每天一篇，深入學習MongoDB複製集

標籤：collect   多執行個體   服務   path   eid   commit   刪除節點   讀取資料   started   

複製集概念：

複製集是額外的資料副本，是跨多個伺服器同步資料的過程，提供了冗餘並增加了資料的可用性，通過它可以對硬體故障和中斷的服務進行資料恢複

複製集工作原理：

MongoDB複製集最少需要兩個節點。主節點：負責處理用戶端的請求，從節點：負責複製主節點上的資料搭配方式：一主一從或一主多從註：用戶端在主節點寫入資料，在從節點讀取資料，主從進行資料互動，保證資料的一致性

MongoDB複製集部署（1）配置複製集

[[email protected] ~]# mkdir -p /data/moongodb/mongodb{2,3,4}   //建立多執行個體[[email protected] ~]# cd /data/mongodb/[[email protected] mongodb]# mongo  mongod2.log  mongodb2  mongodb3  mongodb4[[email protected] mongodb]# mkdir logs[[email protected] mongodb]# lslogs  mongo  mongodb2  mongodb3  mongodb4[[email protected] mongodb]# touch logs/mongodb{2,3,4}.log[[email protected] mongodb]# cd logs/[[email protected] logs]# lsmongodb2.log  mongodb3.log  mongodb4.log[[email protected] logs]# chmod 777 *.log  //賦予最大許可權[[email protected] logs]# lsmongodb2.log  mongodb3.log  mongodb4.log[[email protected] logs]# ll總用量 0-rwxrwxrwx. 1 root root 0 7月  17 08:59 mongodb2.log-rwxrwxrwx. 1 root root 0 7月  17 08:59 mongodb3.log-rwxrwxrwx. 1 root root 0 7月  17 08:59 mongodb4.log

（2）編輯4個MongoDB執行個體的設定檔

[[email protected] etc]# vim mongod.confreplication:                    //注釋此項  replSetName: root123         //添加複製集名稱（自取），注意前面空兩格  [[email protected] etc]# mongod -f /etc/mongod.conf  --shutdown  //關閉服務killing process with pid: 1084[[email protected] etc]# mongod -f /etc/mongod.conf  //開啟服務about to fork child process, waiting until server is ready for connections.forked process: 11329child process started successfully, parent exiting註：修改設定檔後需重啟服務，檔案生效[[email protected] etc]# cp -p mongod.conf mongod2.conf cp：是否覆蓋"mongod2.conf"？ y[[email protected] etc]# vim mongod2.confpath:/data/mongodb/logs/mongodb2.log        //日誌存放位置dbpath:/data/mongodb/mongodb2               //資料存放位置port：                                      //修改連接埠號碼，連接埠號碼不能相同[[email protected] etc]# cp -p mongod2.conf mongod3.conf  [[email protected] etc]# cp -p mongod2.conf mongod4.conf [[email protected] etc]# vim mongod3.conf         //改序號和連接埠號碼即可，其它和2相同配置[[email protected] etc]# vim mongod4.conf [[email protected] etc]# mongod -f /etc/mongod2.conf[[email protected] etc]# mongod -f /etc/mongod3.conf[[email protected] etc]# mongod -f /etc/mongod4.conf[[email protected] etc]# netstat -antp | grep mongod      //四台執行個體都已開啟tcp        0      0 0.0.0.0:27019           0.0.0.0:*               LISTEN      11599/mongod        tcp        0      0 0.0.0.0:27020           0.0.0.0:*               LISTEN      11627/mongod        tcp        0      0 0.0.0.0:27017           0.0.0.0:*               LISTEN      11459/mongod        tcp        0      0 0.0.0.0:27018           0.0.0.0:*               LISTEN      10252/mongod

