef struct SPeerState {
+  SyncIndex lastSendIndex;
+  int64_t   lastSendTime;
+} SPeerState;
+
 typedef struct SSyncNode {
   // init by SSyncInfo
   SyncGroupId vgId;
@@ -186,6 +191,8 @@ typedef struct SSyncNode {
   SSyncSnapshotSender*   senders[TSDB_MAX_REPLICA];
   SSyncSnapshotReceiver* pNewNodeReceiver;
 
+  SPeerState peerStates[TSDB_MAX_REPLICA];
+
   // is config changing
   bool changing;
 
@@ -283,6 +290,8 @@ int32_t syncNodeUpdateNewConfigIndex(SSyncNode* ths, SSyncCfg* pNewCfg);
 bool                 syncNodeInRaftGroup(SSyncNode* ths, SRaftId* pRaftId);
 SSyncSnapshotSender* syncNodeGetSnapshotSender(SSyncNode* ths, SRaftId* pDestId);
 SSyncTimer*          syncNodeGetHbTimer(SSyncNode* ths, SRaftId* pDestId);
+SPeerState*          syncNodeGetPeerState(SSyncNode* ths, const SRaftId* pDestId);
+bool syncNodeNeedSendAppendEntries(SSyncNode* ths, const SRaftId* pDestId, const SyncAppendEntries* pMsg);
 
 int32_t syncGetSnapshotMeta(int64_t rid, struct SSnapshotMeta* sMeta);
 int32_t syncGetSnapshotMetaByIndex(int64_t rid, SyncIndex snapshotIndex, struct SSnapshotMeta* sMeta);
@@ -300,6 +309,8 @@ int32_t syncDoLeaderTransfer(SSyncNode* ths, SRpcMsg* pRpcMsg, SSyncRaftEntry* p
 int32_t syncNodeDynamicQuorum(const SSyncNode* pSyncNode);
 
 bool    syncNodeIsMnode(SSyncNode* pSyncNode);
+int32_t syncNodePeerStateInit(SSyncNode* pSyncNode);
+void    syncNodeStepDown(SSyncNode* pSyncNode, SyncTerm newTerm);
 
 // trace log
 void syncLogSendRequestVote(SSyncNode* pSyncNode, const SyncRequestVote* pMsg, const char* s);

source/libs/sync/inc/syncReplication.h

@@ -61,9 +61,16 @@ int32_t syncNodeReplicate(SSyncNode* pSyncNode, bool isTimer);
 int32_t syncNodeAppendEntries(SSyncNode* pSyncNode, const SRaftId* destRaftId, const SyncAppendEntries* pMsg);
 int32_t syncNodeAppendEntriesBatch(SSyncNode* pSyncNode, const SRaftId* destRaftId, const SyncAppendEntriesBatch* pMsg);
 
+//---------------------------------------------
+
 int32_t syncNodeHeartbeat(SSyncNode* pSyncNode, const SRaftId* destRaftId, const SyncHeartbeat* pMsg);
 int32_t syncNodeHeartbeatPeers(SSyncNode* pSyncNode);
 
+int32_t syncNodeDoReplicate(SSyncNode* pSyncNode);
+int32_t syncNodeDoAppendEntries(SSyncNode* pSyncNode, SRaftId* pDestId);
+int32_t syncNodeSendAppendEntries(SSyncNode* pSyncNode, const SRaftId* destRaftId, const SyncAppendEntries* pMsg);
+int32_t syncNodeMaybeSendAppendEntries(SSyncNode* pSyncNode, const SRaftId* destRaftId, const SyncAppendEntries* pMsg);
+
 #ifdef __cplusplus
 }
 #endif

source/libs/sync/src/syncAppendEntries.c

@@ -1042,4 +1042,123 @@ int32_t syncNodeOnAppendEntriesSnapshotCb(SSyncNode* ths, SyncAppendEntries* pMs
   return ret;
 }
 
