21.33 mongodb副本集介紹

時間  2019-11-05
標籤 21.33 mongodb 副本 介紹 欄目 MongoDB 简体版
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21.33 mongodb副本集介紹

MongoDB副本集：mysql

早期版本使用master-slave，一主一從和MySQL相似，但slave在此架構中爲只讀，當主庫宕機後，從庫不能自動切換爲主
目前已經淘汰master-slave模式，改成副本集，這種模式下有一個主(primary)，和多個從(secondary)，只讀。支持給它們設置權重，當主宕掉後，權重最高的從切換爲主
在此架構中還能夠創建一個仲裁(arbiter)的角色，它只負責裁決，而不存儲數據
再此架構中讀寫數據都是在主上，要想實現負載均衡的目的須要手動指定讀庫的目標serverlinux

副本集架構圖：
mark
mark
副本集primary宕機示意圖： marksql

21.34 mongodb副本集搭建

三臺機器： 192.168.133.130(primary) 192.168.133.132(secondary) 192.168.133.133(secondary)
編輯三臺機器的配置文件，更改或增長：
replication://把此行前面的#刪除
##oplog大小
oplogSizeMB: 20//前面有兩個空格
##複製集名稱
replSetName: aminglinux//前面有兩個空格
分別重啓三臺機器服務mongodb

鏈接主，在主上運行命令mongo
>use admin
>config={_id:"aminglinux",members:[{_id:0,host:"192.168.133.130:27017"},{_id:1,host:"192.168.133.132:27017"},{_id:2,host:"192.168.133.133:27017"}]}
>rs.initiate(config)
 rs.status() //查看狀態
 若是兩個從上的狀態爲"stateStr" : "STARTUP", 則須要進行以下操做
> var config={_id:"aminglinux",members:[{_id:0,host:"192.168.133.130:27017"},{_id:1,host:"192.168.133.132:27017"},{_id:2,host:"192.168.133.133:27017"}]}
 >rs.reconfig(config)
 此時再次查看rs.status()會發現從的狀態變爲SECONDARY
> use admin
switched to db admin
> config={_id:"aminglinux",members:[{_id:0,host:"192.168.60.11:27017"},{_id:1,host:"192.168.60.12:27017"},{_id:2,host:"192.168.60.13:27017"}]}
{
	"_id" : "aminglinux",
	"members" : [
		{
			"_id" : 0,
			"host" : "192.168.60.11:27017"
		},
		{
			"_id" : 1,
			"host" : "192.168.60.12:27017"
		},
		{
			"_id" : 2,
			"host" : "192.168.60.13:27017"
		}
	]
}
> 
> rs.initiate(config)
{ "ok" : 1 }  ##是1 就對了；
aminglinux:PRIMARY> rs.status()    ##查看狀態；
{
	"set" : "aminglinux",
	"date" : ISODate("2017-10-19T19:41:16.726Z"),
	"myState" : 1,
	"term" : NumberLong(1),
	"heartbeatIntervalMillis" : NumberLong(2000),
	"optimes" : {
		"lastCommittedOpTime" : {
			"ts" : Timestamp(1508442074, 1),
			"t" : NumberLong(1)
		},
		"appliedOpTime" : {
			"ts" : Timestamp(1508442074, 1),
			"t" : NumberLong(1)
		},
		"durableOpTime" : {
			"ts" : Timestamp(1508442074, 1),
			"t" : NumberLong(1)
		}
	},
	"members" : [
		{
			"_id" : 0,
			"name" : "192.168.60.11:27017",
			"health" : 1,
			"state" : 1,
			"stateStr" : "PRIMARY",
			"uptime" : 2851,
			"optime" : {
				"ts" : Timestamp(1508442074, 1),
				"t" : NumberLong(1)
			},
			"optimeDate" : ISODate("2017-10-19T19:41:14Z"),
			"electionTime" : Timestamp(1508439306, 1),
			"electionDate" : ISODate("2017-10-19T18:55:06Z"),
			"configVersion" : 6,
			"self" : true
		},
		{
			"_id" : 2,
			"name" : "192.168.60.12:27017",
			"health" : 1,
			"state" : 2,
			"stateStr" : "SECONDARY",
			"uptime" : 75,
			"optime" : {
				"ts" : Timestamp(1508442074, 1),
				"t" : NumberLong(1)
			},
			"optimeDurable" : {
				"ts" : Timestamp(1508442074, 1),
				"t" : NumberLong(1)
			},
			"optimeDate" : ISODate("2017-10-19T19:41:14Z"),
			"optimeDurableDate" : ISODate("2017-10-19T19:41:14Z"),
			"lastHeartbeat" : ISODate("2017-10-19T19:41:16.633Z"),
			"lastHeartbeatRecv" : ISODate("2017-10-19T19:41:14.635Z"),
			"pingMs" : NumberLong(0),
			"syncingTo" : "192.168.60.11:27017",
			"configVersion" : 6
		},
		{
			"_id" : 3,
			"name" : "192.168.60.13:27017",
			"health" : 1,
			"state" : 2,
			"stateStr" : "SECONDARY",
			"uptime" : 0,
			"optime" : {
				"ts" : Timestamp(1508442074, 1),
				"t" : NumberLong(1)
			},
			"optimeDurable" : {
				"ts" : Timestamp(1508442074, 1),
				"t" : NumberLong(1)
			},
			"optimeDate" : ISODate("2017-10-19T19:41:14Z"),
			"optimeDurableDate" : ISODate("2017-10-19T19:41:14Z"),
			"lastHeartbeat" : ISODate("2017-10-19T19:41:16.630Z"),
			"lastHeartbeatRecv" : ISODate("2017-10-19T19:41:16.645Z"),
			"pingMs" : NumberLong(0),
			"syncingTo" : "192.168.60.11:27017",
			"configVersion" : 6
		}
	],
	"ok" : 1
}

