MongoDB开发之 集群搭建

原理

复制集 = 主从复制 + 自动切换

架构

一主两从

image.png

一主一从一裁判

image.png

集群搭建

mkdir ./primary ./secondary ./arbiter

mongod --replSet demo --dbpath ./primary --port 40000

mongod --replSet demo --dbpath ./secondary --port 40001

mongod --replSet demo --dbpath ./arbiter --port 40002

查询状态

mongo --port 40000

> use admin

> rs.status()
{
    "operationTime" : Timestamp(0, 0),
    "ok" : 0,
    "errmsg" : "no replset config has been received",
    "code" : 94,
    "codeName" : "NotYetInitialized",
    "$clusterTime" : {
        "clusterTime" : Timestamp(0, 0),
        "signature" : {
            "hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
            "keyId" : NumberLong(0)
        }
    }
}

集群配置

config = {
"_id": "demo",
"members": [
{"_id": 0, "host": "127.0.0.1:40000"},
{"_id": 1, "host": "127.0.0.1:40001"},
{"_id": 2, "host": "127.0.0.1:40002", arbiterOnly: true}
]
}

rs.initiate(config)

查看状态

{
    "set" : "demo",
    "date" : ISODate("2018-11-01T07:55:22.492Z"),
    "myState" : 1,
    "term" : NumberLong(1),
    "syncingTo" : "",
    "syncSourceHost" : "",
    "syncSourceId" : -1,
    "heartbeatIntervalMillis" : NumberLong(2000),
    "optimes" : {
        "lastCommittedOpTime" : {
            "ts" : Timestamp(1541058909, 1),
            "t" : NumberLong(1)
        },
        "readConcernMajorityOpTime" : {
            "ts" : Timestamp(1541058909, 1),
            "t" : NumberLong(1)
        },
        "appliedOpTime" : {
            "ts" : Timestamp(1541058909, 1),
            "t" : NumberLong(1)
        },
        "durableOpTime" : {
            "ts" : Timestamp(1541058909, 1),
            "t" : NumberLong(1)
        }
    },
    "lastStableCheckpointTimestamp" : Timestamp(1541058907, 1),
    "members" : [
        {
            "_id" : 0,
            "name" : "127.0.0.1:40000",
            "health" : 1,
            "state" : 1,
            "stateStr" : "PRIMARY",
            "uptime" : 581,
            "optime" : {
                "ts" : Timestamp(1541058909, 1),
                "t" : NumberLong(1)
            },
            "optimeDate" : ISODate("2018-11-01T07:55:09Z"),
            "syncingTo" : "",
            "syncSourceHost" : "",
            "syncSourceId" : -1,
            "infoMessage" : "could not find member to sync from",
            "electionTime" : Timestamp(1541058906, 1),
            "electionDate" : ISODate("2018-11-01T07:55:06Z"),
            "configVersion" : 1,
            "self" : true,
            "lastHeartbeatMessage" : ""
        },
        {
            "_id" : 1,
            "name" : "127.0.0.1:40001",
            "health" : 1,
            "state" : 2,
            "stateStr" : "SECONDARY",
            "uptime" : 27,
            "optime" : {
                "ts" : Timestamp(1541058909, 1),
                "t" : NumberLong(1)
            },
            "optimeDurable" : {
                "ts" : Timestamp(1541058909, 1),
                "t" : NumberLong(1)
            },
            "optimeDate" : ISODate("2018-11-01T07:55:09Z"),
            "optimeDurableDate" : ISODate("2018-11-01T07:55:09Z"),
            "lastHeartbeat" : ISODate("2018-11-01T07:55:22.212Z"),
            "lastHeartbeatRecv" : ISODate("2018-11-01T07:55:20.813Z"),
            "pingMs" : NumberLong(0),
            "lastHeartbeatMessage" : "",
            "syncingTo" : "127.0.0.1:40000",
            "syncSourceHost" : "127.0.0.1:40000",
            "syncSourceId" : 0,
            "infoMessage" : "",
            "configVersion" : 1
        },
        {
            "_id" : 2,
            "name" : "127.0.0.1:40002",
            "health" : 1,
            "state" : 7,
            "stateStr" : "ARBITER",
            "uptime" : 27,
            "lastHeartbeat" : ISODate("2018-11-01T07:55:22.212Z"),
            "lastHeartbeatRecv" : ISODate("2018-11-01T07:55:21.154Z"),
            "pingMs" : NumberLong(0),
            "lastHeartbeatMessage" : "",
            "syncingTo" : "",
            "syncSourceHost" : "",
            "syncSourceId" : -1,
            "infoMessage" : "",
            "configVersion" : 1
        }
    ],
    "ok" : 1,
    "operationTime" : Timestamp(1541058909, 1),
    "$clusterTime" : {
        "clusterTime" : Timestamp(1541058909, 1),
        "signature" : {
            "hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
            "keyId" : NumberLong(0)
        }
    }
}

验证

mongo --port 40000

demo:PRIMARY> use test_db
switched to db test_db

demo:PRIMARY> db.user.insert({'name': 'xiaowang'})
WriteResult({ "nInserted" : 1 })

mongo --port 40001

demo:SECONDARY> use test_db
switched to db test_db

demo:SECONDARY> rs.secondaryOk()

demo:SECONDARY> db.user.find({})
{ "_id" : ObjectId("60927a5e92840a57d0e214da"), "name" : "xiaowang" }

参考

Mongo副本集
Mongo集群搭建