-int32_t syncNodeOnAppendEntries(SSyncNode* ths, SyncAppendEntries* pMsg) { return 0; }
+int32_t syncNodeOnAppendEntries(SSyncNode* ths, SyncAppendEntries* pMsg) {
+  // prepare response msg
+  SyncAppendEntriesReply* pReply = syncAppendEntriesReplyBuild(ths->vgId);
+  pReply->srcId = ths->myRaftId;
+  pReply->destId = pMsg->srcId;
+  pReply->term = ths->pRaftStore->currentTerm;
+  pReply->success = false;
+  pReply->matchIndex = ths->pLogStore->syncLogLastIndex(ths->pLogStore);
+  pReply->lastSendIndex = pMsg->prevLogIndex + 1;
+  pReply->privateTerm = ths->pNewNodeReceiver->privateTerm;
+  pReply->startTime = ths->startTime;
+
+  if (pMsg->term < ths->pRaftStore->currentTerm) {
+    goto _SEND_RESPONSE;
+  }
+
+  if (pMsg->term > ths->pRaftStore->currentTerm) {
+    pReply->term = pMsg->term;
+    goto _SEND_RESPONSE;
+  }
+
+  syncNodeStepDown(ths, pMsg->term);
+  syncNodeResetElectTimer(ths);
+
+  SyncIndex startIndex = ths->pLogStore->syncLogBeginIndex(ths->pLogStore);
+  SyncIndex lastIndex = ths->pLogStore->syncLogLastIndex(ths->pLogStore);
+
+  if (pMsg->prevLogIndex > lastIndex) {
+    goto _SEND_RESPONSE;
+  }
+
+  if (pMsg->prevLogIndex >= startIndex) {
+    SyncTerm myPreLogTerm = syncNodeGetPreTerm(ths, pMsg->prevLogIndex + 1);
+    ASSERT(myPreLogTerm != SYNC_TERM_INVALID);
+
+    if (myPreLogTerm != pMsg->prevLogTerm) {
+      goto _SEND_RESPONSE;
+    }
+  }
+
+  // accept
+  pReply->success = true;
+  bool hasAppendEntries = pMsg->dataLen > 0;
+  if (hasAppendEntries) {
+    SSyncRaftEntry* pAppendEntry = syncEntryDeserialize(pMsg->data, pMsg->dataLen);
+    ASSERT(pAppendEntry != NULL);
+
+    SyncIndex       appendIndex = pMsg->prevLogIndex + 1;
+    SSyncRaftEntry* pLocalEntry = NULL;
+    int32_t         code = ths->pLogStore->syncLogGetEntry(ths->pLogStore, appendIndex, &pLocalEntry);
+    ASSERT(code == 0);
+
+    if (pLocalEntry->term == pAppendEntry->term) {
+      // do nothing
+    } else {
+      code = ths->pLogStore->syncLogTruncate(ths->pLogStore, appendIndex);
+      ASSERT(code == 0);
+
+      code = ths->pLogStore->syncLogAppendEntry(ths->pLogStore, pAppendEntry);
+      ASSERT(code == 0);
+    }
+
+    syncEntryDestory(pLocalEntry);
+    syncEntryDestory(pAppendEntry);
+  }
+
+  // update match index
+  pReply->matchIndex = ths->pLogStore->syncLogLastIndex(ths->pLogStore);
+
+  // maybe update commit index, leader notice me
+  if (pMsg->commitIndex > ths->commitIndex) {
+    // has commit entry in local
+    if (pMsg->commitIndex <= ths->pLogStore->syncLogLastIndex(ths->pLogStore)) {
+      // advance commit index to sanpshot first
+      SSnapshot snapshot;
+      ths->pFsm->FpGetSnapshotInfo(ths->pFsm, &snapshot);
+      if (snapshot.lastApplyIndex >= 0 && snapshot.lastApplyIndex > ths->commitIndex) {
+        SyncIndex commitBegin = ths->commitIndex;
+        SyncIndex commitEnd = snapshot.lastApplyIndex;
+        ths->commitIndex = snapshot.lastApplyIndex;
+
+        char eventLog[128];
+        snprintf(eventLog, sizeof(eventLog), "commit by snapshot from index:%" PRId64 " to index:%" PRId64, commitBegin,
+                 commitEnd);
+        syncNodeEventLog(ths, eventLog);
+      }
+
+      SyncIndex beginIndex = ths->commitIndex + 1;
+      SyncIndex endIndex = pMsg->commitIndex;
+
+      // update commit index
+      ths->commitIndex = pMsg->commitIndex;
+
+      // call back Wal
+      int32_t code = ths->pLogStore->updateCommitIndex(ths->pLogStore, ths->commitIndex);
+      ASSERT(code == 0);
+
+      code = syncNodeCommit(ths, beginIndex, endIndex, ths->state);
+      ASSERT(code == 0);
+    }
+  }
+
+  goto _SEND_RESPONSE;
+
+_IGNORE:
+  syncAppendEntriesReplyDestroy(pReply);
+  return 0;
+
+_SEND_RESPONSE:
+  // msg event log
+  syncLogSendAppendEntriesReply(ths, pReply, "");
+
+  // send response
+  SRpcMsg rpcMsg;
+  syncAppendEntriesReply2RpcMsg(pReply, &rpcMsg);
+  syncNodeSendMsgById(&pReply->destId, ths, &rpcMsg);
+  syncAppendEntriesReplyDestroy(pReply);
+
+  return 0;
+}