21.35 mongodb副本集測試

MongoDB副本集測試：shell

主上建庫，建集合
 >use mydb
 >db.acc.insert({AccountID:1,UserName:"123",password:"123456"})
 >show dbs
 從上查看
 >show dbs   
 若出現錯誤Error: listDatabases failed:{ "note" : "from execCommand", "ok" : 0, "errmsg" : "not master" }，須要執行
 >rs.slaveok()
aminglinux:PRIMARY> use mysql   ##在從上面建立mysql
switched to db mysql
aminglinux:PRIMARY> db.acc.insert({AccountID:1,UserName:"123",password:"123456"})  
##建立一個集合acc，並插入數據
WriteResult({ "nInserted" : 1 })
aminglinux:PRIMARY> show dbs;
db1    0.000GB
local  0.000GB
mysql  0.000GB
##接下來咱們等了60.12secondary查看同步
aminglinux:SECONDARY> show dbs
2017-10-19T20:47:39.795+0800 E QUERY    [thread1] Error: listDatabases failed:{
	"ok" : 0,
	"errmsg" : "not master and slaveOk=false",  ##這裏沒法查看
	"code" : 13435,
	"codeName" : "NotMasterNoSlaveOk"
} :
_getErrorWithCode@src/mongo/shell/utils.js:25:13
Mongo.prototype.getDBs@src/mongo/shell/mongo.js:62:1
shellHelper.show@src/mongo/shell/utils.js:769:19
shellHelper@src/mongo/shell/utils.js:659:15
@(shellhelp2):1:1
aminglinux:SECONDARY> rs.slaveOk()  ##執行這個，讓slave能夠查看；
aminglinux:SECONDARY> show dbs
db1    0.000GB
local  0.000GB
mysql  0.000GB

副本集更改權重模擬主宕機：服務器

默認三臺機器權重都爲1，若是任何一個權重設置爲比其餘的高，則該臺機器立刻切換爲primary角色，因此咱們預設三臺機器的權重分別爲：130:3,132:2,133:1
 在主上執行
 cfg = rs.conf()
 cfg.members[0].priority = 3
 cfg.members[1].priority = 2
 cfg.members[2].priority = 1
 rs.reconfig(cfg)
 這樣的話，第二個節點將會成爲候選主節點。
 主上執行 iptables -I INPUT -p tcp --dport 27017 -j DROP
aminglinux:PRIMARY> rs.config()    ##查看配置，priority是其權重
{
	"_id" : "aminglinux",
	"version" : 6,
	"protocolVersion" : NumberLong(1),
	"members" : [
		{
			"_id" : 0,
			"host" : "192.168.60.11:27017",
			"arbiterOnly" : false,
			"buildIndexes" : true,
			"hidden" : false,
			"priority" : 1,
			"tags" : {
				
			},
			"slaveDelay" : NumberLong(0),
			"votes" : 1
		},
		{
			"_id" : 2,
			"host" : "192.168.60.12:27017",
			"arbiterOnly" : false,
			"buildIndexes" : true,
			"hidden" : false,
			"priority" : 1,
			"tags" : {
				
			},
			"slaveDelay" : NumberLong(0),
			"votes" : 1
		},
		{
			"_id" : 3,
			"host" : "192.168.60.13:27017",
			"arbiterOnly" : false,
			"buildIndexes" : true,
			"hidden" : false,
			"priority" : 1,
			"tags" : {
				
			},
			"slaveDelay" : NumberLong(0),
			"votes" : 1
		}
	],
	"settings" : {
		"chainingAllowed" : true,
		"heartbeatIntervalMillis" : 2000,
		"heartbeatTimeoutSecs" : 10,
		"electionTimeoutMillis" : 10000,
		"catchUpTimeoutMillis" : 60000,
		"getLastErrorModes" : {
			
