在自己的本機(jī)創(chuàng)建有三個節(jié)點(diǎn)的副本集 (一個主節(jié)點(diǎn)，兩個從節(jié)點(diǎn))，是基于MongoDB 3.6 版本

• 創(chuàng)建數(shù)據(jù)存儲路徑

  mkdir r0
  mkdir r1
  mkdir r2
  

• 創(chuàng)建log存儲路徑

  mkdir log
  

• 啟動第一個節(jié)點(diǎn)

  mongod --replSet rs0 --port 27017 --bind_ip 127.0.0.1 --dbpath .\r0\ --logpath log\r0.log --logappend
  

• 啟動第二個節(jié)點(diǎn)

  mongod --replSet rs0 --port 27018 --bind_ip 127.0.0.1 --dbpath .\r1\ --logpath log\r1.log --logappend
  

• 啟動第三個節(jié)點(diǎn)

  mongod --replSet rs0 --port 27017 --bind_ip 127.0.0.1 --dbpath .\r2\ --logpath log\r2.log --logappend
  

• 連接到 mongod 實(shí)例

  mongo --port 27017
  

• 在 mongo shell中，使用 rs.initiate() 初始化副本集

rsconf = {
  _id: "rs0",
  members: [
    {
     _id: 0,
     host: "127.0.1:27017"
    },
    {
     _id: 1,
     host: "127.0.1:27018"
    },
    {
     _id: 2,
     host: "127.0.1:27019"
    }
   ]
}
rs.initiate(rsconf)

初始化成功

{
        "ok" : 1,
        "operationTime" : Timestamp(1524728214, 1),
        "$clusterTime" : {
                "clusterTime" : Timestamp(1524728214, 1),
                "signature" : {
                        "hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
                        "keyId" : NumberLong(0)
                }
        }
}

• 查看副本集的狀態(tài)
  27017:是主節(jié)點(diǎn)
  27018 27019是從節(jié)點(diǎn)

  rs.status()
  {
        "set" : "rs0",
        "date" : ISODate("2018-04-26T08:15:11.241Z"),
        "myState" : 1,
        ...
        "members" : [
                {
                        "_id" : 0,
                        "name" : "127.0.0.1:27017",
                        "health" : 1,
                        "state" : 1,
                        "stateStr" : "PRIMARY",
                        ...
                },
                {
                        "_id" : 1,
                        "name" : "127.0.0.1:27018",
                        "health" : 1,
                        "state" : 2,
                        "stateStr" : "SECONDARY",
                         ...
                },
                {
                        "_id" : 2,
                        "name" : "127.0.0.1:27019",
                        "health" : 1,
                        "state" : 2,
                        "stateStr" : "SECONDARY",
                        ...
                }
        ],
        "ok" : 1,
        ...
    }
  

• 查看節(jié)點(diǎn)是否是主節(jié)點(diǎn)

rs.isMaster()
{
                "hosts" : [
                        "127.0.0.1:27017",
                        "127.0.0.1:27018",
                        "127.0.0.1:27019"
                ],
                "setName" : "rs0",
                "setVersion" : 1,
                "ismaster" : true,
                "secondary" : false,
                "primary" : "127.0.0.1:27017",
                "me" : "127.0.0.1:27017",
                "electionId" : ObjectId("7fffffff0000000000000003"),
               ...
        }

• 讀寫操作
  先在主節(jié)點(diǎn)創(chuàng)建一個數(shù)據(jù)庫并寫入數(shù)據(jù)

  use TestDB  
  db.createCollection("TestModel")  
  db.getCollection("TestModel").insert({"first_name":"Lorry","second_name":"kevin"})
  

使用從節(jié)點(diǎn)進(jìn)行查詢

mongo --port 27019

無法進(jìn)行查詢的操作 ,從節(jié)點(diǎn)無法進(jìn)行查詢操作

rs0:SECONDARY> show dbs
2018-04-26T16:20:35.769+0800 E QUERY    [thread1] Error: listDatabases failed:{
      "operationTime" : Timestamp(1524730833, 1),
      "ok" : 0,
      "errmsg" : "not master and slaveOk=false",
      "code" : 13435,
      "codeName" : "NotMasterNoSlaveOk",
      ...
} :

配置從節(jié)點(diǎn)可以進(jìn)行查詢

db.getMongo().setSlaveOk()

rs0:SECONDARY> show dbs
TestDB  0.000GB
admin   0.000GB
config  0.000GB
local   0.000GB

• 故障轉(zhuǎn)移

  把主節(jié)點(diǎn)端口停掉，再查看對應(yīng)的副本集的狀態(tài)
  rs.status()

  27017 ： "stateStr" : "(not reachable/healthy)"  
  27018 ： "stateStr" : "PRIMARY",  
  27019 : "stateStr" : "SECONDARY",  

  27018 變成了主節(jié)點(diǎn)  
 {
        "set" : "rs0",
        "date" : ISODate("2018-04-26T08:24:24.740Z"),
        "myState" : 2,
        "term" : NumberLong(4),
        ...
        "members" : [
                {
                        "_id" : 0,
                        "name" : "127.0.0.1:27017",
                        "health" : 0,
                        "state" : 8,
                        "stateStr" : "(not reachable/healthy)",
                        ...
                },
                {
                        "_id" : 1,
                        "name" : "127.0.0.1:27018",
                        "health" : 1,
                        "state" : 1,
                        "stateStr" : "PRIMARY",
                        ...
                },
                {
                        "_id" : 2,
                        "name" : "127.0.0.1:27019",
                        "health" : 1,
                        "state" : 2,
                        "stateStr" : "SECONDARY",
                       ...
                }
        ],
        "ok" : 1,
        ...
}

• 增加節(jié)點(diǎn)

  mkdir r3
  

• 啟動新節(jié)點(diǎn)

  mongod --relpSet rs0 --port 27020 --bind_ip 127.0.0.1 --dbpath .\r3\
  

  增加節(jié)點(diǎn)

  rs.add("127.0.0.1:27020")
  {
        "ok" : 1,
        "operationTime" : Timestamp(1524731467, 1),
        "$clusterTime" : {
                "clusterTime" : Timestamp(1524731467, 1),
                "signature" : {
                        "hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
                        "keyId" : NumberLong(0)
                }
        }
  }
  

在查看副本集的狀態(tài)，可以看到 27020的新節(jié)點(diǎn)， 連接到新的節(jié)點(diǎn)查看，數(shù)據(jù)已經(jīng)同步了

• 刪除節(jié)點(diǎn)

rs.remove("127.0.0.1:27020")

  {
          "ok" : 1,
          "operationTime" : Timestamp(1524731753, 1),
          "$clusterTime" : {
                  "clusterTime" : Timestamp(1524731753, 1),
                  "signature" : {
                          "hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
                          "keyId" : NumberLong(0)
                  }
          }
  }

再查看一下當(dāng)前副本集的狀態(tài)，可以看到 27020的節(jié)點(diǎn)已經(jīng)被刪除了