source/libs/sync/src/syncAppendEntriesReply.c

@@ -20,6 +20,7 @@
 #include "syncRaftCfg.h"
 #include "syncRaftLog.h"
 #include "syncRaftStore.h"
+#include "syncReplication.h"
 #include "syncSnapshot.h"
 #include "syncUtil.h"
 #include "syncVoteMgr.h"
@@ -415,4 +416,54 @@ int32_t syncNodeOnAppendEntriesReplySnapshotCb(SSyncNode* ths, SyncAppendEntries
   return 0;
 }
 
-int32_t syncNodeOnAppendEntriesReply(SSyncNode* ths, SyncAppendEntriesReply* pMsg) { return 0; }
+int32_t syncNodeOnAppendEntriesReply(SSyncNode* ths, SyncAppendEntriesReply* pMsg) {
+  int32_t ret = 0;
+
+  // if already drop replica, do not process
+  if (!syncNodeInRaftGroup(ths, &(pMsg->srcId)) && !ths->pRaftCfg->isStandBy) {
+    syncLogRecvAppendEntriesReply(ths, pMsg, "maybe replica already dropped");
+    return -1;
+  }
+
+  // drop stale response
+  if (pMsg->term < ths->pRaftStore->currentTerm) {
+    syncLogRecvAppendEntriesReply(ths, pMsg, "drop stale response");
+    return 0;
+  }
+
+  if (ths->state == TAOS_SYNC_STATE_LEADER) {
+    if (pMsg->term > ths->pRaftStore->currentTerm) {
+      syncLogRecvAppendEntriesReply(ths, pMsg, "error term");
+      syncNodeStepDown(ths, pMsg->term);
+      return -1;
+    }
+
+    ASSERT(pMsg->term == ths->pRaftStore->currentTerm);
+
+    if (pMsg->success) {
+      SyncIndex oldMatchIndex = syncIndexMgrGetIndex(ths->pMatchIndex, &(pMsg->srcId));
+      if (pMsg->matchIndex > oldMatchIndex) {
+        syncIndexMgrSetIndex(ths->pMatchIndex, &(pMsg->srcId), pMsg->matchIndex);
+        syncMaybeAdvanceCommitIndex(ths);
+      }
+      syncIndexMgrSetIndex(ths->pNextIndex, &(pMsg->srcId), pMsg->matchIndex + 1);
+
+    } else {
+      SyncIndex nextIndex = syncIndexMgrGetIndex(ths->pNextIndex, &(pMsg->srcId));
+      if (nextIndex > SYNC_INDEX_BEGIN) {
+        --nextIndex;
+      }
+      syncIndexMgrSetIndex(ths->pNextIndex, &(pMsg->srcId), nextIndex);
+    }
+
+    // send next append entries
+    SPeerState* pState = syncNodeGetPeerState(ths, &(pMsg->srcId));
+    ASSERT(pState != NULL);
+
+    if (pMsg->lastSendIndex == pState->lastSendIndex) {
+      syncNodeDoAppendEntries(ths, &(pMsg->srcId));
+    }
+  }
+
+  return 0;
+}

