《云计算》-MongoDB服务器：MongoDB副本集配置

1 案例1：配置MongoDB副本集
1.1 问题

具体要求：
准备3台mongodb服务器
配置副本集服务
验证副本集配置

1.2 方案

准备三台虚拟机，配置mongodb副本集，ip分别为192.158.4.51， 192.168.4.52，192.168.4.53其中一个是主节点，负责处理客户端请求，其余的都是从节点，负责复制主节点上的数据，实现存储数据副本，提高了数据的可用性，具体分配如表-1所示：

表-1
1.3 步骤

实现此案例需要按照如下步骤进行。

步骤一：创建mongodb副本集

1）三台主机安装mongodb（以4.51为例）

[root@mongodb51 ~]# cd mongodb/
[root@mongodb51 mongodb]#  mkdir  /usr/local/mongodb
[root@mongodb51 mongodb]# cd /usr/local/mongodb
[root@mongodb51 mongodb]# cp -r \ 
 /root/mongodb/mongodb-linux-x86_64-rhel70-3.6.3/bin/  .
[root@mongodb51 mongodb]# ls
bin
[root@mongodb51 mongodb]# mkdir etc
[root@mongodb51 mongodb]# mkdir log
[root@mongodb51 mongodb]# mkdir -p data/db
[root@mongodb51 mongodb]# vim etc/mongodb.conf
dbpath=/usr/local/mongodb/data/db/
logpath=/usr/local/mongodb/log/mongodb.log
logappend=true 
fork=true
bind_ip=192.168.4.51
port=27077
replSet=rs1        
//加入到副本集，rs1名字随便起，想知道谁和我在一个副本集里，三台机器的名字一样,都写rs1

2）设置PATH变量

[root@mongodb51 mongodb]# vim /etc/profile
export PATH=/usr/local/mongodb/bin:$PATH
[root@mongodb51 mongodb]# source  /etc/profile

3）由于启动和停止服务名字太长，可以起一个别名

给停止服务起一个别名

[root@mongodb51 mongodb]# alias cmdb='mongod  --dbpath=/usr/local/mongodb/data/db/  --shutdown'

给启动服务起一个别名

[root@mongodb51 mongodb]# alias smdb='mongod -f /usr/local/mongodb/etc/mongodb.conf'

4）启动服务并连接

[root@mongodb51 ~]# smdb
about to fork child process, waiting until server is ready for connections.
forked process: 5656
child process started successfully, parent exiting
[root@mongodb51 ~]# mongo --host 192.168.4.51 --port 27077
MongoDB shell version v3.6.3
connecting to: mongodb://192.168.4.51:27077/
MongoDB server version: 3.6.3
...
> 

5）配置集群信息，任意一台都可以，在这里在51上面操作

> rs1_config = {        //rs1_config随便起变量名,要记住
 _id:"rs1",         //必须为rs1这个，三台主机集群名，配置文件里面写的是这个
 members:[
 {_id:0,host:"192.168.4.51:27077"},        //_id值随意，host值固定
 {_id:1,host:"192.168.4.52:27078"},
 {_id:2,host:"192.168.4.53:27079"}
 ]
 };        //回车，出现下面情况为成功
{
    "_id" : "rs1",
    "members" : [
        {
            "_id" : 0,
            "host" : "192.168.4.51:27077"
        },
        {
            "_id" : 1,
            "host" : "192.168.4.52:27078"
        },
        {
            "_id" : 2,
            "host" : "192.168.4.53:27079"
        }
    ]
}
>

6）初始化Replica Sets环境

> rs.initiate(rs1_config)
{
    "ok" : 1,
    "operationTime" : Timestamp(1538187475, 1),
    "$clusterTime" : {
        "clusterTime" : Timestamp(1538187475, 1),
        "signature" : {
            "hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
            "keyId" : NumberLong(0)
        }
    }
}
rs1:SECONDARY> 
rs1:PRIMARY>            //提示PRIMARY，51为主

