mongodb副本集(PSA)添加新节点

OS:Centos 7
mongodb:4.4.22

当前环境
192.168.107 primary
192.168.104 secondary
192.168.106 arbiter

新添加机器ip为:192.168.1.108 作为从库加入(secondary)

1.解压
[root@test soft]# tar -xvf mongodb-linux-x86_64-rhel70-4.4.22.tgz
[root@test soft]# mv mongodb-linux-x86_64-rhel70-4.4.22 /usr/local/services/mongodb

 

2.创建相应目录
[root@test services]# mkdir -p /usr/local/services
[root@test services]# mkdir -p /home/middle/mongodb/data
[root@test services]# mkdir -p /home/middle/mongodb/log
[root@test services]# mkdir -p /home/middle/mongodb/key
[root@test services]# mkdir -p /home/middle/mongodb/conf
[root@test services]# mkdir -p /home/middle/mongodb/run

 

3.拷贝当前的密钥文件到新机器
scp keyfile root@192.168.1.108:/home/middle/mongodb/key/

 

4.创建配置文件 mongo.cnf
vi /home/middle/mongodb/conf/mongo.cnf

port=29001
fork=true
dbpath=/home/middle/mongodb/data
logpath=/home/middle/mongodb/log/mongodb.log
pidfilepath=/home/middle/mongodb/run/29001.pid
logappend=true
shardsvr=true
replSet=myrepl
bind_ip=192.168.1.108,127.0.0.1
oplogSize=16384
logRotate=reopen
keyFile=/home/middle/mongodb/key/keyfile
auth=true

 

5.启动
/usr/local/services/mongodb/bin/mongod -f /home/middle/mongodb/conf/mongo.cnf

 

6.登录主库(192.168.1.107)添加新节点
我们在副本集扩容的情况下,新加入节点一般设置priority和votes都为0,
即不会选为主(priority默认1,也没有投票特性votes默认1，有投票权)
待新节点数据同步完成后再进行修改
[root@localhost ~]# /usr/local/services/mongodb/bin/mongo localhost:29001
myrepl:PRIMARY> use admin
myrepl:PRIMARY> db.auth("test","test123");
myrepl:PRIMARY> rs.add({ host: "192.168.1.108:29001", priority: 0, votes: 0 })

这个时候查看集群的状态,新加入的节点状态为STARTUP2,正在初始化同步数据,副本集数据量大的情况下,初始化需要些时间.
等新节点初始化完成后,状态会修改为SECONDARY

 

7.修改priority和votes属性
myrepl:PRIMARY>cfg = rs.conf()
myrepl:PRIMARY>cfg.members[3].priority = 1
myrepl:PRIMARY>cfg.members[3].votes = 1
myrepl:PRIMARY>rs.reconfig(cfg)

好像当前环境至少存在一个从节点以上才能这样执行.

 

8.查看集群配置

myrepl:PRIMARY> rs.conf()
{
        "_id" : "myrepl",
        "version" : 23827,
        "protocolVersion" : NumberLong(1),
        "writeConcernMajorityJournalDefault" : true,
        "members" : [
                {
                        "_id" : 0,
                        "host" : "192.168.1.104:29001",
                        "arbiterOnly" : false,
                        "buildIndexes" : true,
                        "hidden" : false,
                        "priority" : 1,
                        "tags" : {

                        },
                        "slaveDelay" : NumberLong(0),
                        "votes" : 1
                },
                {
                        "_id" : 3,
                        "host" : "192.168.1.106:29001",
                        "arbiterOnly" : true,
                        "buildIndexes" : true,
                        "hidden" : false,
                        "priority" : 0,
                        "tags" : {

                        },
                        "slaveDelay" : NumberLong(0),
                        "votes" : 1
                },
                {
                        "_id" : 4,
                        "host" : "192.168.1.107:29001",
                        "arbiterOnly" : false,
                        "buildIndexes" : true,
                        "hidden" : false,
                        "priority" : 1,
                        "tags" : {

                        },
                        "slaveDelay" : NumberLong(0),
                        "votes" : 1
                },
                {
                        "_id" : 5,
                        "host" : "192.168.1.108:29001",
                        "arbiterOnly" : false,
                        "buildIndexes" : true,
                        "hidden" : false,
                        "priority" : 1,
                        "tags" : {

                        },
                        "slaveDelay" : NumberLong(0),
                        "votes" : 1
                }
        ],
        "settings" : {
                "chainingAllowed" : true,
                "heartbeatIntervalMillis" : 2000,
                "heartbeatTimeoutSecs" : 10,
                "electionTimeoutMillis" : 10000,
                "catchUpTimeoutMillis" : -1,
                "catchUpTakeoverDelayMillis" : 30000,
                "getLastErrorModes" : {

                },
                "getLastErrorDefaults" : {
                        "w" : 1,
                        "wtimeout" : 0
                },
                "replicaSetId" : ObjectId("64b0a3f881b811c4931d4d4c")
        }
}