diff --git a/include/libs/sync/sync.h b/include/libs/sync/sync.h
index b938bbba77..726fbc0621 100644
--- a/include/libs/sync/sync.h
+++ b/include/libs/sync/sync.h
@@ -32,7 +32,6 @@ typedef enum {
   TAOS_SYNC_ROLE_FOLLOWER = 0,
   TAOS_SYNC_ROLE_CANDIDATE = 1,
   TAOS_SYNC_ROLE_LEADER = 2,
-  TAOS_SYNC_ROLE_PRE_CANDIDATE = 3,
 } ESyncRole;
 
 typedef struct {
diff --git a/source/libs/sync/inc/raft.h b/source/libs/sync/inc/raft.h
index 702fcd00cf..44ee6a3b69 100644
--- a/source/libs/sync/inc/raft.h
+++ b/source/libs/sync/inc/raft.h
@@ -29,9 +29,16 @@ typedef struct RaftLeaderState {
   SSyncRaftProgress* progress;
 } RaftLeaderState;
 
+typedef struct RaftCandidateState {
+  /* votes results */
+  bool votes[TSDB_MAX_REPLICA];
+
+  /* true if in pre-vote phase */
+  bool inPreVote;
+} RaftCandidateState;
+
 typedef struct SSyncRaftIOMethods {
-
-
+  int (*send)(const SSyncMessage* pMsg, const SNodeInfo* pNode);
 } SSyncRaftIOMethods;
 
 typedef int   (*SyncRaftStepFp)(SSyncRaft* pRaft, const SSyncMessage* pMsg);
@@ -41,7 +48,10 @@ struct SSyncRaft {
   // owner sync node
   SSyncNode* pNode;
 
-  SSyncInfo info;
+  //SSyncInfo info;
+  SSyncFSM      fsm;
+  SSyncLogStore logStore;
+  SStateManager stateManager;
 
   SyncTerm term;
   SyncNodeId voteFor;
@@ -65,6 +75,8 @@ struct SSyncRaft {
    **/
 	bool pendingConf;
 
+  SSyncCluster cluster;
+
   ESyncRole state;
 
 	/** 
@@ -92,25 +104,22 @@ struct SSyncRaft {
 
   SSyncRaftIOMethods io;
 
-  RaftLeaderState leaderState;
-
-  SSyncRaftUnstableLog *log;
+  union {
+    RaftLeaderState leaderState;
+    RaftCandidateState candidateState;
+  };
+  
+  SSyncRaftLog *log;
 
   SyncRaftStepFp stepFp;
 
   SyncRaftTickFp tickFp;
 };
 
-typedef enum {
-  SYNC_RAFT_CAMPAIGN_PRE_ELECTION = 0,
-  SYNC_RAFT_CAMPAIGN_ELECTION = 1,
-} SyncRaftCampaignType;
-
 int32_t syncRaftStart(SSyncRaft* pRaft, const SSyncInfo* pInfo);
 int32_t syncRaftStep(SSyncRaft* pRaft, const SSyncMessage* pMsg);
 int32_t syncRaftTick(SSyncRaft* pRaft);
 
-
 void syncRaftBecomeFollower(SSyncRaft* pRaft, SyncTerm term, SyncNodeId leaderId);
 void syncRaftBecomePreCandidate(SSyncRaft* pRaft);
 void syncRaftBecomeCandidate(SSyncRaft* pRaft);
@@ -120,6 +129,6 @@ void syncRaftRandomizedElectionTimeout(SSyncRaft* pRaft);
 bool syncRaftIsPromotable(SSyncRaft* pRaft);
 bool syncRaftIsPastElectionTimeout(SSyncRaft* pRaft);
 int  syncRaftQuorum(SSyncRaft* pRaft);
-int  syncRaftNumOfGranted(SSyncRaft* pRaft, SyncNodeId id, RaftMessageType msgType, bool accept);
+int  syncRaftNumOfGranted(SSyncRaft* pRaft, SyncNodeId id, bool preVote, bool accept);
 
