Mongo 4.2.8 複製集搭建

環境

因資源有限，故本實驗是在同一臺機器上創建不同實例來完成

master：192.168.65.130  port：27018

secondary：192.168.65.130  port：27019

arbiter：192.168.65.130  port：27020

 

多實例安裝

方法與單實例基本相同，參考 https://blog.csdn.net/qq_31144297/article/details/107012909

配置文件

dbpath=/mongodb/27018/data
logpath=/mongodb/27018/logs/mongodb.log
port=27018
fork=true
#auth=true
#noauth=true
#verbose=true
#vvvv=true
journal=true
maxConns=500
logappend=true
directoryperdb=true
pidfilepath=/tmp/mongo_27018.pid
#cpu=true
#nohttpinterface=false
#notablescan=false
#profile=0
#slowms=200
#quiet=true
#syncdelay=60
replSet=ty
bind_ip=127.0.0.1,192.168.65.130


ps：replSet 爲複製集名稱，所有實例的該值一定要相同

將其中的文件路徑和端口相關的值修改爲對應的實例即可。

啓動實例

mongod --config /mongodb/27018/logs/mongodb.log

mongod --config /mongodb/27019/logs/mongodb.log

mongod --config /mongodb/27020/logs/mongodb.log

初始化主節點

rs.initiate({_id:'ty',members:[{_id:1,host:'192.168.65.130:27018'}]})

添加節點及仲裁節點

rs.add("192.168.65.130:27019")

rs.addArb("192.168.65.130:27020")

PS：或者以上2可以合成一步,如下：

 mongo -port 27018
> cfg={ _id:"rss", members:[ {_id:0,host:'192.168.65.130:27018',priority:2}, {_id:1,host:'192.168.65.130:27019',priority:1}, {_id:2,host:'192.168.65.130:27020',arbiterOnly:true}] };
初始化：> rs.initiate(cfg)

查看配置

rs.conf()

檢查各個節點local庫信息

複製集工作原理：

複製集通過local庫下的oplog.rs集合進行數據同步。

oplog會包含所有對數據有修改的操作（查詢操作不會記錄）

mongo 192.168.65.130:27019

use local

show collections



mongo 192.168.65.130:27020

use local

show collections

檢查複製集狀態

rs.status()

數據驗證

主庫添加數據

[mongodb@ty1 ~]$ mongo --port 27018
ty:PRIMARY> db.ty.insert({age:100})
WriteResult({ "nInserted" : 1 })
ty:PRIMARY> db.ty.find()
{ "_id" : ObjectId("5ef9a99662e0d2208ccde0cc"), "ty" : 11 }
{ "_id" : ObjectId("5efa8adc3b55e73f44c6539e"), "age" : 100 }

從庫查詢

[mongodb@ty1 ~]$ mongo --port 27019

ty:SECONDARY> db.ty.find()
Error: error: {
    "operationTime" : Timestamp(1593477663, 1),
    "ok" : 0,
    "errmsg" : "not master and slaveOk=false",
    "code" : 13435,
    "codeName" : "NotMasterNoSlaveOk",
    "$clusterTime" : {
        "clusterTime" : Timestamp(1593477663, 1),
        "signature" : {
            "hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
            "keyId" : NumberLong(0)
        }
    }
}
如果出現上面的提示：not master and slaveOkfalse

則執行 db.getMongo().setSlaveOk()

然後在查詢

ty:SECONDARY> db.ty.find()
{ "_id" : ObjectId("5ef9a99662e0d2208ccde0cc"), "ty" : 11 }
{ "_id" : ObjectId("5efa8adc3b55e73f44c6539e"), "age" : 100 }

