本次进行主从切换及删除节点的操作。
1. 主从切换
1.1 查询当前节点信息及状态
使用rs.status()命令可以查看到当前副本集各节点信息及角色
节点id | 节点 | 角色 |
node0 | 192.168.56.198:27017 | PRIMARY |
node1 | 192.168.56.199:27018 | ARBITER |
node2 | 192.168.56.197:27017 | SECONDARY |
node3 | 192.168.56.199:27017 | SECONDARY |
test12:PRIMARY> rs.status()
{
"set" : "test12",
"date" : ISODate("2021-12-16T13:45:28.261Z"),
"myState" : 1,
"term" : NumberLong(3),
"syncingTo" : "",
"syncSourceHost" : "",
"syncSourceId" : -1,
"heartbeatIntervalMillis" : NumberLong(2000),
"majorityVoteCount" : 3,
"writeMajorityCount" : 3,
"optimes" : {
"lastCommittedOpTime" : {
"ts" : Timestamp(1639662318, 1),
"t" : NumberLong(3)
},
"lastCommittedWallTime" : ISODate("2021-12-16T13:45:18.626Z"),
"readConcernMajorityOpTime" : {
"ts" : Timestamp(1639662318, 1),
"t" : NumberLong(3)
},
"readConcernMajorityWallTime" : ISODate("2021-12-16T13:45:18.626Z"),
"appliedOpTime" : {
"ts" : Timestamp(1639662318, 1),
"t" : NumberLong(3)
},
"durableOpTime" : {
"ts" : Timestamp(1639662318, 1),
"t" : NumberLong(3)
},
"lastAppliedWallTime" : ISODate("2021-12-16T13:45:18.626Z"),
"lastDurableWallTime" : ISODate("2021-12-16T13:45:18.626Z")
},
"lastStableRecoveryTimestamp" : Timestamp(1639662308, 1),
"lastStableCheckpointTimestamp" : Timestamp(1639662308, 1),
"electionCandidateMetrics" : {
"lastElectionReason" : "priorityTakeover",
"lastElectionDate" : ISODate("2021-12-14T15:24:57.309Z"),
"electionTerm" : NumberLong(3),
"lastCommittedOpTimeAtElection" : {
"ts" : Timestamp(1639495485, 1),
"t" : NumberLong(2)
},
"lastSeenOpTimeAtElection" : {
"ts" : Timestamp(1639495485, 1),
"t" : NumberLong(2)
},
"numVotesNeeded" : 3,
"priorityAtElection" : 15,
"electionTimeoutMillis" : NumberLong(10000),
"priorPrimaryMemberId" : 3,
"numCatchUpOps" : NumberLong(0),
"newTermStartDate" : ISODate("2021-12-14T15:24:57.321Z"),
"wMajorityWriteAvailabilityDate" : ISODate("2021-12-14T15:24:58.285Z")
},
"electionParticipantMetrics" : {
"votedForCandidate" : true,
"electionTerm" : NumberLong(2),
"lastVoteDate" : ISODate("2021-12-14T10:36:13.063Z"),
"electionCandidateMemberId" : 3,
"voteReason" : "",
"lastAppliedOpTimeAtElection" : {
"ts" : Timestamp(1639478166, 1),
"t" : NumberLong(1)
},
"maxAppliedOpTimeInSet" : {
"ts" : Timestamp(1639478166, 1),
"t" : NumberLong(1)
},
"priorityAtElection" : 1
},
"members" : [
{
"_id" : 0,
"name" : "192.168.56.198:27017",
"health" : 1,
"state" : 1,
"stateStr" : "PRIMARY",
"uptime" : 186852,
"optime" : {
"ts" : Timestamp(1639662318, 1),
"t" : NumberLong(3)
},
"optimeDate" : ISODate("2021-12-16T13:45:18Z"),
"syncingTo" : "",
"syncSourceHost" : "",
"syncSourceId" : -1,
"infoMessage" : "",
"electionTime" : Timestamp(1639495497, 1),
"electionDate" : ISODate("2021-12-14T15:24:57Z"),
"configVersion" : 7,
"self" : true,
"lastHeartbeatMessage" : ""
},
{
"_id" : 1,
"name" : "192.168.56.199:27018",
"health" : 1,
"state" : 7,
"stateStr" : "ARBITER",
"uptime" : 186375,
"lastHeartbeat" : ISODate("2021-12-16T13:45:27.183Z"),
"lastHeartbeatRecv" : ISODate("2021-12-16T13:45:26.984Z"),
"pingMs" : NumberLong(0),
"lastHeartbeatMessage" : "",
"syncingTo" : "",
"syncSourceHost" : "",
"syncSourceId" : -1,
"infoMessage" : "",
"configVersion" : 7
},
{
"_id" : 2,
"name" : "192.168.56.197:27017",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 185329,
"optime" : {
"ts" : Timestamp(1639662318, 1),