 #endif /* _TD_LIBS_SYNC_RAFT_H */
\ No newline at end of file
diff --git a/source/libs/sync/inc/raft_configuration.h b/source/libs/sync/inc/raft_configuration.h
new file mode 100644
index 0000000000..ed0cc33115
--- /dev/null
+++ b/source/libs/sync/inc/raft_configuration.h
@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <cli@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _TD_LIBS_SYNC_RAFT_CONFIGURATION_H
+#define _TD_LIBS_SYNC_RAFT_CONFIGURATION_H
+
+#include "sync.h"
+#include "sync_type.h"
+
+int syncRaftConfigurationIndexOfVoter(SSyncRaft *pRaft, SyncNodeId id);
+
+int syncRaftConfigurationVoterCount(SSyncRaft *pRaft);
+
+#endif  /* _TD_LIBS_SYNC_RAFT_CONFIGURATION_H */
\ No newline at end of file
diff --git a/source/libs/sync/inc/raft_log.h b/source/libs/sync/inc/raft_log.h
new file mode 100644
index 0000000000..7ffb946c82
--- /dev/null
+++ b/source/libs/sync/inc/raft_log.h
@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <cli@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _TD_LIBS_SYNC_RAFT_LOG_H
+#define _TD_LIBS_SYNC_RAFT_LOG_H
+
+#include "sync.h"
+#include "sync_type.h"
+
+struct SSyncRaftLog {
+  SyncIndex uncommittedConfigIndex;
+
+  SyncIndex commitIndex;
+
+  SyncIndex appliedIndex;
+
+
+};
+
+SSyncRaftLog* syncRaftLogOpen();
+
+SyncIndex syncRaftLogLastIndex(SSyncRaftLog* pLog);
+
+SyncTerm syncRaftLogLastTerm(SSyncRaftLog* pLog);
+
+int syncRaftLogNumOfPendingConf(SSyncRaftLog* pLog);
+
+bool syncRaftHasUnappliedLog(SSyncRaftLog* pLog);
+
+#endif  /* _TD_LIBS_SYNC_RAFT_LOG_H */
diff --git a/source/libs/sync/inc/raft_message.h b/source/libs/sync/inc/raft_message.h
index 71fe37bebd..d4736d6169 100644
--- a/source/libs/sync/inc/raft_message.h
+++ b/source/libs/sync/inc/raft_message.h
@@ -35,8 +35,7 @@ typedef enum RaftMessageType {
   RAFT_MSG_VOTE = 3,
   RAFT_MSG_VOTE_RESP = 4,
 
-  RAFT_MSG_PRE_VOTE = 5,
-  RAFT_MSG_PRE_VOTE_RESP = 6,
+
 } RaftMessageType;
 
 typedef struct RaftMsgInternal_Prop {
@@ -49,13 +48,21 @@ typedef struct RaftMsgInternal_Election {
 
 } RaftMsgInternal_Election;
 
-typedef struct RaftMsg_PreVoteResp {
+typedef struct RaftMsg_Vote {
+  SyncRaftCampaignType cType;
+  SyncIndex lastIndex;
+  SyncTerm lastTerm;
+} RaftMsg_Vote;
+
+typedef struct RaftMsg_VoteResp {
   bool reject;
-} RaftMsg_PreVoteResp;
+  SyncRaftCampaignType cType;
+} RaftMsg_VoteResp;
 
 typedef struct SSyncMessage {
   RaftMessageType msgType;
   SyncTerm term;
+  SyncGroupId groupId;
   SyncNodeId from;
   SyncNodeId to;
 
@@ -64,7 +71,8 @@ typedef struct SSyncMessage {
 
     RaftMsgInternal_Election election;
 