故障轉移

1.記錄故障轉移之前的狀態

"members" : [
		{
			"_id" : 1,
			"name" : "192.168.65.130:27018",
			"health" : 1,
			"state" : 1,
			"stateStr" : "PRIMARY",
			"uptime" : 58483,
			"optime" : {
				"ts" : Timestamp(1593478263, 1),
				"t" : NumberLong(2)
			},
			"optimeDate" : ISODate("2020-06-30T00:51:03Z"),
			"syncingTo" : "",
			"syncSourceHost" : "",
			"syncSourceId" : -1,
			"infoMessage" : "",
			"electionTime" : Timestamp(1593419794, 1),
			"electionDate" : ISODate("2020-06-29T08:36:34Z"),
			"configVersion" : 3,
			"self" : true,
			"lastHeartbeatMessage" : ""
		},
		{
			"_id" : 2,
			"name" : "192.168.65.130:27019",
			"health" : 1,
			"state" : 2,
			"stateStr" : "SECONDARY",
			"uptime" : 58377,
			"optime" : {
				"ts" : Timestamp(1593478263, 1),
				"t" : NumberLong(2)
			},
			"optimeDurable" : {
				"ts" : Timestamp(1593478263, 1),
				"t" : NumberLong(2)
			},
			"optimeDate" : ISODate("2020-06-30T00:51:03Z"),
			"optimeDurableDate" : ISODate("2020-06-30T00:51:03Z"),
			"lastHeartbeat" : ISODate("2020-06-30T00:51:11.969Z"),
			"lastHeartbeatRecv" : ISODate("2020-06-30T00:51:11.969Z"),
			"pingMs" : NumberLong(0),
			"lastHeartbeatMessage" : "",
			"syncingTo" : "192.168.65.130:27018",
			"syncSourceHost" : "192.168.65.130:27018",
			"syncSourceId" : 1,
			"infoMessage" : "",
			"configVersion" : 3
		},
		{
			"_id" : 3,
			"name" : "192.168.65.130:27020",
			"health" : 1,
			"state" : 7,
			"stateStr" : "ARBITER",
			"uptime" : 58370,
			"lastHeartbeat" : ISODate("2020-06-30T00:51:12.334Z"),
			"lastHeartbeatRecv" : ISODate("2020-06-30T00:51:12.055Z"),
			"pingMs" : NumberLong(0),
			"lastHeartbeatMessage" : "",
			"syncingTo" : "",
			"syncSourceHost" : "",
			"syncSourceId" : -1,
			"infoMessage" : "",
			"configVersion" : 3
		}
	],
	"ok" : 1,
	"$clusterTime" : {
		"clusterTime" : Timestamp(1593478263, 1),
		"signature" : {
			"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
			"keyId" : NumberLong(0)
		}
	},
	"operationTime" : Timestamp(1593478263, 1)
}

2.手動停止27018（主服務）

ty:PRIMARY> use admin
switched to db admin
ty:PRIMARY> db.shutdownServer()
[mongodb@ty1 ~]$ ps -ef|grep mongo
mongodb   12563      1  1 Jun29 ?        00:11:02 mongod --config /mongodb/27019/mongodb_27019.conf
mongodb   12605      1  0 Jun29 ?        00:07:27 mongod --config /mongodb/27020/mongodb_27020.conf
mongodb   22114  12839  0 08:42 pts/2    00:00:00 mongo --port 27019