source/libs/sync/src/syncMain.c

@@ -1219,6 +1219,9 @@ SSyncNode* syncNodeOpen(const SSyncInfo* pOldSyncInfo) {
   // is config changing
   pSyncNode->changing = false;
 
+  // peer state
+  syncNodePeerStateInit(pSyncNode);
+
   // start in syncNodeStart
   // start raft
   // syncNodeBecomeFollower(pSyncNode);
@@ -2331,6 +2334,32 @@ void syncNodeCandidate2Leader(SSyncNode* pSyncNode) {
 
 bool syncNodeIsMnode(SSyncNode* pSyncNode) { return (pSyncNode->vgId == 1); }
 
+int32_t syncNodePeerStateInit(SSyncNode* pSyncNode) {
+  for (int i = 0; i < TSDB_MAX_REPLICA; ++i) {
+    pSyncNode->peerStates[i].lastSendIndex = SYNC_INDEX_INVALID;
+    pSyncNode->peerStates[i].lastSendTime = 0;
+  }
+
+  return 0;
+}
+
+void syncNodeStepDown(SSyncNode* pSyncNode, SyncTerm newTerm) {
+  ASSERT(pSyncNode->pRaftStore->currentTerm <= newTerm);
+
+  if (pSyncNode->pRaftStore->currentTerm < newTerm) {
+    raftStoreSetTerm(pSyncNode->pRaftStore, newTerm);
+    char tmpBuf[64];
+    snprintf(tmpBuf, sizeof(tmpBuf), "step down, update term to %" PRIu64, newTerm);
+    syncNodeBecomeFollower(pSyncNode, tmpBuf);
+    raftStoreClearVote(pSyncNode->pRaftStore);
+
+  } else {
+    if (pSyncNode->state != TAOS_SYNC_STATE_FOLLOWER) {
+      syncNodeBecomeFollower(pSyncNode, "step down");
+    }
+  }
+}
+
 void syncNodeFollower2Candidate(SSyncNode* pSyncNode) {
   ASSERT(pSyncNode->state == TAOS_SYNC_STATE_FOLLOWER);
   pSyncNode->state = TAOS_SYNC_STATE_CANDIDATE;
@@ -2924,6 +2953,55 @@ int32_t syncNodeOnClientRequestCb(SSyncNode* ths, SyncClientRequest* pMsg, SyncI
   return ret;
 }
 