-    RaftMsg_PreVoteResp preVoteResp;
+    RaftMsg_Vote vote;
+    RaftMsg_VoteResp voteResp;
   };
 } SSyncMessage;
 
@@ -95,14 +103,39 @@ static FORCE_INLINE SSyncMessage* syncInitElectionMsg(SSyncMessage* pMsg, SyncNo
   return pMsg;
 }
 
+static FORCE_INLINE SSyncMessage* syncNewVoteMsg(SyncGroupId groupId, SyncNodeId from, SyncNodeId to,
+                                                SyncTerm term, SyncRaftCampaignType cType, 
+                                                SyncIndex lastIndex, SyncTerm lastTerm) {
+  SSyncMessage* pMsg = (SSyncMessage*)malloc(sizeof(SSyncMessage));
+  if (pMsg == NULL) {
+    return NULL;
+  }
+  *pMsg = (SSyncMessage) {
+    .groupId = groupId,
+    .from = from,
+    .to = to,
+    .term = term,
+    .vote = (RaftMsg_Vote) {
+      .cType = cType,
+      .lastIndex = lastIndex,
+      .lastTerm = lastTerm,
+    },
+  };
+
+  return pMsg;
+}
+
 static FORCE_INLINE bool syncIsInternalMsg(RaftMessageType msgType) {
   return msgType == RAFT_MSG_INTERNAL_PROP ||
          msgType == RAFT_MSG_INTERNAL_ELECTION;
 }
 
-static FORCE_INLINE RaftMessageType SyncRaftVoteRespMsgType(RaftMessageType msgType) {
-  if (msgType == RAFT_MSG_VOTE) return RAFT_MSG_PRE_VOTE_RESP;
-  return RAFT_MSG_PRE_VOTE_RESP;
+static FORCE_INLINE bool syncIsPreVoteRespMsg(SSyncMessage* pMsg) {
+  return pMsg->msgType == RAFT_MSG_VOTE_RESP && pMsg->voteResp.cType == SYNC_RAFT_CAMPAIGN_PRE_ELECTION;
+}
+
+static FORCE_INLINE bool syncIsPreVoteMsg(SSyncMessage* pMsg) {
+  return pMsg->msgType == RAFT_MSG_VOTE && pMsg->voteResp.cType == SYNC_RAFT_CAMPAIGN_PRE_ELECTION;
 }
 
 void syncFreeMessage(const SSyncMessage* pMsg);
diff --git a/source/libs/sync/inc/raft_unstable_log.h b/source/libs/sync/inc/raft_unstable_log.h
index 0c9957cb90..0748a425a1 100644
--- a/source/libs/sync/inc/raft_unstable_log.h
+++ b/source/libs/sync/inc/raft_unstable_log.h
@@ -41,7 +41,7 @@ struct SSyncRaftUnstableLog {
 /**
  * return index of last in memory log, return 0 if log is empty
  **/
-SyncIndex syncRaftLogLastIndex(SSyncRaftUnstableLog* pLog);
+//SyncIndex syncRaftLogLastIndex(SSyncRaftUnstableLog* pLog);
 
 #if 0
 void raftLogInit(RaftLog* pLog);
diff --git a/source/libs/sync/inc/sync_type.h b/source/libs/sync/inc/sync_type.h
index 2c9f24287a..4343e607cb 100644
--- a/source/libs/sync/inc/sync_type.h
+++ b/source/libs/sync/inc/sync_type.h
@@ -18,10 +18,10 @@
 
 typedef int32_t SyncTime;
 
-typedef struct SSyncRaftUnstableLog SSyncRaftUnstableLog;
-
 typedef struct SSyncRaft SSyncRaft;
 
+typedef struct SSyncRaftLog SSyncRaftLog;
+
 #ifndef MIN
 #define MIN(x, y) (((x) < (y)) ? (x) : (y))
 #endif
@@ -30,4 +30,10 @@ typedef struct SSyncRaft SSyncRaft;
 #define MAX(x, y) (((x) > (y)) ? (x) : (y))
 #endif
 
