MongoDB副本集搭建

准备

MongoDB下载地址4.0.2版本

安装

• 解压：tar -zvxf mongodb-linux-x86_64-rhel70-4.0.2.tgz /opt/app/
• 重命名：为了容易区分集群，我们把文件重命名 mv mongodb-linux-x86_64-rhel70-4.0.2 ./mongodb-4.0.2-0
• 多集群：假设我们是3个节点的集群，复制该文件夹三份，如下：

[root@dmfw-testdk mongo]# pwd
/opt/app/mongo
[root@dmfw-testdk mongo]# ls
mongodb-4.0.2-0  mongodb-4.0.2-1  mongodb-4.0.2-2

• 创建配置文件 touch mongodb.conf ，并将以下内容写入（这文件也要三份，别copy太开心，记得改路径，如果在一台服务器，记得改端口，大兄弟）

dbpath=/opt/app/mongodb-linux-x86_64-rhel70-4.0.2-0/data
logpath=/opt/app/mongodb-linux-x86_64-rhel70-4.0.2-0/log/mongodb.log
fork=true
logappend=true
bind_ip=0.0.0.0
port=27017

replSet=aps-mongo

启动

• 进入到bin目录 cd /opt/app/mongo/mongodb-4.0.2-0/bin
• 执行 ./mongod -config ../mongodb.conf输出以下内容视为成功

2022-02-14T14:15:17.189+0800 I CONTROL  [main] Automatically disabling TLS 1.0, to force-enable TLS 1.0 specify --sslDisabledProtocols 'none'
about to fork child process, waiting until server is ready for connections.
forked process: 7198
child process started successfully, parent exiting

集群的三个节点都要依次启动

关闭

• 执行命令：./mongod --shutdown --dbpath ../data
• mongodb集群有自动切换主库功能，如果先关主库，主库就切换到其它上面去了，这里预防主库变更，从库关闭后再关闭主库

---

副本集

• 链接mongo ./mongo localhost:27017 (当然也可以选择工具来操作)

• 初始化

#配置节点信息
conf=
    {
    "_id" : "aps-mongo",
    "members" : [
        { "_id" : 0, "host" : "172.****:27017" },
        { "_id" : 1, "host" : "172.****:27018" },
        { "_id" : 2, "host" : "172.****:27019" }
        ]
    }
# 初始化节点
rs.initiate(conf)

• 查看配置

> rs.conf()
{
    "_id" : "aps-mongo",
    "version" : 1,
    "protocolVersion" : NumberLong(1),
    "writeConcernMajorityJournalDefault" : true,
    "members" : [
        {
            "_id" : 0,
            "host" : "172.****:27017",
            "arbiterOnly" : false,
            "buildIndexes" : true,
            "hidden" : false,
            "priority" : 1,
            "tags" : {
                
            },
            "slaveDelay" : NumberLong(0),
            "votes" : 1
        },
        {
            "_id" : 1,
            "host" : "172.****:27018",
            "arbiterOnly" : false,
            "buildIndexes" : true,
            "hidden" : false,
            "priority" : 1,
            "tags" : {
                
            },
            "slaveDelay" : NumberLong(0),
            "votes" : 1
        },
        {
            "_id" : 2,
            "host" : "172.****:27019",
            "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("620a0cc5d6479d18ad5e9e37")
    }
}
aps-mongo:PRIMARY> 

• 查看集群状态

rs.status()

