[Database] MongoDB 複本集配置

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MongoDB 複本集配置

MongoDB複製是將資料同步在多個伺服器的過程。
複製提供了資料的冗餘備份，並在多個伺服器上儲存資料副本，提高了資料的可用性， 並可以保證資料的安全性。
複製還允許您從硬體故障和服務中斷中恢複資料。

棄置站台集時注意

1. 版本: 各複本集伺服器的MongoDB版本一致或支援同樣的replSet功能
2. 網路: 複本集內的每個成員都必須能夠串連到其他成員(包括自身),啟動時注意bind_ip --bind_ip_all.

配置複本集

• 1 建立設定檔

mongodb.conf  1 # Start MongoDB as a daemon on port 27017                                                                                                                     2   3 port = 27017  4 fork = true  5 replSet = test_replica_set  6 dbpath = /datatest/db  7 logpath = /datatest/db/test.log  8 logappend = true  9 mongodb2.conf  2   3 port = 27017  4 fork = true  5 replSet = test_replica_set  6 dbpath = /datatest/db  7 logpath = /datatest/db/test.log  8 logappend = true  9 mongodb3.conf  2   3 port = 27017  4 fork = true  5 replSet = test_replica_set  6 dbpath = /datatest/db  7 logpath = /datatest/db/test.log  8 logappend = true  9 

• 2 啟動資料庫

mac-abeen:bin abeen$ sudo ./mongod -f mongodb.conf about to fork child process, waiting until server is ready for connections.forked process: 37181child process started successfully, parent exitingmac-abeen:bin abeen$ sudo ./mongod -f mongodb2.conf about to fork child process, waiting until server is ready for connections.forked process: 37185child process started successfully, parent exitingmac-abeen:bin abeen$ sudo ./mongod -f mongodb3.conf about to fork child process, waiting until server is ready for connections.forked process: 37189child process started successfully, parent exiting

• 3 初始化複本集

mac-abeen:bin abeen$ ./mongo --nodbMongoDB shell version: 3.2.8> config = {}{ }> config = {"_id": "test_replica_set", "members": [        {"_id": 0, "host": "192.168.0.10:27017"},         {"_id": 1, "host": "192.168.0.20:27017"},         {"_id": 2, "host": "192.168.0.30:27017"}]}{    "_id" : "test_replica_set",    "members" : [        {            "_id" : 0,            "host" : "192.168.0.10:27017"        },        {            "_id" : 1,            "host" : "192.168.0.20:27017"        },        {            "_id" : 2,            "host" : "192.168.0.30:27017"        }    ]}> db = (new Mongo("192.168.0.10:27017")).getDB("test")test> rs.initiate(config){ "ok" : 1 }test_replica_set:OTHER> test_replica_set:PRIMARY> rs.config(){    "_id" : "test_replica_set",    "version" : 1,    "protocolVersion" : NumberLong(1),    "members" : [        {            "_id" : 0,            "host" : "192.168.0.10:27017",            "arbiterOnly" : false,            "buildIndexes" : true,            "hidden" : false,            "priority" : 1,            "tags" : {                            },            "slaveDelay" : NumberLong(0),            "votes" : 1        },        {            "_id" : 1,            "host" : "192.168.0.20:27017",            "arbiterOnly" : false,            "buildIndexes" : true,            "hidden" : false,            "priority" : 1,            "tags" : {                            },            "slaveDelay" : NumberLong(0),            "votes" : 1        },        {            "_id" : 2,            "host" : "192.168.0.30:27017",            "arbiterOnly" : false,            "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("5850f445c8cacd70496883b0")    }}

• 4 寫入資料並查看複本集資料

test_replica_set:PRIMARY> test_replica_set:PRIMARY> for (i=0; i < 100; i++){db.coll.insert({"count": i})}WriteResult({ "nInserted" : 1 })test_replica_set:PRIMARY> db.coll.count()100test_replica_set:PRIMARY> db.coll.find().limit(5){ "_id" : ObjectId("5850f5f35f1a7d82c0b45b51"), "count" : 0 }{ "_id" : ObjectId("5850f5f35f1a7d82c0b45b52"), "count" : 1 }{ "_id" : ObjectId("5850f5f35f1a7d82c0b45b53"), "count" : 2 }{ "_id" : ObjectId("5850f5f35f1a7d82c0b45b54"), "count" : 3 }{ "_id" : ObjectId("5850f5f35f1a7d82c0b45b55"), "count" : 4 }

• 5 查看複本集是否有資料

mac-abeen:bin abeen$ ./mongo --port 27017 --host 192.168.0.20MongoDB shell version: 3.2.8connecting to: 192.168.0.20:27017/testtest_replica_set:SECONDARY> db.coll.find().limit(5)Error: error: { "ok" : 0, "errmsg" : "not master and slaveOk=false", "code" : 13435 }設定串連可讀取資料test_replica_set:SECONDARY> db.setSlaveOk()副本中已有資料 test_replica_set:SECONDARY> db.coll.find().limit(5){ "_id" : ObjectId("5850f5f35f1a7d82c0b45b53"), "count" : 2 }{ "_id" : ObjectId("5850f5f35f1a7d82c0b45b55"), "count" : 4 }{ "_id" : ObjectId("5850f5f35f1a7d82c0b45b52"), "count" : 1 }{ "_id" : ObjectId("5850f5f35f1a7d82c0b45b54"), "count" : 3 }{ "_id" : ObjectId("5850f5f35f1a7d82c0b45b51"), "count" : 0 }

修改複本集

rs.add("server-4:27017")    //添加rs.addArb("server-4:27017") //添加選舉仲裁者rs.add({"_id": 4, "host": "server-4:27017", "arbiterOnly": true) //添加選舉仲裁者rs.add({"_id": 5, "host": "server-5:27017", "priority": 0, "hidden": true) //添加隱藏成員rs.remove("server-4:27017") //移除

修改複本集,通過rs.reconfig

rs.reconfig修改複本集成員時限制

• 不能修改成員的_id 欄位
• 不能將接收rs.reconfig命令的成員(通常是主節點)的優先順序設為0
• 不能仲裁者成員變為非仲裁者成員,反之亦然.
• 不能將buildIndexes: false的成員修改為buildIndexes: true
  可以修改其他,比如host

var config = rs.config()config.members[1].host = "newsserver:27017" //修改hostrs.reconfig(config)

[Database] MongoDB 複本集配置