+typedef enum {
+  SYNC_RAFT_CAMPAIGN_PRE_ELECTION = 0,
+  SYNC_RAFT_CAMPAIGN_ELECTION = 1,
+  SYNC_RAFT_CAMPAIGN_TRANSFER = 3,
+} SyncRaftCampaignType;
+
 #endif  /* _TD_LIBS_SYNC_TYPE_H */
diff --git a/source/libs/sync/src/raft.c b/source/libs/sync/src/raft.c
index 87750eca9e..a6e013758e 100644
--- a/source/libs/sync/src/raft.c
+++ b/source/libs/sync/src/raft.c
@@ -14,6 +14,7 @@
  */
 
 #include "raft.h"
+#include "raft_configuration.h"
 #include "syncInt.h"
 
 #define RAFT_READ_LOG_MAX_NUM 100
@@ -22,6 +23,7 @@ static bool preHandleMessage(SSyncRaft* pRaft, const SSyncMessage* pMsg);
 static bool preHandleNewTermMessage(SSyncRaft* pRaft, const SSyncMessage* pMsg);
 static bool preHandleOldTermMessage(SSyncRaft* pRaft, const SSyncMessage* pMsg);
 
+static int convertClear(SSyncRaft* pRaft);
 static int stepFollower(SSyncRaft* pRaft, const SSyncMessage* pMsg);
 static int stepCandidate(SSyncRaft* pRaft, const SSyncMessage* pMsg);
 static int stepLeader(SSyncRaft* pRaft, const SSyncMessage* pMsg);
@@ -45,11 +47,18 @@ int32_t syncRaftStart(SSyncRaft* pRaft, const SSyncInfo* pInfo) {
   
   memset(pRaft, 0, sizeof(SSyncRaft));
 
-  memcpy(&pRaft->info, pInfo, sizeof(SSyncInfo));
-  stateManager = &(pRaft->info.stateManager);
-  logStore = &(pRaft->info.logStore);
-  fsm = &(pRaft->info.fsm);
+  memcpy(&pRaft->fsm, &pInfo->fsm, sizeof(SSyncFSM));
+  memcpy(&pRaft->logStore, &pInfo->logStore, sizeof(SSyncLogStore));
+  memcpy(&pRaft->stateManager, &pInfo->stateManager, sizeof(SStateManager));
 
+  stateManager = &(pRaft->stateManager);
+  logStore = &(pRaft->logStore);
+  fsm = &(pRaft->fsm);
+
+  // open raft log
+  if ((pRaft->log = syncRaftLogOpen()) == NULL) {
+    return -1;
+  }
   // read server state
   if (stateManager->readServerState(stateManager, &serverState) != 0) {
     syncError("readServerState for vgid %d fail", pInfo->vgId);
@@ -79,7 +88,8 @@ int32_t syncRaftStart(SSyncRaft* pRaft, const SSyncInfo* pInfo) {
 
   syncRaftBecomeFollower(pRaft, pRaft->term, SYNC_NON_NODE_ID);
 
-  syncInfo("restore vgid %d state: snapshot index success", pInfo->vgId);
+  syncInfo("[%d:%d] restore vgid %d state: snapshot index success", 
+    pRaft->selfGroupId, pRaft->selfId, pInfo->vgId);
   return 0;
 }
 
@@ -95,7 +105,7 @@ int32_t syncRaftStep(SSyncRaft* pRaft, const SSyncMessage* pMsg) {
   RaftMessageType msgType = pMsg->msgType;
   if (msgType == RAFT_MSG_INTERNAL_ELECTION) {
     syncRaftHandleElectionMessage(pRaft, pMsg);
-  } else if (msgType == RAFT_MSG_VOTE || msgType == RAFT_MSG_PRE_VOTE) {
+  } else if (msgType == RAFT_MSG_VOTE) {
 
