mongodb
主從模式就是一個 單副本的應用;沒有很好的擴展性和容錯性;
副本集的多個副本保證了容錯性;
主服務器負責整個副本集的讀寫,副本集定時同步數據;主節點掛掉;副本集會自動選舉一個主的服務器;
1,安裝配置;
主節點:
172.16.0.191
從點節點:
172.16.0.192
172.16.0.193
# wget https://fastdl.mongodb.org/linux/mongodb-linux-x86_64-rhel62-3.2.10.tgz
# tar -xf mongodb-linux-x86_64-rhel62-3.2.10.tgz -C /opt
# mv mongodb-linux-x86_64-rhel62-3.2.10.tgz mongod
# mkdir /data/replset/db # 設置副本集文件目錄 db數據目錄
2,啓動三臺mongod;(防火牆開放 27017 port )
/opt/mongod/bin/mongod --fork --port 27017 --dbpath /data/db --logpath /opt/mongod/log/mongodb.log --replSet oneset
這邊用172.16.0.191 作爲主節點服務;
3,進入mongod 配置副本集;
# /opt/mongod/bin/mongo
# 使用admin 數據庫
> use admin
switched to db admin
#定義副本集配置變量,這裏的 _id:”oneset” 和上面命令參數“ –replSet oneset” 要保持一樣。(可以自定義)
> config = { _:"oneset", members:[ {_id:0,host:"172.16.0.191:27017"}, {_id:1,host:"172.16.0.192:27017"}, {_id:2,host:"172.16.0.193:27017"}] }
{
"_id" : "oneset",
"members" : [
{
"_id" : 0,
"host" : "172.16.15.191:27017"
},
{
"_id" : 1,
"host" : "172.16.15.192:27017"
},
{
"_id" : 2,
"host" : "172.16.15.19327017"
}
]
}
#初始化副本集配置
>rs.initiate(config);
4,查閱副本集
>rs.conf() 或者 >rs.status()
5,任意一個從節點連接查看副本集狀態:
[root@mongodb3 mongod]# bin/mongo 172.16.0.191:27017
repset:PRIMARY> rs.status()
{
"set" : "repset",
"date" : ISODate("2016-10-12T08:21:20.622Z"),
"myState" : 1,
"term" : NumberLong(1),
"heartbeatIntervalMillis" : NumberLong(2000),
"members" : [
{
"_id" : 0,
"name" : "172.16.0.191:27017",
"health" : 1,
"state" : 1,
"stateStr" : "PRIMARY",
"uptime" : 1534,
"optime" : {
"ts" : Timestamp(1476260204, 2),
"t" : NumberLong(1)
},
"optimeDate" : ISODate("2016-10-12T08:16:44Z"),
"electionTime" : Timestamp(1476259079, 1),
"electionDate" : ISODate("2016-10-12T07:57:59Z"),
"configVersion" : 1,
"self" : true
},
{
"_id" : 1,
"name" : "172.16.0.192:27017",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 1411,
"optime" : {
"ts" : Timestamp(1476260204, 2),
"t" : NumberLong(1)
},
"optimeDate" : ISODate("2016-10-12T08:16:44Z"),
"lastHeartbeat" : ISODate("2016-10-12T08:21:19.392Z"),
"lastHeartbeatRecv" : ISODate("2016-10-12T08:21:18.816Z"),
"pingMs" : NumberLong(0),
"syncingTo" : "172.16.0.191:27017",
"configVersion" : 1
},
{
"_id" : 2,
"name" : "172.16.0.193:27017",
"health" : 1,
"state" : 2,
"stateStr" : "SECONDARY",
"uptime" : 1411,
"optime" : {
"ts" : Timestamp(1476260204, 2),
"t" : NumberLong(1)
},
"optimeDate" : ISODate("2016-10-12T08:16:44Z"),
"lastHeartbeat" : ISODate("2016-10-12T08:21:19.390Z"),
"lastHeartbeatRecv" : ISODate("2016-10-12T08:21:18.941Z"),
"pingMs" : NumberLong(0),
"syncingTo" : "172.16.0.191:27017",
"configVersion" : 1
}
],
"ok" : 1
}
6, 主節點插入一條測試數據;
repset:PRIMARY> use abcd
switched to db abcd
repset:PRIMARY> db.abcddb.insert({"name":"字母"})
WriteResult({ "nInserted" : 1 })
7,從節點查看;
# /opt/mongod/bin/mongo 172.16.0.191:27017
再:
# /opt/mongod/bin/mongo
# mongodb默認是從主節點讀寫數據的,副本節點上不允許讀,需要設置副本節點可以讀。
repset:SECONDARY> db.getMongo().setSlaveOk();
repset:SECONDARY> use abcd;
switched to db abcd
repset:SECONDARY> db.abcddb.find();
{ "_id" : ObjectId("57fe09dd38d5a26b011dfe06"), "name" : "字母" }}
8,加添節點
添加節點,需要在主節點進行
PRIMARY>>rs.add(hostname:port)
9,刪減節點
刪減節點,需要在主節點進行
PRIMARY>rs.remove(hostname:port)