MongDB4.2.7分片副本集集群 · Linux學習手冊

[TOC] # MongDB分片副本集集群副本集解決主節點發生故障導致數據丟失或不可用的問題，但遇到需要存儲海量數據的情況時，副本集機制就束手無策了。副本集中的一臺機器可能不足以存儲數據，或者說集群不足以提供可接受的讀寫吞吐量。這就需要用到 MongoDB 的分片（Sharding）技術，這也是 MongoDB 的另外一種集群部署模式。分片是指將數據拆分并分散存放在不同機器上的過程。有時也用分區來表示這個概念。將數據分散到不同的機器上，不需要功能強大的大型計算機就可以存儲更多的數據，處理更大的負載。 MongoDB 支持自動分片，可以使數據庫架構對應用程序不可見，簡化系統管理。對應用程序而言，就如同始終在使用一個單機的 MongoDB 服務器一樣。 MongoDB 的分片機制允許創建一個包含許多臺機器的集群，將數據子集分散在集群中，每個分片維護著一個數據集合的子集。與副本集相比，使用集群架構可以使應用程序具有更強大的數據處理能力。下圖展示了在MongoDB中使用分片集群結構分布： ![image](http://yanxuan.nosdn.127.net/c210a44615a3928580f85e7660c1e1fd.png) 上圖中主要有如下所述三個主要組件： - Shard: 用于存儲實際的數據塊，實際生產環境中一個shard server角色可由幾臺機器組個一個relica set承擔，防止主機單點故障 - Config Server: mongod實例，存儲了整個 ClusterMetadata，其中包括 chunk信息。4.0版本以后要求最低3個副本集 - Query Routers: 前端路由，客戶端由此接入，且讓整個集群看上去像單一數據庫，前端應用可以透明使用。 # 開始搭建準備三臺機器，這里用的三臺虛擬機系統： CentOS-7.2 軟件： MongDB-4.2.7 role/port | 192.168.0.41 | 192.168.0.42 | 192.168.0.43 ---|---|---|--- config | 30000 | 30000 | 30000 mongos | 30010 | 30010 | 30010 shard1 | 27001 | 27001 | 27001 shard2 | 27002 | 27002 | 27002 shard3 | 27003 | 27003 | 27003 官網新版本配置文件說明： [https://docs.mongodb.com/manual/reference/configuration-options/](https://note.youdao.com/) ## config集群 1. 創建文件及文件夾 ``` [root@localhost /]# mkdir -p /usr/local/mongodb/data/config [root@localhost /]# mkdir -p /usr/local/mongodb/log/config [root@localhost /]# touch /usr/local/mongodb/log/config.log ``` 2. 創建config.cfg ``` [root@localhost /]# cat /usr/local/mongodb/conf/config.cfg systemLog: destination: file logAppend: true path: /usr/local/mongodb/log/config.log storage: dbPath: /usr/local/mongodb/data/config journal: enabled: true # engine: # wiredTiger: processManagement: fork: true # fork and run in background #pidFilePath: /var/run/mongodb/config1.pid # location of pidfile timeZoneInfo: /usr/share/zoneinfo # network interfaces net: port: 30000 bindIp: 0.0.0.0 #security: # authorization: enabled # keyFile: /usr/local/mongodb/conf/mongodb.keyfile #operationProfiling: replication: replSetName: configs sharding: clusterRole: configsvr ## Enterprise-Only Options #auditLog: #snmp: ``` 3. 啟動config ``` [root@localhost mongodb]# mongod -f /usr/local/mongodb/conf/config.cfg about to fork child process, waiting until server is ready for connections. forked process: 223 child process started successfully, parent exiting ``` ps: 30000端口成功監聽另外2臺的操作同上 4. 創建config集群任意一臺機器上操作 ``` [root@localhost mongodb]# mongo --port 30000 > rs.initiate( { _id: "configs", configsvr: true, members: [ { _id : 0, host : "192.168.0.41:30000" }, { _id : 1, host : "192.168.0.42:30000" }, { _id : 2, host : "192.168.0.43:30000" }, ] } ) "ok" : 1, "$gleStats" : { "lastOpTime" : Timestamp(1591233702, 1), "electionId" : ObjectId("000000000000000000000000") }, "lastCommittedOpTime" : Timestamp(0, 0), "$clusterTime" : { "clusterTime" : Timestamp(1591233702, 1), "signature" : { "hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="), "keyId" : NumberLong(0) } }, "operationTime" : Timestamp(1591233702, 1) } ``` ps: 初始化id必須要和config.cfg內定義的replSetName相同才能成功 rs.status() 查看集群狀態 ## shard分片集群 1. 創建文件及文件夾 ``` [root@localhost /]# mkdir -p /usr/local/mongodb/data/shard{1..3} [root@localhost /]# mkdir -p /usr/local/mongodb/log/shard{1..3} [root@localhost /]# touch /usr/local/mongodb/log/shard{1..3}/shard.log ``` 2. 