   } else {
     pRaft->stepFp(pRaft, pMsg);
@@ -125,11 +135,13 @@ void syncRaftBecomePreCandidate(SSyncRaft* pRaft) {
    **/
   pRaft->stepFp = stepCandidate;
   pRaft->tickFp = tickElection;
-  pRaft->state  = TAOS_SYNC_ROLE_PRE_CANDIDATE;
+  pRaft->state  = TAOS_SYNC_ROLE_CANDIDATE;
+  pRaft->candidateState.inPreVote = true;
   syncInfo("[%d:%d] became pre-candidate at term %d" PRId64 "", pRaft->selfGroupId, pRaft->selfId, pRaft->term);
 }
 
 void syncRaftBecomeCandidate(SSyncRaft* pRaft) {
+  pRaft->candidateState.inPreVote = false;
   pRaft->stepFp = stepCandidate;
   // become candidate make term+1
   resetRaft(pRaft, pRaft->term + 1);
@@ -157,9 +169,7 @@ void syncRaftRandomizedElectionTimeout(SSyncRaft* pRaft) {
 }
 
 bool syncRaftIsPromotable(SSyncRaft* pRaft) {
-  return pRaft->info.syncCfg.selfIndex >= 0 && 
-         pRaft->info.syncCfg.selfIndex < pRaft->info.syncCfg.replica &&
-         pRaft->selfId != SYNC_NON_NODE_ID;
+  return pRaft->selfId != SYNC_NON_NODE_ID;
 }
 
 bool syncRaftIsPastElectionTimeout(SSyncRaft* pRaft) {
@@ -167,17 +177,29 @@ bool syncRaftIsPastElectionTimeout(SSyncRaft* pRaft) {
 }
 
 int syncRaftQuorum(SSyncRaft* pRaft) {
-  return pRaft->leaderState.nProgress / 2 + 1;
+  return pRaft->cluster.replica / 2 + 1;
 }
 
-int syncRaftNumOfGranted(SSyncRaft* pRaft, SyncNodeId id, RaftMessageType msgType, bool accept) {
+int syncRaftNumOfGranted(SSyncRaft* pRaft, SyncNodeId id, bool preVote, bool accept) {
   if (accept) {
-
+    syncInfo("[%d:%d] received (pre-vote %d) from %d at term %" PRId64 "", 
+      pRaft->selfGroupId, pRaft->selfId, preVote, id, pRaft->term);
   } else {
-
+    syncInfo("[%d:%d] received rejection from %d at term %" PRId64 "", 
+      pRaft->selfGroupId, pRaft->selfId, id, pRaft->term);
   }
 
+  int voteIndex = syncRaftConfigurationIndexOfVoter(pRaft, id);
+  assert(voteIndex < pRaft->cluster.replica && voteIndex >= 0);
 
+  pRaft->candidateState.votes[voteIndex] = accept;
+  int granted = 0;
+  int i;
+  for (i = 0; i < pRaft->cluster.replica; ++i) {
+    if (pRaft->candidateState.votes[i]) granted++;
+  }
+
+  return granted;
 }
 
 /**
@@ -201,13 +223,13 @@ static bool preHandleNewTermMessage(SSyncRaft* pRaft, const SSyncMessage* pMsg)
   SyncNodeId leaderId = pMsg->from;
   RaftMessageType msgType = pMsg->msgType;
 
-  if (msgType == RAFT_MSG_VOTE || msgType == RAFT_MSG_PRE_VOTE) {
+  if (msgType == RAFT_MSG_VOTE) {
     leaderId = SYNC_NON_NODE_ID;
   }
 