+int32_t syncNodeOnClientRequest(SSyncNode* ths, SyncClientRequest* pMsg, SyncIndex* pRetIndex) {
+  int32_t ret = 0;
+  int32_t code = 0;
+
+  SyncIndex       index = ths->pLogStore->syncLogWriteIndex(ths->pLogStore);
+  SyncTerm        term = ths->pRaftStore->currentTerm;
+  SSyncRaftEntry* pEntry = syncEntryBuild2((SyncClientRequest*)pMsg, term, index);
+  ASSERT(pEntry != NULL);
+
+  LRUHandle* h = NULL;
+  syncCacheEntry(ths->pLogStore, pEntry, &h);
+
+  if (ths->state == TAOS_SYNC_STATE_LEADER) {
+    // append entry
+    code = ths->pLogStore->syncLogAppendEntry(ths->pLogStore, pEntry);
+    if (code != 0) {
+      // del resp mgr, call FpCommitCb
+      ASSERT(0);
+      return -1;
+    }
+
+    // if mulit replica, start replicate right now
+    if (ths->replicaNum > 1) {
+      syncNodeDoReplicate(ths);
+    }
+
+    // if only myself, maybe commit right now
+    if (ths->replicaNum == 1) {
+      syncMaybeAdvanceCommitIndex(ths);
+    }
+  }
+
+  if (pRetIndex != NULL) {
+    if (ret == 0 && pEntry != NULL) {
+      *pRetIndex = pEntry->index;
+    } else {
+      *pRetIndex = SYNC_INDEX_INVALID;
+    }
+  }
+
+  if (h) {
+    taosLRUCacheRelease(ths->pLogStore->pCache, h, false);
+  } else {
+    syncEntryDestory(pEntry);
+  }
+
+  return ret;
+}
+
 int32_t syncNodeOnClientRequestBatchCb(SSyncNode* ths, SyncClientRequestBatch* pMsg) {
   int32_t code = 0;
 
@@ -3331,6 +3409,30 @@ SSyncTimer* syncNodeGetHbTimer(SSyncNode* ths, SRaftId* pDestId) {
   return pTimer;
 }
 
+SPeerState* syncNodeGetPeerState(SSyncNode* ths, const SRaftId* pDestId) {
+  SPeerState* pState = NULL;
+  for (int i = 0; i < ths->replicaNum; ++i) {
+    if (syncUtilSameId(pDestId, &((ths->replicasId)[i]))) {
+      pState = &((ths->peerStates)[i]);
+    }
+  }
+  return pState;
+}
+
+bool syncNodeNeedSendAppendEntries(SSyncNode* ths, const SRaftId* pDestId, const SyncAppendEntries* pMsg) {
+  SPeerState* pState = syncNodeGetPeerState(ths, pDestId);
+  ASSERT(pState != NULL);
+
+  SyncIndex sendIndex = pMsg->prevLogIndex + 1;
+  int64_t   tsNow = taosGetTimestampMs();
+
+  if (pState->lastSendIndex == sendIndex && tsNow - pState->lastSendTime < SYNC_APPEND_ENTRIES_TIMEOUT_MS) {
+    return false;
+  }
+
+  return true;
+}
+
 bool syncNodeCanChange(SSyncNode* pSyncNode) {
   if (pSyncNode->changing) {
     sError("sync cannot change");

source/libs/sync/src/syncReplication.c

@@ -478,6 +478,118 @@ int32_t syncNodeReplicate(SSyncNode* pSyncNode, bool isTimer) {
   return ret;
 }
 
