127 lines
3.9 KiB
C
127 lines
3.9 KiB
C
/*
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* Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
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*
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* This program is free software: you can use, redistribute, and/or modify
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* it under the terms of the GNU Affero General Public License, version 3
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* or later ("AGPL"), as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE.
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*
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* You should have received a copy of the GNU Affero General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#define _DEFAULT_SOURCE
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#include "syncElection.h"
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#include "syncMessage.h"
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#include "syncRaftCfg.h"
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#include "syncRaftStore.h"
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#include "syncUtil.h"
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#include "syncVoteMgr.h"
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// TLA+ Spec
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// RequestVote(i, j) ==
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// /\ state[i] = Candidate
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// /\ j \notin votesResponded[i]
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// /\ Send([mtype |-> RequestVoteRequest,
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// mterm |-> currentTerm[i],
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// mlastLogTerm |-> LastTerm(log[i]),
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// mlastLogIndex |-> Len(log[i]),
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// msource |-> i,
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// mdest |-> j])
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// /\ UNCHANGED <<serverVars, candidateVars, leaderVars, logVars>>
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static int32_t syncNodeRequestVotePeers(SSyncNode* pNode) {
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if (pNode->state != TAOS_SYNC_STATE_CANDIDATE) {
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sNTrace(pNode, "not candidate, stop elect");
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return 0;
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}
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int32_t ret = 0;
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for (int i = 0; i < pNode->peersNum; ++i) {
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if(pNode->peersNodeInfo[i].nodeRole == TAOS_SYNC_ROLE_LEARNER) continue;
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SRpcMsg rpcMsg = {0};
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ret = syncBuildRequestVote(&rpcMsg, pNode->vgId);
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if (ret < 0) {
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sError("vgId:%d, failed to build request-vote msg since %s", pNode->vgId, terrstr());
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continue;
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}
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SyncRequestVote* pMsg = rpcMsg.pCont;
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pMsg->srcId = pNode->myRaftId;
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pMsg->destId = pNode->peersId[i];
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pMsg->term = raftStoreGetTerm(pNode);
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ret = syncNodeGetLastIndexTerm(pNode, &pMsg->lastLogIndex, &pMsg->lastLogTerm);
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if (ret < 0) {
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sError("vgId:%d, failed to get index and term of last log since %s", pNode->vgId, terrstr());
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continue;
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}
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ret = syncNodeSendMsgById(&pNode->peersId[i], pNode, &rpcMsg);
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if (ret < 0) {
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sError("vgId:%d, failed to send msg to peerId:%" PRId64, pNode->vgId, pNode->peersId[i].addr);
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continue;
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}
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}
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return 0;
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}
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int32_t syncNodeElect(SSyncNode* pSyncNode) {
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if (pSyncNode->fsmState == SYNC_FSM_STATE_INCOMPLETE) {
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sNError(pSyncNode, "skip leader election due to incomplete fsm state");
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return -1;
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}
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sNInfo(pSyncNode, "begin election");
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pSyncNode->electNum++;
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int32_t ret = 0;
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if (pSyncNode->state == TAOS_SYNC_STATE_FOLLOWER) {
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syncNodeFollower2Candidate(pSyncNode);
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}
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if (pSyncNode->state != TAOS_SYNC_STATE_CANDIDATE) {
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sNError(pSyncNode, "not candidate, can not elect");
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return -1;
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}
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// start election
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raftStoreNextTerm(pSyncNode);
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raftStoreClearVote(pSyncNode);
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SyncTerm currentTerm = raftStoreGetTerm(pSyncNode);
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voteGrantedReset(pSyncNode->pVotesGranted, currentTerm);
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votesRespondReset(pSyncNode->pVotesRespond, currentTerm);
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syncNodeVoteForSelf(pSyncNode, currentTerm);
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if (voteGrantedMajority(pSyncNode->pVotesGranted)) {
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// only myself, to leader
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ASSERT(!pSyncNode->pVotesGranted->toLeader);
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syncNodeCandidate2Leader(pSyncNode);
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pSyncNode->pVotesGranted->toLeader = true;
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return ret;
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}
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if (pSyncNode->replicaNum == 1) {
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// only myself, to leader
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voteGrantedUpdate(pSyncNode->pVotesGranted, pSyncNode);
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votesRespondUpdate(pSyncNode->pVotesRespond, pSyncNode);
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pSyncNode->quorum = syncUtilQuorum(pSyncNode->raftCfg.cfg.replicaNum);
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syncNodeCandidate2Leader(pSyncNode);
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pSyncNode->pVotesGranted->toLeader = true;
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return ret;
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}
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ret = syncNodeRequestVotePeers(pSyncNode);
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ASSERT(ret == 0);
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syncNodeResetElectTimer(pSyncNode);
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return ret;
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}
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