-  if (msgType == RAFT_MSG_PRE_VOTE) {
+  if (syncIsPreVoteMsg(pMsg)) {
     // Never change our term in response to a PreVote
-  } else if (msgType == RAFT_MSG_PRE_VOTE_RESP && !pMsg->preVoteResp.reject) {
+  } else if (syncIsPreVoteRespMsg(pMsg) && !pMsg->voteResp.reject) {
 		/**
      * We send pre-vote requests with a term in our future. If the
 		 * pre-vote is granted, we will increment our term when we get a
@@ -216,8 +238,8 @@ static bool preHandleNewTermMessage(SSyncRaft* pRaft, const SSyncMessage* pMsg)
 		 * term.
      **/
   } else {
-    syncInfo("%d [term:%" PRId64 "] received a %d message with higher term from %d [term:%" PRId64 "]",
-      pRaft->selfId, pRaft->term, msgType, pMsg->from, pMsg->term);
+    syncInfo("[%d:%d] [term:%" PRId64 "] received a %d message with higher term from %d [term:%" PRId64 "]",
+      pRaft->selfGroupId, pRaft->selfId, pRaft->term, msgType, pMsg->from, pMsg->term);
     syncRaftBecomeFollower(pRaft, pMsg->term, leaderId);
   }
 
@@ -230,15 +252,23 @@ static bool preHandleOldTermMessage(SSyncRaft* pRaft, const SSyncMessage* pMsg)
   return true;
 }
 
+static int convertClear(SSyncRaft* pRaft) {
+
+}
+
 static int stepFollower(SSyncRaft* pRaft, const SSyncMessage* pMsg) {
+  convertClear(pRaft);
   return 0;
 }
 
 static int stepCandidate(SSyncRaft* pRaft, const SSyncMessage* pMsg) {
+  convertClear(pRaft);
+  memset(pRaft->candidateState.votes, 0, sizeof(bool) * TSDB_MAX_REPLICA);
   return 0;
 }
 
 static int stepLeader(SSyncRaft* pRaft, const SSyncMessage* pMsg) {
+  convertClear(pRaft);
   return 0;
 }
 
diff --git a/source/libs/sync/src/raft_configuration.c b/source/libs/sync/src/raft_configuration.c
new file mode 100644
index 0000000000..6f3a27e7c0
--- /dev/null
+++ b/source/libs/sync/src/raft_configuration.c
@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <cli@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "raft_configuration.h"
+#include "raft.h"
+
+int syncRaftConfigurationIndexOfVoter(SSyncRaft *pRaft, SyncNodeId id) {
+  return (int)(id);
+}
+
+int syncRaftConfigurationVoterCount(SSyncRaft *pRaft) {
+  return pRaft->cluster.replica;
+}
\ No newline at end of file
diff --git a/source/libs/sync/src/raft_handle_election_message.c b/source/libs/sync/src/raft_handle_election_message.c
index 2586cd918d..0d2004dec2 100644
--- a/source/libs/sync/src/raft_handle_election_message.c
+++ b/source/libs/sync/src/raft_handle_election_message.c
@@ -25,34 +25,41 @@ void syncRaftHandleElectionMessage(SSyncRaft* pRaft, const SSyncMessage* pMsg) {
     return;
   }
 
-  // TODO: is there pending uncommitted config?
+  // if there is pending uncommitted config,cannot campaign
+  if (syncRaftLogNumOfPendingConf(pRaft->log) > 0 && syncRaftHasUnappliedLog(pRaft->log)) {
+    syncWarn("[%d:%d] cannot campaign at term %" PRId64 " since there are still pending configuration changes to apply",
+      pRaft->selfGroupId, pRaft->selfId, pRaft->term);
+    return;
+  }
 
   syncInfo("[%d:%d] is starting a new election at term %" PRId64 "", pRaft->selfGroupId, pRaft->selfId, pRaft->term);
 
   if (pRaft->preVote) {
-
+    campaign(pRaft, SYNC_RAFT_CAMPAIGN_PRE_ELECTION);
   } else {
-
+    campaign(pRaft, SYNC_RAFT_CAMPAIGN_ELECTION);
   }
 }
 
