114 lines
3.9 KiB
C
114 lines
3.9 KiB
C
/*
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* Copyright (c) 2019 TAOS Data, Inc. <cli@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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#include "syncInt.h"
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#include "raft.h"
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#include "raft_log.h"
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#include "raft_message.h"
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#include "sync_raft_progress_tracker.h"
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void syncRaftStartElection(SSyncRaft* pRaft, ESyncRaftElectionType cType) {
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if (pRaft->state == TAOS_SYNC_STATE_LEADER) {
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syncDebug("[%d:%d] ignoring RAFT_MSG_INTERNAL_ELECTION because already leader", pRaft->selfGroupId, pRaft->selfId);
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return;
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}
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if (!syncRaftIsPromotable(pRaft)) {
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syncWarn("[%d:%d] is unpromotable and can not syncRaftCampaign", pRaft->selfGroupId, pRaft->selfId);
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return;
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}
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// if there is pending uncommitted config,cannot start election
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if (syncRaftLogNumOfPendingConf(pRaft->log) > 0 && syncRaftHasUnappliedLog(pRaft->log)) {
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syncWarn("[%d:%d] cannot syncRaftStartElection at term %" PRId64 " since there are still pending configuration changes to apply",
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pRaft->selfGroupId, pRaft->selfId, pRaft->term);
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return;
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}
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syncInfo("[%d:%d] is starting a new election at term %" PRId64 "", pRaft->selfGroupId, pRaft->selfId, pRaft->term);
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syncRaftCampaign(pRaft, cType);
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}
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// syncRaftCampaign transitions the raft instance to candidate state. This must only be
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// called after verifying that this is a legitimate transition.
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void syncRaftCampaign(SSyncRaft* pRaft, ESyncRaftElectionType cType) {
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bool preVote;
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SyncTerm term;
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if (syncRaftIsPromotable(pRaft)) {
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syncDebug("[%d:%d] is unpromotable; syncRaftCampaign() should have been called", pRaft->selfGroupId, pRaft->selfId);
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return;
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}
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if (cType == SYNC_RAFT_CAMPAIGN_PRE_ELECTION) {
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syncRaftBecomePreCandidate(pRaft);
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preVote = true;
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// PreVote RPCs are sent for the next term before we've incremented r.Term.
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term = pRaft->term + 1;
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} else {
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syncRaftBecomeCandidate(pRaft);
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term = pRaft->term;
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preVote = false;
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}
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int quorum = syncRaftQuorum(pRaft);
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ESyncRaftVoteResult result = syncRaftPollVote(pRaft, pRaft->selfId, preVote, true, NULL, NULL);
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if (result == SYNC_RAFT_VOTE_WON) {
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// We won the election after voting for ourselves (which must mean that
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// this is a single-node cluster). Advance to the next state.
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if (cType == SYNC_RAFT_CAMPAIGN_PRE_ELECTION) {
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syncRaftStartElection(pRaft, SYNC_RAFT_CAMPAIGN_ELECTION);
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} else {
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syncRaftBecomeLeader(pRaft);
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}
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return;
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}
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// broadcast vote message to other peers
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int i;
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SyncIndex lastIndex = syncRaftLogLastIndex(pRaft->log);
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SyncTerm lastTerm = syncRaftLogLastTerm(pRaft->log);
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SSyncRaftNodeMap nodeMap;
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syncRaftJointConfigIDs(&pRaft->tracker->config.voters, &nodeMap);
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SyncNodeId *pNodeId = NULL;
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while (!syncRaftIterateNodeMap(&nodeMap, pNodeId)) {
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SyncNodeId nodeId = *pNodeId;
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if (nodeId == SYNC_NON_NODE_ID) {
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continue;
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}
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if (nodeId == pRaft->selfId) {
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continue;
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}
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SNodeInfo* pNode = syncRaftGetNodeById(pRaft, nodeId);
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if (pNode == NULL) {
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continue;
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}
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SSyncMessage* pMsg = syncNewVoteMsg(pRaft->selfGroupId, pRaft->selfId,
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term, cType, lastIndex, lastTerm);
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if (pMsg == NULL) {
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continue;
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}
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syncInfo("[%d:%d] [logterm: %" PRId64 ", index: %" PRId64 "] sent vote request to %d at term %" PRId64 "",
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pRaft->selfGroupId, pRaft->selfId, lastTerm,
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lastIndex, nodeId, pRaft->term);
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pRaft->io.send(pMsg, pNode);
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}
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} |