MongoDB Replica-set 设置
本文用三个MongoDB server来架设replica-set。
首先分别准备三个UBuntu vm, 里面安装了MongoDB instance.
然后每个vm的/etc/hosts里面都包含了另外两个vm的ip和主机名。
这样确保每个vm都能通过主机名连接到其他两个vm.
我的vm分别是：vm1, vm3, vm4. IP分别是192.168.1.51, 192.168.1.52和192.168.1.53
依次登录所有的vm，然后编辑/etc/mongodb.conf文件，取消注释，并设置replSet
replSet = rs1 // 必须设置为一个名字，千万别不同添加
fork=true重新启动mongodb
service mongodb restart运行下面的命令：
ssh到vm3，登录到mongodb, 然后执行rs.initiate创建一个replicaset，并用config检查配置。
> rs.initiate()
{
"info2" : "no configuration explicitly specified -- making one",
"me" : "vm3:27017",
"info" : "Config now saved locally. Should come online in about a minute.",
"ok" : 1
}
> rs.config()
{
"_id" : "rs1",
"version" : 1,
"members" : [
{
"_id" : 0,
"host" : "vm3:27017"
}
]
}
注意，3个vm中只能选中一个运行rs.initiate命令，如果在其他的vm中不小心也运行了。需要用下面的方法清除之：
use local
db.dropDatabase()
exit
service mongodb restart然后在vm3的mongodb上继续执行rs.add命令：
root@vm3:~# mongo
MongoDB shell version: 2.4.3
connecting to: test
rs1:PRIMARY> rs.add("vm1")
{
"errmsg" : "exception: set name does not match the set name host vm1:27017 expects",
"code" : 13145,
"ok" : 0
}
rs1:PRIMARY> rs.add("vm4")
{
"errmsg" : "exception: set name does not match the set name host vm4:27017 expects",
"code" : 13145,
"ok" : 0
}把三个vm都重新启动，再试！
root@vm3:~# mongo
MongoDB shell version: 2.4.3
connecting to: test
rs1:PRIMARY> rs.add("vm4")
{ "ok" : 1 }
rs1:PRIMARY> rs.add("vm1")
{ "ok" : 1 }
成功了。不容易啊！再看一下配置：
rs1:PRIMARY> rs.config()
{
"_id" : "rs1",
"version" : 3,
"members" : [
{
"_id" : 0,
"host" : "vm3:27017"
},
{
"_id" : 1,
"host" : "vm4:27017"
},
{
"_id" : 2,
"host" : "vm1:27017"
}
]
}
来看看状态：
s1:PRIMARY> rs.status()
{
"set" : "rs1",
"date" : ISODate("2013-05-04T12:36:28Z"),
"myState" : 1,
"members" : [
{
"_id" : 0,
"name" : "vm3:27017",
"health" : 1,
"state" : 1,
"stateStr" : "PRIMARY",
"uptime" : 380,
"optime" : {
"t" : 1367670744,
"i" : 1
},
"optimeDate" : ISODate("2013-05-04T12:32:24Z"),
"self" : true
},
{
"_id" : 1,
"name" : "vm4:27017",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 248,
"optime" : {
"t" : 1367670744,
"i" : 1
},
"optimeDate" : ISODate("2013-05-04T12:32:24Z"),
"lastHeartbeat" : ISODate("2013-05-04T12:36:28Z"),
"lastHeartbeatRecv" : ISODate("1970-01-01T00:00:00Z"),
"pingMs" : 0,
"syncingTo" : "vm3:27017"
},
{
"_id" : 2,
"name" : "vm1:27017",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 244,
"optime" : {
"t" : 1367670744,
"i" : 1
},
"optimeDate" : ISODate("2013-05-04T12:32:24Z"),
"lastHeartbeat" : ISODate("2013-05-04T12:36:26Z"),
"lastHeartbeatRecv" : ISODate("2013-05-04T12:36:28Z"),
"pingMs" : 1,
"syncingTo" : "vm3:27017"
}
],
"ok" : 1
}
vm3已经被选举为primary了。