mongodb副本集主从切换
前文已有mongodb副本集搭建及添加节点的记录
mongodb 4.0副本集搭建
mongodb副本集添加节点
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(), "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" : , "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(), "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" : , "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(), "lastHeartbeatMessage" : "", "syncingTo" : "192.168.56.198:27017", "syncSourceHost" : "192.168.56.198:27017", "syncSourceId" : , "infoMessage" : "", "configVersion" : 7 } ], "ok" : 1, "$clusterTime" : { "clusterTime" : Timestamp(1639662318, 1), "signature" : { "hash" : BinData(,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="), "keyId" : NumberLong() } }, "operationTime" : Timestamp(1639662318, 1)}
1.2 切换主库
将主库切换至node3节点，具体步骤为：
查看当前配置
调整node3节点的权重
重新加载配置
因默认情况下，各节点的权重都为1，因此可以调整需要切换为主库的节点的权重为较大的值（建议超过节点数）
test12:PRIMARY> rs.config(){ "_id" : "test12", "version" : 9, "protocolVersion" : NumberLong(1), "writeConcernMajorityJournalDefault" : true, "members" : [ { "_id" : , "host" : "192.168.56.198:27017", "arbiterOnly" : false, "buildIndexes" : true, "hidden" : false, "priority" : 1, "tags" : {
}, "slaveDelay" : NumberLong(), "votes" : 1 }, { "_id" : 1, "host" : "192.168.56.199:27018", "arbiterOnly" : true, "buildIndexes" : true, "hidden" : false, "priority" : , "tags" : {
}, "slaveDelay" : NumberLong(), "votes" : 1 }, { "_id" : 2, "host" : "192.168.56.197:27017", "arbiterOnly" : false, "buildIndexes" : true, "hidden" : false, "priority" : 1, "tags" : {
}, "slaveDelay" : NumberLong(), "votes" : 1 }, { "_id" : 3, "host" : "192.168.56.199:27017", "arbiterOnly" : false, "buildIndexes" : true, "hidden" : false, "priority" : 1, "tags" : {
}, "slaveDelay" : NumberLong(), "votes" : 1 } ], "settings" : { "chainingAllowed" : true, "heartbeatIntervalMillis" : 2000, "heartbeatTimeoutSecs" : 10, "electionTimeoutMillis" : 10000, "catchUpTimeoutMillis" : -1, "catchUpTakeoverDelayMillis" : 30000, "getLastErrorModes" : {
}, "getLastErrorDefaults" : { "w" : 1, "wtimeout" : }, "replicaSetId" : ObjectId("61b86af0a21015e69623e18d") }}
将node3的节点的权重改为10
var cfg = rs.conf()cfg.members[3].priority = 10重新加载配置，选主
rs.reconfig(cfg)通常1分钟内完成切换。
PS：也可以通过rs.stepDown()
PRIMARY> rs.stepDown() //rs.stepDown(30) 单位：S
2. 剔除节点
剔除的节点为SECONDARY或ARBITER，可以执行通过rs.remove() 命令剔除对应节点，如为PRIMARY节点，则先进行主从切换，再剔除。test12:PRIMARY> rs.remove("192.168.56.199:27018"){ "ok" : 1, "$clusterTime" : { "clusterTime" : Timestamp(1639683041, 1), "signature" : { "hash" : BinData(,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="), "keyId" : NumberLong() } }, "operationTime" : Timestamp(1639683041, 1)}相关文章