 3.連入其他節點

[mongodb@ty1 ~]$ mongo --port 27019

ty:PRIMARY> 

當連入27019 對應的實例時，提示符已經顯示的是 Primary 。

4.檢查複製集狀態

"members" : [
		{
			"_id" : 1,
			"name" : "192.168.65.130:27018",
			"health" : 0,
			"state" : 8,
			"stateStr" : "(not reachable/healthy)",
			"uptime" : 0,
			"optime" : {
				"ts" : Timestamp(0, 0),
				"t" : NumberLong(-1)
			},
			"optimeDurable" : {
				"ts" : Timestamp(0, 0),
				"t" : NumberLong(-1)
			},
			"optimeDate" : ISODate("1970-01-01T00:00:00Z"),
			"optimeDurableDate" : ISODate("1970-01-01T00:00:00Z"),
			"lastHeartbeat" : ISODate("2020-06-30T00:56:30.323Z"),
			"lastHeartbeatRecv" : ISODate("2020-06-30T00:53:02.027Z"),
			"pingMs" : NumberLong(0),
			"lastHeartbeatMessage" : "Error connecting to 192.168.65.130:27018 :: caused by :: Connection refused",
			"syncingTo" : "",
			"syncSourceHost" : "",
			"syncSourceId" : -1,
			"infoMessage" : "",
			"configVersion" : -1
		},
		{
			"_id" : 2,
			"name" : "192.168.65.130:27019",
			"health" : 1,
			"state" : 1,
			"stateStr" : "PRIMARY",
			"uptime" : 58787,
			"optime" : {
				"ts" : Timestamp(1593478582, 1),
				"t" : NumberLong(3)
			},
			"optimeDate" : ISODate("2020-06-30T00:56:22Z"),
			"syncingTo" : "",
			"syncSourceHost" : "",
			"syncSourceId" : -1,
			"infoMessage" : "",
			"electionTime" : Timestamp(1593478382, 1),
			"electionDate" : ISODate("2020-06-30T00:53:02Z"),
			"configVersion" : 3,
			"self" : true,
			"lastHeartbeatMessage" : ""
		},
		{
			"_id" : 3,
			"name" : "192.168.65.130:27020",
			"health" : 1,
			"state" : 7,
			"stateStr" : "ARBITER",
			"uptime" : 58688,
			"lastHeartbeat" : ISODate("2020-06-30T00:56:30.229Z"),
			"lastHeartbeatRecv" : ISODate("2020-06-30T00:56:30.208Z"),
			"pingMs" : NumberLong(0),
			"lastHeartbeatMessage" : "",
			"syncingTo" : "",
			"syncSourceHost" : "",
			"syncSourceId" : -1,
			"infoMessage" : "",
			"configVersion" : 3
		}
	],
	"ok" : 1,
	"$clusterTime" : {
		"clusterTime" : Timestamp(1593478582, 1),
		"signature" : {
			"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
			"keyId" : NumberLong(0)
		}
	},
	"operationTime" : Timestamp(1593478582, 1)
}

可以看到狀態信息中stateStr欄位，主節點的從 primary 變成了 (not reachable/healthy) ， SECONDARY 節點從 SECONDARY 變成了 primary，說明完成自動切換任務

5.寫入測試

ty:PRIMARY> db.ty.insert({age:1000})
WriteResult({ "nInserted" : 1 })
ty:PRIMARY> db.ty.find()
{ "_id" : ObjectId("5ef9a99662e0d2208ccde0cc"), "ty" : 11 }
{ "_id" : ObjectId("5efa8adc3b55e73f44c6539e"), "age" : 100 }
{ "_id" : ObjectId("5efa8ed6d009f8bab0438011"), "age" : 1000 }

讀寫正常

6.故障節點重新啓動

[mongodb@ty1 ~]$ mongod --config /mongodb/27018/mongodb_27018.conf 
about to fork child process, waiting until server is ready for connections.
forked process: 22362
child process started successfully, parent exiting
[mongodb@ty1 ~]$ mongo --port 27018
則該節點角色將變爲secondary，且自動複製最新的數據到本節點
ty:SECONDARY> db.getMongo().setSlaveOk()
ty:SECONDARY> db.ty.find();
{ "_id" : ObjectId("5ef9a99662e0d2208ccde0cc"), "ty" : 11 }
{ "_id" : ObjectId("5efa8adc3b55e73f44c6539e"), "age" : 100 }
{ "_id" : ObjectId("5efa8ed6d009f8bab0438011"), "age" : 1000 }

添加節點

1.配置新實例
2.添加新實例
    a.連接主節點
    b.添加節點
    rs.add("192.168.65.130:27021")
3.查看配置
4.數據驗證
        

刪除節點

rs.remove("192.168.65.130:27021")