MongoDB 副本集主从切换方法

一、方法一rs.setpDown()

将Primary节点降级为Secondary节点

myapp:PRIMARY> rs.stepDown()

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。

也可手动指定时间

myapp:PRIMARY> rs.stepDown(30)

在执行完该命令后，原Secondary node3:27017升级为Primary。

二、方法二优先级设置

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。

操作如下:

点击(此处)折叠或打开

				 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) failed
				2017-12-22T15:19:56.597+0800 I NETWORK  reconnect 127.0.0.1:27017 (127.0.0.1) ok

				arps: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
				}

 

整理自：

https://www.cnblogs.com/ivictor/p/6804408.html

http://blog.chinaunix.net/uid-26446098-id-5781440.html