"t" : NumberLong(3)
},
"optimeDurable" : {
"ts" : Timestamp(1639662318, 1),
"t" : NumberLong(3)
},
"optimeDate" : ISODate("2021-12-16T13:45:18Z"),
"optimeDurableDate" : ISODate("2021-12-16T13:45:18Z"),
"lastHeartbeat" : ISODate("2021-12-16T13:45:27.463Z"),
"lastHeartbeatRecv" : ISODate("2021-12-16T13:45:26.387Z"),
"pingMs" : NumberLong(1),
"lastHeartbeatMessage" : "",
"syncingTo" : "192.168.56.198:27017",
"syncSourceHost" : "192.168.56.198:27017",
"syncSourceId" : 0,
"infoMessage" : "",
"configVersion" : 7
},
{
"_id" : 3,
"name" : "192.168.56.199:27017",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 12079,
"optime" : {
"ts" : Timestamp(1639662318, 1),
"t" : NumberLong(3)
},
"optimeDurable" : {
"ts" : Timestamp(1639662318, 1),
"t" : NumberLong(3)
},
"optimeDate" : ISODate("2021-12-16T13:45:18Z"),
"optimeDurableDate" : ISODate("2021-12-16T13:45:18Z"),
"lastHeartbeat" : ISODate("2021-12-16T13:45:28.253Z"),
"lastHeartbeatRecv" : ISODate("2021-12-16T13:45:27.555Z"),
"pingMs" : NumberLong(0),
"lastHeartbeatMessage" : "",
"syncingTo" : "192.168.56.198:27017",
"syncSourceHost" : "192.168.56.198:27017",
"syncSourceId" : 0,
"infoMessage" : "",
"configVersion" : 7
}
],
"ok" : 1,
"$clusterTime" : {
"clusterTime" : Timestamp(1639662318, 1),
"signature" : {
"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
"keyId" : NumberLong(0)
}
},
"operationTime" : Timestamp(1639662318, 1)
}
1.2 切换主库
将主库切换至node3节点，具体步骤为：
查看当前配置
调整node3节点的权重
重新加载配置
因默认情况下，各节点的权重都为1，因此可以调整需要切换为主库的节点的权重为较大的值（建议超过节点数）
test12:PRIMARY> rs.config()
{
"_id" : "test12",
"version" : 9,
"protocolVersion" : NumberLong(1),
"writeConcernMajorityJournalDefault" : true,
"members" : [
{
"_id" : 0,
"host" : "192.168.56.198:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 1,
"tags" : {
},
"slaveDelay" : NumberLong(0),
"votes" : 1
},
{
"_id" : 1,
"host" : "192.168.56.199:27018",
"arbiterOnly" : true,
"buildIndexes" : true,
"hidden" : false,
"priority" : 0,
"tags" : {
},
"slaveDelay" : NumberLong(0),
"votes" : 1
},
{
"_id" : 2,
"host" : "192.168.56.197:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 1,
"tags" : {
},
"slaveDelay" : NumberLong(0),
"votes" : 1
},
{
"_id" : 3,
"host" : "192.168.56.199:27017",
"arbiterOnly" : false,
"buildIndexes" : true,
"hidden" : false,
"priority" : 1,
"tags" : {
},
"slaveDelay" : NumberLong(0),
"votes" : 1
}
],
"settings" : {
"chainingAllowed" : true,
"heartbeatIntervalMillis" : 2000,
"heartbeatTimeoutSecs" : 10,
"electionTimeoutMillis" : 10000,
"catchUpTimeoutMillis" : -1,
"catchUpTakeoverDelayMillis" : 30000,
"getLastErrorModes" : {
},
"getLastErrorDefaults" : {
"w" : 1,
"wtimeout" : 0
},
"replicaSetId" : ObjectId("61b86af0a21015e69623e18d")
}
}
将node3的节点的权重改为10
var cfg = rs.conf()
cfg.members[3].priority = 10
重新加载配置，选主
rs.reconfig(cfg)
通常1分钟内完成切换。
PS：也可以通过rs.stepDown()
PRIMARY> rs.stepDown() //rs.stepDown(30) 单位：S
这个命令会让primary降级为Secondary节点，并维持60s，如果这段时间内没有新的primary被选举出来，这个节点可以要求重新进行选举
2. 剔除节点
剔除的节点为SECONDARY或ARBITER，可以执行通过rs.remove() 命令剔除对应节点，如为PRIMARY节点，则先进行主从切换，再剔除。
test12:PRIMARY> rs.remove("192.168.56.199:27018")
{
"ok" : 1,
"$clusterTime" : {
"clusterTime" : Timestamp(1639683041, 1),
"signature" : {
"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
"keyId" : NumberLong(0)
}
},
"operationTime" : Timestamp(1639683041, 1)
}
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