replica set多服务器主从，添加，删除节点，肯定会经常遇到的。下面详细说明一下，添加，删除节点的2种方法。
一，利用rs.reconfig，来添加，删除节点
1，添加节点
代码如下repmore:PRIMARY> config = {_id:"repmore",members:[{_id:0,host:'127.0.0.1:27017',priority :2},{_id:1,host:'127.0.0.1:27018',priority:1}]}; //添加节点
repmore:PRIMARY> rs.reconfig(config); //使配置生效
repmore:PRIMARY> rs.status(); //查看节点状态
节点添加成功。
注意：新增节点的replSet要和其他节点要一样
2,删除节点(删除节点前最好是先关闭需要删除的节点，之后通过命令 rs.remove 来删除)
代码如下repmore:PRIMARY> config = {_id:"repmore",members:[{_id:0,host:'127.0.0.1:27017',priority :2}]}; //删除节点
repmore:PRIMARY> rs.reconfig(config); //使配置生效
repmore:PRIMARY> rs.status(); //查看节点状态
二，利用rs.add和rs.remove来添加删除节点
代码如下repmore:PRIMARY> rs.add("127.0.0.1:27018"); //添加节点
repmore:PRIMARY> rs.remove("127.0.0.1:27018"); //删除节
注意：利用rs.add和rs.remove是不用rs.reconfig来使用配置生效的。
最后对于删除节点我这里再附一个标准流程给各位
相应的节点，操作如下：
代码如下--1 查看当前 Replica Set 配置
[mongo@redhatB mongodb]$ mongo 127.0.0.1:27018
MongoDB shell version: 2.2.1
connecting to: 127.0.0.1:27018/test
rs0:PRIMARY> rs.conf();
{
"_id" : "rs0",
"version" : 4,
"members" : [
{
"_id" : 0,
"host" : "redhatB.example.com:27018"
},
{
"_id" : 1,
"host" : "redhatB.example.com:27019"
},
{
"_id" : 2,
"host" : "redhatB.example.com:27020"
},
{
"_id" : 3,
"host" : "redhatB.example.com:27021"
}
]
}
备注：计划删除节点 "_id" : 3。
--2 关闭 27021 节点服务
[mongo@redhatB data04]$ ps -ef | grep 27021
mongo 11733 1 0 21:03 ? 00:00:15 mongod -f /pgdata_xc/mongodb/data04/mongodb_27021.conf
mongo 14422 2953 0 21:53 pts/0 00:00:00 mongo 127.0.0.1:27021
mongo 14490 4027 0 21:54 pts/1 00:00:00 grep 27021
[mongo@redhatB data04]$ kill 11733
--3 查看 replica set 状态
rs0:PRIMARY> rs.status();
{
"set" : "rs0",
"date" : ISODate("2012-11-22T13:57:15Z"),
"myState" : 1,
"members" : [
{
"_id" : 0,
"name" : "redhatB.example.com:27018",
"health" : 1,
"state" : 1,
"stateStr" : "PRIMARY",
"uptime" : 21279,
"optime" : Timestamp(1353589624000, 1),
"optimeDate" : ISODate("2012-11-22T13:07:04Z"),
"self" : true
},
{
"_id" : 1,
"name" : "redhatB.example.com:27019",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 18908,
"optime" : Timestamp(1353589624000, 1),
"optimeDate" : ISODate("2012-11-22T13:07:04Z"),
"lastHeartbeat" : ISODate("2012-11-22T13:57:13Z"),
"pingMs" : 0
},
{
"_id" : 2,
"name" : "redhatB.example.com:27020",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 18900,
"optime" : Timestamp(1353589624000, 1),
"optimeDate" : ISODate("2012-11-22T13:07:04Z"),
"lastHeartbeat" : ISODate("2012-11-22T13:57:14Z"),
"pingMs" : 0
},
{
"_id" : 3,
"name" : "redhatB.example.com:27021",
"health" : 0,
"state" : 8,
"stateStr" : "(not reachable/healthy)",
"uptime" : 0,
"optime" : Timestamp(1353589624000, 1),
"optimeDate" : ISODate("2012-11-22T13:07:04Z"),
"lastHeartbeat" : ISODate("2012-11-22T13:55:20Z"),
"pingMs" : 0,
"errmsg" : "socket exception [CONNECT_ERROR] for redhatB.example.com:27021"
}
],
"ok" : 1
}
备注：最后一个节点 stateStr 状态为 “not reachable/healthy”。
--4 删除节点
rs0:PRIMARY> rs.remove("redhatB.example.com:27021");
Thu Nov 22 21:58:45 DBClientCursor::init call() failed
Thu Nov 22 21:58:45 query failed : admin.$cmd { replSetReconfig: { _id: "rs0", version: 5, members: [ { _id: 0, host: "redhatB.example.com:27018" }, { _id: 1, host: "redhatB.example.com:27019" }, { _id: 2, host: "redhatB.example.com:27020" } ] } } to: 127.0.0.1:27018
Thu Nov 22 21:58:45 Error: error doing query: failed src/mongo/shell/collection.js:155
Thu Nov 22 21:58:45 trying reconnect to 127.0.0.1:27018
Thu Nov 22 21:58:45 reconnect 127.0.0.1:27018 ok
rs0:SECONDARY>
rs0:PRIMARY>
--5 再次查看 replica set 配置
rs0:PRIMARY> rs.conf();
{
"_id" : "rs0",
"version" : 5,
"members" : [
{
"_id" : 0,
"host" : "redhatB.example.com:27018"
},
{
"_id" : 1,
"host" : "redhatB.example.com:27019"
},
{
"_id" : 2,
"host" : "redhatB.example.com:27020"
}
]
}
备注：节点 "redhatB.example.com:27021" 已删除。
--6 删除旧结点数据目录
代码如下[mongo@redhatB mongodb]$ rm -rf /mongodb/data04