創建shard1.cfg，shard2.cfg，shard3.cfg ``` [root@localhost /]# cat /usr/local/mongodb/conf/shard1.cfg systemLog: destination: file logAppend: true path: /usr/local/mongodb/log/shard1/shard.log storage: dbPath: /usr/local/mongodb/data/shard1 journal: enabled: true # engine: # wiredTiger: processManagement: fork: true # fork and run in background #pidFilePath: /var/run/mongodb/shard1.pid # location of pidfile timeZoneInfo: /usr/share/zoneinfo net: port: 27001 bindIp: 0.0.0.0 #security: # authorization: enabled # keyFile: /usr/local/mongodb/conf/mongodb.keyfile #operationProfiling: replication: replSetName: shard1 sharding: clusterRole: shardsvr ## Enterprise-Only Options #auditLog: #snmp: [root@localhost /]# cat /usr/local/mongodb/conf/shard2.cfg systemLog: destination: file logAppend: true path: /usr/local/mongodb/log/shard2/shard.log storage: dbPath: /usr/local/mongodb/data/shard2 journal: enabled: true # engine: # wiredTiger: processManagement: fork: true # fork and run in background #pidFilePath: /var/run/mongodb/shard1.pid # location of pidfile timeZoneInfo: /usr/share/zoneinfo net: port: 27002 bindIp: 0.0.0.0 #security: #operationProfiling: replication: replSetName: shard2 sharding: clusterRole: shardsvr ## Enterprise-Only Options #auditLog: #snmp: ``` shard3.cfg參考shard2.cfg 3. 啟動shard ``` [root@localhost mongodb]# mongod -f /usr/local/mongodb/conf/shard1.cfg [root@localhost mongodb]# mongod -f /usr/local/mongodb/conf/shard2.cfg [root@localhost mongodb]# mongod -f /usr/local/mongodb/conf/shard3.cfg ``` 另外2臺的操作同上 4. 創建shard集群任意一臺機器上執行 ``` [root@localhost mongodb]# mongo --port 27001 > rs.initiate( { _id: "shard1", members: [ { _id : 0, host : "192.168.0.41:27001" }, { _id : 1, host : "192.168.0.42:27001" }, { _id : 2, host : "192.168.0.43:27001" }, ] } ) [root@localhost mongodb]# mongo --port 27002 > rs.initiate( { _id: "shard2", members: [ { _id : 0, host : "192.168.0.41:27002" }, { _id : 1, host : "192.168.0.42:27002" }, { _id : 2, host : "192.168.0.43:27002" }, ] } ) [root@localhost mongodb]# mongo --port 27003 > rs.initiate( { _id: "shard3", members: [ { _id : 0, host : "192.168.0.41:27003" }, { _id : 1, host : "192.168.0.42:27003" }, { _id : 2, host : "192.168.0.43:27003" }, ] } ) ``` 目前已經創建了shard1，shard2，shard3三個具有三副本的復制集，后續還會創建分片集群 ## mongos服務 1. 準備文件 monogs作為集群訪問的入口，是不存儲數據的，只需要創建日志文件。每個服務器上啟動一個mongos，提高可用性。 ``` [root@localhost mongodb]# touch /usr/local/mongodb/log/mongos.log ``` 2. 創建mongos.cfg ``` [root@localhost /]# cat /usr/local/mongodb/conf/mongos.cfg systemLog: destination: file logAppend: true path: /usr/local/mongodb/log/mongos.log processManagement: fork: true # fork and run in background #pidFilePath: /var/run/mongodb/mongos1.pid # location of pidfile timeZoneInfo: /usr/share/zoneinfo net: port: 30010 bindIp: 0.0.0.0 #security: #operationProfiling: #eplication: sharding: # 配置哪些ip 需要添加 #configDB: configs/192.168.0.153:30000,192.168.0.216:30000,192.168.0.218:30000 configDB: configs/192.168.0.41:30000,192.168.0.42:30000,192.168.0.43:30000 # clusterRole: configsvr ## Enterprise-Only Options #auditLog: #snmp: ``` ps: configDB指向三個config服務的地址和端口 3. 啟動mongos ``` [root@localhost mongodb]# mongos -f /usr/local/mongodb/conf/mongos.cfg ``` ps：mongos啟動不是使用mongod 每臺機器都要啟動一個mongos服務 ## 為各副本集添加秘鑰認證 1. 生成秘鑰文件任意一臺機器操作 ``` [root@localhost mongodb]# openssl rand 700 -base64 > /usr/local/mongodb/conf/mongodb.keyfile [root@localhost mongodb]# chmod 600 /usr/local/mongodb/conf/mongodb.keyfile ``` 2. 