Mongo副本集搭建方式

三台服务器：
172.16.252.128
172.16.252.129
172.16.252.130

1、下载mongo 4.2
https://www.mongodb.com/try/download/community

[root@localhost ~]# wget https://fastdl.mongodb.org/linux/mongodb-linux-x86_64-rhel70-4.2.14.tgz
[root@localhost ~]# tar xvf mongodb-linux-x86_64-rhel70-4.2.14.tgz -C /usr/local/
[root@localhost ~]# mv /usr/local/mongodb-linux-x86_64-rhel70-4.2.14/ /usr/local/mongo

[root@localhost ~]# vi ~/.bash_profile
加入
PATH=$PATH:/usr/local/mongo/bin

[root@localhost ~]# source ~/.bash_profile

mongo副本集搭建：

创建目录

mkdir -p /data/mongodb/{data,log,security}

vi /etc/mongod.conf 粘贴下内容

storage:
  dbPath: /data/mongodb/data
  journal:
    enabled: true

systemLog:
  quiet: true
  destination: file
  logAppend: true
  path: /data/mongodb/log/mongod.log

processManagement:
   fork: true

net:
  port: 27017
  bindIp: 0.0.0.0

replication:
  replSetName: rs0

#security:
#  keyFile: /data/mongodb/security/mongodb-keyfile

operationProfiling:
  slowOpThresholdMs: 1000
  mode: slowOp

启动数据库

mongod --config /etc/mongod.conf

登录数据库
因为没有密码验证，所以可以直接登录，但副本集还未配置，show dbs命令会报异常。

[root@localhost data]# mongo


> show dbs
2021-05-19T10:54:22.315+0800 E QUERY [js] uncaught exception: Error: listDatabases failed:{
"ok" : 0,
"errmsg" : "not master and slaveOk=false",
"code" : 13435,
"codeName" : "NotPrimaryNoSecondaryOk"
} :
_getErrorWithCode@src/mongo/shell/utils.js:25:13
Mongo.prototype.getDBs/<@src/mongo/shell/mongo.js:147:19
Mongo.prototype.getDBs@src/mongo/shell/mongo.js:99:12
shellHelper.show@src/mongo/shell/utils.js:906:13
shellHelper@src/mongo/shell/utils.js:790:15
@(shellhelp2):1:1
>

然后依次配置启动129，130两个服务器的mongo

登录128服务器mongo数据库，初始化副本集群

rsconf = {
  _id: "rs0",
  members: [
    {
     _id: 0,
     host: "172.16.252.18:27017"
    },
    {
     _id: 1,
     host: "172.16.252.18:27017"
    },
    {
     _id: 2,
     host: "172.16.252.18:27017"
    }
   ]
}

rs.initiate( rsconf )

进入任意一个其它节点，命令行显示为secondary

rs0:SECONDARY>

集群配置已经正常。

配置身份验证，

连接primary节点数据库

use admin
db.createUser({
  user: "root",
  pwd: "root",
  roles: [
    {role: "userAdminAnyDatabase", db:"admin"},
    {role: "readWriteAnyDatabase", db: "admin"},
    {role:"clusterAdmin", db:"admin"}
  ]
})

操作系统生成key，并拷贝到其它服务器

[root@localhost ~]# openssl rand -base64 512 > /data/mongodb/security/mongodb-keyfile
[root@localhost ~]# chmod 400 /data/mongodb/security/mongodb-keyfile

拷贝到129、130服务器。
[root@localhost ~]# scp /data/mongodb/security/mongodb-keyfile root@172.16.252.129:/data/mongodb/security/mongodb-keyfile
[root@localhost ~]# scp /data/mongodb/security/mongodb-keyfile root@172.16.252.130:/data/mongodb/security/mongodb-keyfile

杀进程

pkill mongod

vi /etc/mongod.conf ---修改配置文件，取消两行注释

security:
keyFile: /data/mongodb/security/mongodb-keyfile

启动数据库。

[root@localhost ~]# mongod --config /etc/mongod.conf
再次登录时需要验证
rs0:PRIMARY> use admin
switched to db admin
rs0:PRIMARY> db.auth("root","root")

参考文档：
https://wylu.me/posts/fd4a1d37/
https://docs.mongodb.com/manual/reference/configuration-options/