7）在52和53上面查看

[root@mongodb52 ~]# mongo --host 192.168.4.52 --port 27078
MongoDB shell version v3.6.3
connecting to: mongodb://192.168.4.52:27078/
MongoDB server version: 3.6.3
...
... 
rs1:SECONDARY>         //提示SECONDARY，52为从
rs1:SECONDARY> 
rs1:SECONDARY>
[root@192 ~]# mongo --host 192.168.4.53 --port 27079
MongoDB shell version v3.6.3
connecting to: mongodb://192.168.4.53:27079/
MongoDB server version: 3.6.3
...
... 
rs1:SECONDARY>     //提示SECONDARY，53为从
rs1:SECONDARY>

注意：如果初始化错误，重启服务登陆之后重新设置变量，之后再重新初始化

8）查看状态信息

rs1:PRIMARY>  rs.status()
...
    "members" : [
        {
            "_id" : 0,
            "name" : "192.168.4.51:27077",
            "health" : 1,
            "state" : 1,
            "stateStr" : "PRIMARY",
            "uptime" : 2295,
            ...
...
        },
        {
            "_id" : 1,
            "name" : "192.168.4.52:27078",
            "health" : 1,
            "state" : 2,
            "stateStr" : "SECONDARY",
            "uptime" : 384,
            ...
          ...
        },
        {
            "_id" : 2,
            "name" : "192.168.4.53:27079",
            "health" : 1,
            "state" : 2,
            "stateStr" : "SECONDARY",
...
...

9）查看是否是master库

rs1:PRIMARY>  rs .isMaster( )
{
    "hosts" : [
        "192.168.4.51:27077",
        "192.168.4.52:27078",
        "192.168.4.53:27079"
    ],
    "setName" : "rs1",
    "setVersion" : 1,
    "ismaster" : true,        //主库
    "secondary" : false,
    "primary" : "192.168.4.51:27077",
    "me" : "192.168.4.51:27077",
...
...

10）验证副本集，同步数据验证（51上面写数据）

rs1:PRIMARY> use gamedb2
switched to db gamedb2
rs1:PRIMARY> db.a.save({name:"yaya",age:75,em:"[email protected]"})
WriteResult({ "nInserted" : 1 })

52上面查看

[root@mongodb52 ~]# mongo --host 192.168.4.52 --port 27078
rs1:SECONDARY> db.getMongo().setSlaveOk()
rs1:SECONDARY> show dbs        //有gamedb2库
admin    0.000GB
config   0.000GB
ddsdb    0.000GB
gamedb2  0.000GB
local    0.000GB
test     0.000GB

步骤三：切换主库验证

1）自动切换主库验证

关闭51

[root@mongodb51 ~]# cmdb        //之前设置的别名
killing process with pid: 5656

查看52和53

[root@mongodb52 ~]# mongo --host 192.168.4.52 --port 27078
MongoDB shell version v3.6.3
connecting to: mongodb://192.168.4.52:27078/
MongoDB server version: 3.6.3
...
... 
rs1:PRIMARY>         //52为主
rs1:PRIMARY>
[root@mongodb53 ~]# mongo --host 192.168.4.53 --port 27079
MongoDB shell version v3.6.3
connecting to: mongodb://192.168.4.53:27079/
MongoDB server version: 3.6.3
...
... 
rs1:SECONDARY>        //53为从

启动51，启动后不会再变为主，会成为52的从

[root@mongodb51 ~]# smdb
about to fork child process, waiting until server is ready for connections.
forked process: 6598
child process started successfully, parent exiting
rs1:SECONDARY> rs.isMaster()
{
    "hosts" : [
        "192.168.4.51:27077",
        "192.168.4.52:27078",
        "192.168.4.53:27079"
    ],
    "setName" : "rs1",
    "setVersion" : 1,
    "ismaster" : false,
    "secondary" : true,
    "primary" : "192.168.4.52:27078",
    "me" : "192.168.4.51:27077",
...