{
    "set" : "aps-mongo",
    "date" : ISODate("2022-02-14T16:21:49.863+08:00"),
    "myState" : 1,
    "term" : 1,
    "syncingTo" : "",
    "syncSourceHost" : "",
    "syncSourceId" : -1,
    "heartbeatIntervalMillis" : 2000,
    "optimes" : {
        "lastCommittedOpTime" : {
            "ts" : Timestamp(1644826909, 1),
            "t" : 1
        },
        "readConcernMajorityOpTime" : {
            "ts" : Timestamp(1644826909, 1),
            "t" : 1
        },
        "appliedOpTime" : {
            "ts" : Timestamp(1644826909, 1),
            "t" : 1
        },
        "durableOpTime" : {
            "ts" : Timestamp(1644826909, 1),
            "t" : 1
        }
    },
    "lastStableCheckpointTimestamp" : Timestamp(1644826889, 1),
    "members" : [
        {
            "_id" : 0,
            "name" : "172.*.*.*:27017",
            "health" : 1,
            "state" : 1,
            "stateStr" : "PRIMARY",
            "uptime" : 4916,
            "optime" : {
                "ts" : Timestamp(1644826909, 1),
                "t" : 1
            },
            "optimeDate" : ISODate("2022-02-14T16:21:49.000+08:00"),
            "syncingTo" : "",
            "syncSourceHost" : "",
            "syncSourceId" : -1,
            "infoMessage" : "",
            "electionTime" : Timestamp(1644825808, 1),
            "electionDate" : ISODate("2022-02-14T16:03:28.000+08:00"),
            "configVersion" : 1,
            "self" : true,
            "lastHeartbeatMessage" : ""
        },
        {
            "_id" : 1,
            "name" : "172.*.*.*:27018",
            "health" : 1,
            "state" : 2,
            "stateStr" : "SECONDARY",
            "uptime" : 1112,
            "optime" : {
                "ts" : Timestamp(1644826899, 1),
                "t" : 1
            },
            "optimeDurable" : {
                "ts" : Timestamp(1644826899, 1),
                "t" : 1
            },
            "optimeDate" : ISODate("2022-02-14T16:21:39.000+08:00"),
            "optimeDurableDate" : ISODate("2022-02-14T16:21:39.000+08:00"),
            "lastHeartbeat" : ISODate("2022-02-14T16:21:48.719+08:00"),
            "lastHeartbeatRecv" : ISODate("2022-02-14T16:21:49.184+08:00"),
            "pingMs" : 0,
            "lastHeartbeatMessage" : "",
            "syncingTo" : "172.16.1.207:27017",
            "syncSourceHost" : "172.16.1.207:27017",
            "syncSourceId" : 0,
            "infoMessage" : "",
            "configVersion" : 1
        },
        {
            "_id" : 2,
            "name" : "172.*.*.*:27019",
            "health" : 1,
            "state" : 2,
            "stateStr" : "SECONDARY",
            "uptime" : 1112,
            "optime" : {
                "ts" : Timestamp(1644826899, 1),
                "t" : 1
            },
            "optimeDurable" : {
                "ts" : Timestamp(1644826899, 1),
                "t" : 1
            },
            "optimeDate" : ISODate("2022-02-14T16:21:39.000+08:00"),
            "optimeDurableDate" : ISODate("2022-02-14T16:21:39.000+08:00"),
            "lastHeartbeat" : ISODate("2022-02-14T16:21:48.719+08:00"),
            "lastHeartbeatRecv" : ISODate("2022-02-14T16:21:49.184+08:00"),
            "pingMs" : 0,
            "lastHeartbeatMessage" : "",
            "syncingTo" : "172.16.1.207:27017",
            "syncSourceHost" : "172.16.1.207:27017",
            "syncSourceId" : 0,
            "infoMessage" : "",
            "configVersion" : 1
        }
    ],
    "ok" : 1,
    "operationTime" : Timestamp(1644826909, 1),
    "$clusterTime" : {
        "clusterTime" : Timestamp(1644826909, 1),
        "signature" : {
            "hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
            "keyId" : 0
        }
    }
}

• 权限

// 生成base64内容的文件，然后在mongo.conf里面配置这个文件路径，重启就可以了
[root@dmfw-testdk bin]# openssl rand -base64 666 > /opt/app/mongo/keyfile
[root@dmfw-testdk bin]# cd /opt/app/mongo/
[root@dmfw-testdk mongo]# ls
keyfile  mongodb-4.0.2-0  mongodb-4.0.2-1  mongodb-4.0.2-2

//给当前用户设置读写权限，这儿科普下linux知识点：看接下去的第五行；rwx可以用数字421代替，600说明是当前用户的读写权限；就是这样，所以别一来就瞎鸡儿给 chmod 777 ;这儿还可以科普下chown和chmod的区别，前者是我把群主给你，你就拥有权限了，后者是我把你设置为管理员，差不多就是这个意思
[root@dmfw-testdk mongo]# chmod 600 ./keyfile  
[root@dmfw-testdk mongo]# ll
total 4
-rw------- 1 root root 902 Feb 15 09:28 keyfile
//看这排字母 drwxr-xr-x  d 是document的缩写，标识这个是个文件夹，后面有9位，前三代表当前用户，中三代表组，后三代表其他；
drwxr-xr-x 5 root root 187 Feb 14 14:51 mongodb-4.0.2-0
drwxr-xr-x 5 root root 187 Feb 14 15:00 mongodb-4.0.2-1
drwxr-xr-x 5 root root 187 Feb 14 15:01 mongodb-4.0.2-2

• 客户端工具下载地址：https://nosqlbooster.com/downloads

mongodb的副本集和redis的哨兵模式类似，都是基于故障自动切换的主从模式。主提供写读，从提供读。从各个节点的日志来看，会有2秒一次的心跳检测，发现宕机后，会进行选举，切换主节点，后面单独写一篇文章分析