+int32_t syncNodeDoAppendEntries(SSyncNode* pSyncNode, SRaftId* pDestId) {
+  // next index
+  SyncIndex nextIndex = syncIndexMgrGetIndex(pSyncNode->pNextIndex, pDestId);
+
+  // maybe start snapshot
+  SyncIndex logStartIndex = pSyncNode->pLogStore->syncLogBeginIndex(pSyncNode->pLogStore);
+  SyncIndex logEndIndex = pSyncNode->pLogStore->syncLogEndIndex(pSyncNode->pLogStore);
+  if (nextIndex < logStartIndex || nextIndex > logEndIndex) {
+    // start snapshot
+    return 0;
+  }
+
+  // pre index, pre term
+  SyncIndex preLogIndex = syncNodeGetPreIndex(pSyncNode, nextIndex);
+  SyncTerm  preLogTerm = syncNodeGetPreTerm(pSyncNode, nextIndex);
+
+  // prepare entry
+  SyncAppendEntries* pMsg = NULL;
+
+  SSyncRaftEntry* pEntry;
+  int32_t         code = pSyncNode->pLogStore->syncLogGetEntry(pSyncNode->pLogStore, nextIndex, &pEntry);
+
+  if (code == 0) {
+    ASSERT(pEntry != NULL);
+
+    pMsg = syncAppendEntriesBuild(pEntry->bytes, pSyncNode->vgId);
+    ASSERT(pMsg != NULL);
+
+    // add pEntry into msg
+    uint32_t len;
+    char*    serialized = syncEntrySerialize(pEntry, &len);
+    ASSERT(len == pEntry->bytes);
+    memcpy(pMsg->data, serialized, len);
+
+    taosMemoryFree(serialized);
+    syncEntryDestory(pEntry);
+
+  } else {
+    if (terrno == TSDB_CODE_WAL_LOG_NOT_EXIST) {
+      // no entry in log
+      pMsg = syncAppendEntriesBuild(0, pSyncNode->vgId);
+      ASSERT(pMsg != NULL);
+
+    } else {
+      syncNodeLog3("", pSyncNode);
+      ASSERT(0);
+    }
+  }
+
+  // prepare msg
+  ASSERT(pMsg != NULL);
+  pMsg->srcId = pSyncNode->myRaftId;
+  pMsg->destId = *pDestId;
+  pMsg->term = pSyncNode->pRaftStore->currentTerm;
+  pMsg->prevLogIndex = preLogIndex;
+  pMsg->prevLogTerm = preLogTerm;
+  pMsg->commitIndex = pSyncNode->commitIndex;
+  pMsg->privateTerm = 0;
+  // pMsg->privateTerm = syncIndexMgrGetTerm(pSyncNode->pNextIndex, pDestId);
+
+  // send msg
+  syncNodeMaybeSendAppendEntries(pSyncNode, pDestId, pMsg);
+  syncAppendEntriesDestroy(pMsg);
+
+  return 0;
+}
+
+int32_t syncNodeDoReplicate(SSyncNode* pSyncNode) {
+  if (pSyncNode->state != TAOS_SYNC_STATE_LEADER) {
+    return -1;
+  }
+
+  int32_t ret = 0;
+  for (int i = 0; i < pSyncNode->peersNum; ++i) {
+    SRaftId* pDestId = &(pSyncNode->peersId[i]);
+    ret = syncNodeDoAppendEntries(pSyncNode, pDestId);
+    if (ret != 0) {
+      char    host[64];
+      int16_t port;
+      syncUtilU642Addr(pDestId->addr, host, sizeof(host), &port);
+      sError("vgId:%d, do append entries error for %s:%d", pSyncNode->vgId, host, port);
+    }
+  }
+
+  return 0;
+}
+
+int32_t syncNodeSendAppendEntries(SSyncNode* pSyncNode, const SRaftId* destRaftId, const SyncAppendEntries* pMsg) {
+  int32_t ret = 0;
+  syncLogSendAppendEntries(pSyncNode, pMsg, "");
+
+  SRpcMsg rpcMsg;
+  syncAppendEntries2RpcMsg(pMsg, &rpcMsg);
+  syncNodeSendMsgById(destRaftId, pSyncNode, &rpcMsg);
+
+  SPeerState* pState = syncNodeGetPeerState(pSyncNode, destRaftId);
+  ASSERT(pState != NULL);
+
+  pState->lastSendIndex = pMsg->prevLogIndex + 1;
+  pState->lastSendTime = taosGetTimestampMs();
+
+  return ret;
+}
+
+int32_t syncNodeMaybeSendAppendEntries(SSyncNode* pSyncNode, const SRaftId* destRaftId, const SyncAppendEntries* pMsg) {
+  int32_t ret = 0;
+  if (syncNodeNeedSendAppendEntries(pSyncNode, destRaftId, pMsg)) {
+    ret = syncNodeSendAppendEntries(pSyncNode, destRaftId, pMsg);
+  }
+  return ret;
+}
+
 int32_t syncNodeAppendEntries(SSyncNode* pSyncNode, const SRaftId* destRaftId, const SyncAppendEntries* pMsg) {
   int32_t ret = 0;
   syncLogSendAppendEntries(pSyncNode, pMsg, "");