（3）配置三個節點的複製集

[[email protected] etc]# systemctl stop firewalld.service    //關閉防火牆[[email protected] etc]# setenforce 0[[email protected] etc]#mongo> show dbs> cfg={"_id":"root123","members":[{"_id":0,"host":"192.168.200.184:27017"},{"_id":1,"host":"192.168.200.184:27018"},{"_id":2,"host":"192.168.200.184:27019"}]}                             //配置節點複製集{    "_id" : "root123",    "members" : [        {            "_id" : 0,            "host" : "192.168.200.184:27017"        },        {            "_id" : 1,            "host" : "192.168.200.184:27018"        },        {            "_id" : 2,            "host" : "192.168.200.184:27019"        }    ]}> db.stats()                                       {    "db" : "test",    "collections" : 0,    "views" : 0,    "objects" : 0,    "avgObjSize" : 0,    "dataSize" : 0,    "storageSize" : 0,    "numExtents" : 0,    "indexes" : 0,    "indexSize" : 0,    "fileSize" : 0,    "fsUsedSize" : 0,    "fsTotalSize" : 0,    "ok" : 1,                                  //狀態ok=1，複製成功    "$clusterTime" : {        "clusterTime" : Timestamp(0, 0),        "signature" : {            "hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),            "keyId" : NumberLong(0)        }    }}123:SECONDARY> rs.status()                  //查看複製集狀態{    "set" : "root123",    "date" : ISODate("2018-07-17T03:24:03.253Z"),    "myState" : 1,    "term" : NumberLong(1),    "syncingTo" : "",    "syncSourceHost" : "",    "syncSourceId" : -1,    "heartbeatIntervalMillis" : NumberLong(2000),    "optimes" : {        "lastCommittedOpTime" : {            "ts" : Timestamp(1531797840, 1),            "t" : NumberLong(1)        },        "readConcernMajorityOpTime" : {            "ts" : Timestamp(1531797840, 1),            "t" : NumberLong(1)        },        "appliedOpTime" : {            "ts" : Timestamp(1531797840, 1),            "t" : NumberLong(1)        },        "durableOpTime" : {            "ts" : Timestamp(1531797840, 1),            "t" : NumberLong(1)        }    },    "members" : [        {            "_id" : 0,            "name" : "192.168.200.184:27017",            "health" : 1,            "state" : 1,            "stateStr" : "PRIMARY",                //狀態1為主            "uptime" : 980,            "optime" : {                "ts" : Timestamp(1531797840, 1),                "t" : NumberLong(1)            },            "optimeDate" : ISODate("2018-07-17T03:24:00Z"),            "syncingTo" : "",            "syncSourceHost" : "",            "syncSourceId" : -1,            "infoMessage" : "could not find member to sync from",            "electionTime" : Timestamp(1531797808, 1),            "electionDate" : ISODate("2018-07-17T03:23:28Z"),            "configVersion" : 1,            "self" : true,            "lastHeartbeatMessage" : ""        },        {            "_id" : 1,            "name" : "192.168.200.184:27018",            "health" : 1,            "state" : 2,                    "stateStr" : "SECONDARY",               //狀態2為從            "uptime" : 45,            "optime" : {                "ts" : Timestamp(1531797840, 1),                "t" : NumberLong(1)            },            "optimeDurable" : {                "ts" : Timestamp(1531797840, 1),                "t" : NumberLong(1)            },            "optimeDate" : ISODate("2018-07-17T03:24:00Z"),            "optimeDurableDate" : ISODate("2018-07-17T03:24:00Z"),            "lastHeartbeat" : ISODate("2018-07-17T03:24:02.633Z"),            "lastHeartbeatRecv" : ISODate("2018-07-17T03:24:02.920Z"),            "pingMs" : NumberLong(0),            "lastHeartbeatMessage" : "",            "syncingTo" : "192.168.200.184:27017",            "syncSourceHost" : "192.168.200.184:27017",            "syncSourceId" : 0,            "infoMessage" : "",            "configVersion" : 1        },        {            "_id" : 2,            "name" : "192.168.200.184:27019",            "health" : 1,            "state" : 2,            "stateStr" : "SECONDARY",              //狀態2為從            "uptime" : 45,            "optime" : {                "ts" : Timestamp(1531797840, 1),                "t" : NumberLong(1)            },            "optimeDurable" : {                "ts" : Timestamp(1531797840, 1),                "t" : NumberLong(1)            },            "optimeDate" : ISODate("2018-07-17T03:24:00Z"),            "optimeDurableDate" : ISODate("2018-07-17T03:24:00Z"),            "lastHeartbeat" : ISODate("2018-07-17T03:24:02.633Z"),            "lastHeartbeatRecv" : ISODate("2018-07-17T03:24:02.896Z"),            "pingMs" : NumberLong(0),            "lastHeartbeatMessage" : "",            "syncingTo" : "192.168.200.184:27017",            "syncSourceHost" : "192.168.200.184:27017",            "syncSourceId" : 0,            "infoMessage" : "",            "configVersion" : 1        }    ],    "ok" : 1,    "operationTime" : Timestamp(1531797840, 1),    "$clusterTime" : {        "clusterTime" : Timestamp(1531797840, 1),        "signature" : {            "hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),            "keyId" : NumberLong(0)        }    }}root123:PRIMARY>            //最後顯示此狀態注:初始化配置時保證從節點沒有資料