 static void campaign(SSyncRaft* pRaft, SyncRaftCampaignType cType) {
   SyncTerm term;
+  bool preVote;
   RaftMessageType voteMsgType;
 
   if (cType == SYNC_RAFT_CAMPAIGN_PRE_ELECTION) {
     syncRaftBecomePreCandidate(pRaft);
-    voteMsgType = RAFT_MSG_PRE_VOTE;
+    preVote = true;
     // PreVote RPCs are sent for the next term before we've incremented r.Term.
     term = pRaft->term + 1;
   } else {
     syncRaftBecomeCandidate(pRaft);
     voteMsgType = RAFT_MSG_VOTE;
     term = pRaft->term;
+    preVote = false;
   }
 
   int quorum = syncRaftQuorum(pRaft);
-  int granted = syncRaftNumOfGranted(pRaft, pRaft->selfId, SyncRaftVoteRespMsgType(voteMsgType), true);
+  int granted = syncRaftNumOfGranted(pRaft, pRaft->selfId, preVote, true);
   if (quorum <= granted) {
 		/**
      * We won the election after voting for ourselves (which must mean that
@@ -67,5 +74,25 @@ static void campaign(SSyncRaft* pRaft, SyncRaftCampaignType cType) {
   }
 
   // broadcast vote message to other peers
+  int i;
+  SyncIndex lastIndex = syncRaftLogLastIndex(pRaft->log);
+  SyncTerm lastTerm = syncRaftLogLastTerm(pRaft->log);
+  for (i = 0; i < pRaft->cluster.replica; ++i) {
+    if (i == pRaft->cluster.selfIndex) {
+      continue;
+    }
 
+    SyncNodeId nodeId = pRaft->cluster.nodeInfo[i].nodeId;
+
+    SSyncMessage* pMsg = syncNewVoteMsg(pRaft->selfGroupId, pRaft->selfId, nodeId, term, cType, lastIndex, lastTerm);
+    if (pMsg == NULL) {
+      continue;
+    }
+
+    syncInfo("[%d:%d] [logterm: %" PRId64 ", index: %d] sent %d request to %d at term %" PRId64 "", 
+      pRaft->selfGroupId, pRaft->selfId, lastTerm, 
+      lastIndex, voteMsgType, nodeId, pRaft->term);
+
+    pRaft->io.send(pMsg, &(pRaft->cluster.nodeInfo[i]));
+  }
 }
\ No newline at end of file
diff --git a/source/libs/sync/src/raft_log.c b/source/libs/sync/src/raft_log.c
new file mode 100644
index 0000000000..46c4e4b304
--- /dev/null
+++ b/source/libs/sync/src/raft_log.c
@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <cli@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "raft_log.h"
+
+SSyncRaftLog* syncRaftLogOpen() {
+  return NULL;
+}
+
+SyncIndex syncRaftLogLastIndex(SSyncRaftLog* pLog) {
+  return 0;
+}
+
+SyncTerm syncRaftLogLastTerm(SSyncRaftLog* pLog) {
+  return 0;
+}
+
+int syncRaftLogNumOfPendingConf(SSyncRaftLog* pLog) {
+  return 0;
+}
+
+bool syncRaftHasUnappliedLog(SSyncRaftLog* pLog) {
+  return pLog->commitIndex > pLog->appliedIndex;
+}
\ No newline at end of file
diff --git a/source/libs/sync/src/raft_unstable_log.c b/source/libs/sync/src/raft_unstable_log.c
index 4735242d3c..e798e20662 100644
--- a/source/libs/sync/src/raft_unstable_log.c
+++ b/source/libs/sync/src/raft_unstable_log.c
@@ -16,6 +16,8 @@
 #include "sync.h"
 #include "raft_unstable_log.h"
 
+/*
 SyncIndex syncRaftLogLastIndex(SSyncRaftUnstableLog* pLog) {
   return 0;
-}
\ No newline at end of file
+}
+*/
\ No newline at end of file