將秘鑰分發到其他服務器 ``` [root@localhost mongodb]# scp /usr/local/mongodb/conf/mongodb.keyfile root@192.168.0.42:/usr/local/mongodb/conf [root@localhost mongodb]# scp /usr/local/mongodb/conf/mongodb.keyfile root@192.168.0.43:/usr/local/mongodb/conf ``` 3. 修改配置文件 config.cfg，shard.cfg，mongos.cfg三類文件新增以下內容 ``` security: keyFile: /usr/local/mongodb/conf/mongodb.keyfile ``` ## 創建用于連接的用戶 1. 命令行創建用戶 ``` mongos> use admin switched to db admin mongos> db.createUser({user:"mongouser",pwd:"mongopwd",roles:["root"]}) mongos> db.auth("mongouser","mongopwd") mongos> use config switched to db config mongos> db.createUser({user:"mongouser",pwd:"mongopwd",roles:["root"]}) mongos> db.auth("mongouser","mongopwd") ``` 2. 修改配置文件 config.cfg，shard.cfg兩類文件新增以下內容 ``` security: authorization: enabled ``` 3. 重啟服務mongo服務 4. 客戶端連接 5. 用戶管理常用命令 - show users // 查看當前庫下的用戶 - db.dropUser('testadmin') // 刪除用戶 - db.updateUser('admin', {pwd: '654321'}) // 修改用戶密碼 - db.auth('admin', '654321') // 密碼認證 ## 可能遇到的問題 1. 啟用認證后，遇到"command replSetGetStatus requires authentication" ``` configs:SECONDARY> rs.status() { "operationTime" : Timestamp(1591253807, 2), "ok" : 0, "errmsg" : "command replSetGetStatus requires authentication", "code" : 13, "codeName" : "Unauthorized", "lastCommittedOpTime" : Timestamp(1591253807, 2), "$clusterTime" : { "clusterTime" : Timestamp(1591253807, 2), "signature" : { "hash" : BinData(0,"QCmeAVDoq7jZzwHfPYNn/mU4eS8="), "keyId" : NumberLong("6834296761922617360") } } } configs:SECONDARY> use admin switched to db admin configs:SECONDARY> db.auth('mongouser','mongopwd') 1 ``` 2. 啟動mongos實例一直無響應 - 可能是啟動順序，需要啟動config實例后操作 - 認證秘鑰問題 # 使用實例 1. 連接mongos 任意一臺上連接 ``` [root@localhost mongodb]# mongo --port 30010 ``` 2. 添加分片 ``` mongos> use admin switched to db admin mongos> sh.addShard("shard1/192.168.0.41:27001,192.168.0.42:27001,192.168.0.43:27001") { "shardAdded" : "shard1", "ok" : 1, "operationTime" : Timestamp(1591241739, 4), "$clusterTime" : { "clusterTime" : Timestamp(1591241739, 4), "signature" : { "hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="), "keyId" : NumberLong(0) } } } mongos> sh.addShard("shard2/192.168.0.41:27002,192.168.0.42:27002,192.168.0.43:27002") { "shardAdded" : "shard2", "ok" : 1, "operationTime" : Timestamp(1591241810, 2), "$clusterTime" : { "clusterTime" : Timestamp(1591241810, 2), "signature" : { "hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="), "keyId" : NumberLong(0) } } } mongos> sh.addShard("shard3/192.168.0.41:27003,192.168.0.42:27003,192.168.0.43:27003") { "shardAdded" : "shard3", "ok" : 1, "operationTime" : Timestamp(1591241833, 6), "$clusterTime" : { "clusterTime" : Timestamp(1591241833, 6), "signature" : { "hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="), "keyId" : NumberLong(0) } } } ``` - 查看分片狀態 sh.status() - 移除分片 db.runCommand({removeShard : "shard1"}) 3. 開啟數據庫分片（創建數據庫） ``` mongos> use admin mongos> sh.enableSharding("notice_set") ``` 4. 指定數據庫表中的字段key為分片鍵，并對其使用哈希分片策略 ``` mongos> sh.shardCollection("notice_set.notice",{"msgid": "hashed"}) ``` 5. 添加測試數據 ``` mongos> use notice_set mongos> for (i = 1; i <= 10; i++) db.notice.insert({"msgid":i}) ``` 可以查看每個分片的數據量等于10 # 連接集群的方式 1. 單機連接選任一mongos直接連接，如果該mongos不可用，服務也無法繼續使用 ``` mongos --host --port ``` 2. 集群連接配置上所有mongos，某一個mongos不可用，服務將繼續 ``` mongodb://[username:password@]host1[:port1][,host2[:port2],...[,hostN[:portN]]][/[database][?options]] ``` - mongodb:// 前綴，代表這是一個Connection String - username:password@ 如果啟用了鑒權，需要指定用戶密碼 - hostX:portX 多個 mongos 的地址列表 - /database 鑒權時，用戶帳號所屬的數據庫 - ?options 指定額外的連接選項