（4）添加和刪除節點

root123:PRIMARY> rs.add("192.168.200.184:27020"){    "ok" : 1,    "operationTime" : Timestamp(1531799035, 1),    "$clusterTime" : {        "clusterTime" : Timestamp(1531799035, 1),        "signature" : {            "hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),            "keyId" : NumberLong(0)        }    }}root123:PRIMARY> rs.stats()"_id" : 3,            "name" : "192.168.200.184:27020",     //添加成功            "health" : 1,            "state" : 2,            "stateStr" : "SECONDARY",             //也為從節點            "uptime" : 26,            "optime" : {                "ts" : Timestamp(1531799060, 1),                "t" : NumberLong(1)            },root123:PRIMARY> rs.remove("192.168.200.184:27020"){    "ok" : 1,                                   //刪除成功    "operationTime" : Timestamp(1531799257, 1),    "$clusterTime" : {        "clusterTime" : Timestamp(1531799257, 1),        "signature" : {            "hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),            "keyId" : NumberLong(0)        }    }}

（5）類比故障自動轉移

[[email protected] mongodb]# ps aux | grep mongodroot      12342  1.3  5.8 1465664 58768 ?       Sl   11:07   0:38 mongod -f /etc/mongod3.confroot      12387  1.0  5.9 1442988 59124 ?       Sl   11:07   0:29 mongod -f /etc/mongod4.confroot      12428  1.4  6.4 1582772 64516 ?       Sl   11:07   0:40 mongod -f /etc/mongod.confroot      12667  1.5  6.2 1459800 62268 ?       Sl   11:17   0:35 mongod -f /etc/mongod2.confroot      13655  0.0  0.0 112676   984 pts/0    S+   11:55   0:00 grep --color=auto mongod[[email protected] mongodb]# kill -9 12428[[email protected] mongodb]# mongoroot123:SECONDARY> rs.status()"members" : [        {            "_id" : 0,            "name" : "192.168.200.184:27017",            "health" : 0,                  //第一台健康值為0，已經不存在            "state" : 8,            "stateStr" : "(not reachable/healthy)",            "uptime" : 0,            "optime" : {                "ts" : Timestamp(0, 0),                "t" : NumberLong(-1)            },            "optimeDurable" : {                "ts" : Timestamp(0, 0),                "t" : NumberLong(-1)            },{            "_id" : 2,            "name" : "192.168.200.184:27019",            "health" : 1,            "state" : 1,            "stateStr" : "PRIMARY",         //27019跳為主節點                    "uptime" : 2039,            "optime" : {                "ts" : Timestamp(1531799828, 1),                "t" : NumberLong(2)            },            "optimeDurable" : {                "ts" : Timestamp(1531799828, 1),                "t" : NumberLong(2)            },

多學多練，快樂無限~！！！

每天一篇，深入學習MongoDB複製集