docker-compose搭建mongoDB副本集（1主+1副+1仲裁）

一、基本概念

1、副本集：一个副本集就是一组MongoDB实例组成的集群，由一个主（Primary）服务器和多个备份（Secondary）服务器构成

2、主节点（master）：主节点接收所有写入操作。主节点将对其数据集所做的所有更改记录到其 oplog。

3、副节点（secondary）：复制主节点的 oplog 并将操作应用到其数据集，如果主节点不可用，一个合格的副节点将被选为新的主节点。

4、仲裁节点（arbiter）：负载选举，当主节点不可用，它将从副节点中选一个作为主节点。

二、部署副本集

1、下载monodb镜像，我这里版本为：3.2.11

docker pull registry.cn-hangzhou.aliyuncs.com/boshen-ns/mongodb:3.2.11
docker tag docker pull registry.cn-hangzhou.aliyuncs.com/boshen-ns/mongodb:3.2.11 mongodb:3.2.11

2、创建三个mongodb的数据目录：

mkdir -p /home/mongodb-cluster/data/master
mkdir -p /home/mongodb-cluster/data/secondary
mkdir -p /home/mongodb-cluster/data/arbiter

3、编写docker-compose.yml

version: '2.1'
services:
  master:
    image: mongodb:3.2.
    container_name: master
    restart: always
    ports:
      - :
    volumes:
      - ./data/master:/data/db
    command: mongod --dbpath /data/db --replSet testSet --oplogSize
  secondary:
    image: mongodb:3.2.
    container_name: secondary
    restart: always
    ports:
      - :
    volumes:
      - ./data/secondary:/data/db
    command: mongod --dbpath /data/db --replSet testSet --oplogSize
  arbiter:
    image: mongodb:3.2.
    container_name: arbiter
    restart: always
    ports:
      - :
    volumes:
      - ./data/arbiter:/data/db
    command: mongod --replSet testSet --smallfiles --oplogSize 

4、启动

docker-compse up -d

5、配置副本集

1）进入容器内部：

docker exec -it master mongo

2）在mongo shell里面执行：rs.initiate()

3）继续执行：rs.add('172.16.1.11:27018')  表示将secondary添加进副本集

4）继续执行：rs.add('172.16.1.11:27019',true)   其中true表示这个节点是仲裁节点

5）查看配置

testSet:PRIMARY> rs.conf()
{
    "_id" : "testSet",
    "version" : 77284,
    "protocolVersion" : NumberLong(1),
    "members" : [
        {
            "_id" : 0,
            "host" : "172.16.1.11:27017",
            "arbiterOnly" : false,
            "buildIndexes" : true,
            "hidden" : false,
            "priority" : 1,
            "tags" : {

            },
            "slaveDelay" : NumberLong(0),
            "votes" : 1
        },
        {
            "_id" : 1,
            "host" : "172.16.1.11:27018",
            "arbiterOnly" : false,
            "buildIndexes" : true,
            "hidden" : false,
            "priority" : 1,
            "tags" : {

            },
            "slaveDelay" : NumberLong(0),
            "votes" : 1
        },
        {
            "_id" : 2,
            "host" : "172.16.1.11:27019",
            "arbiterOnly" : true,
            "buildIndexes" : true,
            "hidden" : false,
            "priority" : 1,
            "tags" : {

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

        },
        "getLastErrorDefaults" : {
            "w" : 1,
            "wtimeout" : 0
        },
        "replicaSetId" : ObjectId("5c6fb85fb21aeac107319862")
    }
}

6）查看状态

testSet:PRIMARY> rs.status()
{
    "set" : "testSet",
    "date" : ISODate("2019-02-26T02:12:48.124Z"),
    "myState" : 1,
    "term" : NumberLong(2),
    "heartbeatIntervalMillis" : NumberLong(2000),
    "members" : [
        {
            "_id" : 0,
            "name" : "172.16.1.11:27017",
            "health" : 1,
            "state" : 2,
            "stateStr" : "SECONDARY",
            "uptime" : 268,
            "optime" : {
                "ts" : Timestamp(1551147003, 4),
                "t" : NumberLong(2)
            },
            "optimeDate" : ISODate("2019-02-26T02:10:03Z"),
            "lastHeartbeat" : ISODate("2019-02-26T02:12:46.189Z"),
            "lastHeartbeatRecv" : ISODate("2019-02-26T02:12:46.188Z"),
            "pingMs" : NumberLong(0),
            "syncingTo" : "172.16.1.11:27018",
            "configVersion" : 77284
        },
        {
            "_id" : 1,
            "name" : "172.16.1.11:27018",
            "health" : 1,
            "state" : 1,
            "stateStr" : "PRIMARY",
            "uptime" : 938,
            "optime" : {
                "ts" : Timestamp(1551147003, 4),
                "t" : NumberLong(2)
            },
            "optimeDate" : ISODate("2019-02-26T02:10:03Z"),
            "electionTime" : Timestamp(1551146242, 1),
            "electionDate" : ISODate("2019-02-26T01:57:22Z"),
            "configVersion" : 77284,
            "self" : true
        },
        {
            "_id" : 2,
            "name" : "172.16.1.11:27019",
            "health" : 1,
            "state" : 7,
            "stateStr" : "ARBITER",
            "uptime" : 270,
            "lastHeartbeat" : ISODate("2019-02-26T02:12:46.189Z"),
            "lastHeartbeatRecv" : ISODate("2019-02-26T02:12:48.118Z"),
            "pingMs" : NumberLong(0),
            "configVersion" : 77284
        }
    ],
    "ok" : 1
}

如果想要修改副本集的配置，可以采用以下方法：

conf=rs.conf()
conf.members[0].host="172.16.1.11:27017"
rs.reconfig(conf,{"force":true})

三、验证mongdb可用性：

由上测试可知：副节点只能读，不能写

二、windows客户端连接mongodb

1、登录mongo shell，创建一个admin用户

testSet:PRIMARY> db.createUser({user:"admin",pwd:"admin",roles:[{"role":"userAdminAnyDatabase","db":"admin"},{"role":"readWrite","db":"testdb"}]})
Successfully added user: {
    "user" : "admin",
    "roles" : [
        {
            "role" : "userAdminAnyDatabase",
            "db" : "admin"
        },
        {
            "role" : "readWrite",
            "db" : "testdb"
        }
    ]
}

2、安装 robomongo-1.0.0-windows-x86_64-89f24ea.exe

3、填写连接信息