Mongodb副本集-切换主从节点

思路:1.为了保证数据的一致性，必须先关闭应用的写服务。2.提升要升级为Primary节点的Secondary节点的优先级。arps:PRIMARY> config=rs.conf()                //查看当前配置，存入config变量中。arps:PRIMARY> config.members[2].priority = 3  //修改config变量，第三组成员的优先级为3.arps:PRIMARY> rs.reconfig(config)             //配置生效............2017-12-22T15:19:56.596+0800 I NETWORK trying reconnect to 127.0.0.1:27017 (127.0.0.1) failed2017-12-22T15:19:56.597+0800 I NETWORK reconnect 127.0.0.1:27017 (127.0.0.1) okarps:SECONDARY> rs.conf()                    //查看当前配置{"_id" : "arps","version" : 4,"members" : [{"_id" : 0,"host" : "172.17.4.37:27017","arbiterOnly" : false,"buildIndexes" : true,"hidden" : false,"priority" : 1,"tags" : {},"slaveDelay" : 0,"votes" : 1},{"_id" : 1,"host" : "172.17.4.38:27017","arbiterOnly" : false,"buildIndexes" : true,"hidden" : false,"priority" : 1,"tags" : {},"slaveDelay" : 0,"votes" : 1},{"_id" : 2,"host" : "172.17.4.39:27017","arbiterOnly" : false,"buildIndexes" : true,"hidden" : false,"priority" : 3,             //优先级变为3"tags" : {},"slaveDelay" : 0,"votes" : 1}],"settings" : {"chainingAllowed" : true,"heartbeatTimeoutSecs" : 10,"getLastErrorModes" : {},"getLastErrorDefaults" : {"w" : 1,"wtimeout" : 0}}}arps:SECONDARY> rs.status(){"set" : "arps","date" : ISODate("2017-12-22T07:25:04.641Z"),"myState" : 2,"syncingTo" : "172.17.4.39:27017","members" : [{"_id" : 0,"name" : "172.17.4.37:27017","health" : 1,"state" : 2,"stateStr" : "SECONDARY","uptime" : 7597536,"optime" : Timestamp(1513927481, 3),"optimeDate" : ISODate("2017-12-22T07:24:41Z"),"syncingTo" : "172.17.4.39:27017","configVersion" : 4,"self" : true},{"_id" : 1,"name" : "172.17.4.38:27017","health" : 1,"state" : 2,"stateStr" : "SECONDARY","uptime" : 7597426,"optime" : Timestamp(1513927481, 3),"optimeDate" : ISODate("2017-12-22T07:24:41Z"),"lastHeartbeat" : ISODate("2017-12-22T07:25:02.961Z"),"lastHeartbeatRecv" : ISODate("2017-12-22T07:25:04.091Z"),"pingMs" : 0,"syncingTo" : "172.17.4.39:27017","configVersion" : 4},{"_id" : 2,"name" : "172.17.4.39:27017","health" : 1,"state" : 1,"stateStr" : "PRIMARY",    //最后一个节点升级为PRIMARY"uptime" : 3202,"optime" : Timestamp(1513927481, 3),"optimeDate" : ISODate("2017-12-22T07:24:41Z"),"lastHeartbeat" : ISODate("2017-12-22T07:25:02.951Z"),"lastHeartbeatRecv" : ISODate("2017-12-22T07:25:04.344Z"),"pingMs" : 0,"electionTime" : Timestamp(1513927190, 2),"electionDate" : ISODate("2017-12-22T07:19:50Z"),"configVersion" : 4}],"ok" : 1}