		},
		"getLastErrorDefaults" : {
			"w" : 1,
			"wtimeout" : 0
		},
		"replicaSetId" : ObjectId("59e8f4ffee48611ad04ee633")
	}
}
[root@Dasoncheng ~]# iptables -I INPUT -p tcp --dport 27017 -j DROP
##在primary上面執行這條命令，drop掉27017端口的通訊；在其餘副本集查看狀態
aminglinux:PRIMARY> rs.status()  ##60.12已經成爲primary了；
{
	"set" : "aminglinux",
	"date" : ISODate("2017-10-19T13:04:55.021Z"),
	"myState" : 1,
	"term" : NumberLong(2),
	"heartbeatIntervalMillis" : NumberLong(2000),
	"optimes" : {
		"lastCommittedOpTime" : {
			"ts" : Timestamp(1508443618, 5),
			"t" : NumberLong(2)
		},
		"appliedOpTime" : {
			"ts" : Timestamp(1508443618, 5),
			"t" : NumberLong(2)
		},
		"durableOpTime" : {
			"ts" : Timestamp(1508443618, 5),
			"t" : NumberLong(2)
		}
	},
	"members" : [
		{
			"_id" : 0,
			"name" : "192.168.60.11:27017",
			"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("2017-10-19T13:04:50.892Z"),
			"lastHeartbeatRecv" : ISODate("2017-10-19T13:04:54.910Z"),
			"pingMs" : NumberLong(1),
			"lastHeartbeatMessage" : "Couldn't get a connection within the time limit",
			"configVersion" : -1
		},
		{
			"_id" : 2,
			"name" : "192.168.60.12:27017",
			"health" : 1,
			"state" : 1,
			"stateStr" : "PRIMARY",
			"uptime" : 6295,
			"optime" : {
				"ts" : Timestamp(1508443618, 5),
				"t" : NumberLong(2)
			},
			"optimeDate" : ISODate("2017-10-19T20:06:58Z"),
			"electionTime" : Timestamp(1508443618, 2),
			"electionDate" : ISODate("2017-10-19T20:06:58Z"),
			"configVersion" : 6,
			"self" : true
		},
		{
			"_id" : 3,
			"name" : "192.168.60.13:27017",
			"health" : 1,
			"state" : 2,
			"stateStr" : "SECONDARY",
			"uptime" : 1591,
			"optime" : {
				"ts" : Timestamp(1508443618, 1),
				"t" : NumberLong(1)
			},
			"optimeDurable" : {
				"ts" : Timestamp(1508443618, 1),
				"t" : NumberLong(1)
			},
			"optimeDate" : ISODate("2017-10-19T20:06:58Z"),
			"optimeDurableDate" : ISODate("2017-10-19T20:06:58Z"),
			"lastHeartbeat" : ISODate("2017-10-19T13:04:53.973Z"),
			"lastHeartbeatRecv" : ISODate("2017-10-19T13:04:53.173Z"),
			"pingMs" : NumberLong(1),
			"syncingTo" : "192.168.60.11:27017",
			"configVersion" : 6
		}
	],
	"ok" : 1
}
##在這裏呢，由於權重都爲1 全部選擇primary具備隨機性；咱們這裏設置權重來指定
aminglinux:PRIMARY> cfg=rs.conf()    ##設置一個變量，下面爲設置權重
aminglinux:PRIMARY> cfg.members[0].priority = 3
3
aminglinux:PRIMARY> cfg.members[1].priority = 2
2
aminglinux:PRIMARY> cfg.members[2].priority = 1
1
aminglinux:PRIMARY> rs.reconfig(cfg)    ##從新加載配置
{ "ok" : 1 }
2017-10-19T21:10:12.635+0800 I NETWORK  [thread1] trying reconnect to 127.0.0.1:27017 (127.0.0.1) failed
2017-10-19T21:10:12.638+0800 I NETWORK  [thread1] reconnect 127.0.0.1:27017 (127.0.0.1) ok
aminglinux:SECONDARY> rs.config()  ##咱們能夠看到，60.12已經變成secondary了；
{
	"_id" : "aminglinux",
	"version" : 7,
	"protocolVersion" : NumberLong(1),
	"members" : [
		{
			"_id" : 0,
			"host" : "192.168.60.11:27017",
			"arbiterOnly" : false,
			"buildIndexes" : true,
			"hidden" : false,
			"priority" : 3,
			"tags" : {
				
			},
			"slaveDelay" : NumberLong(0),
			"votes" : 1
		},
		{
			"_id" : 2,
			"host" : "192.168.60.12:27017",
			"arbiterOnly" : false,
			"buildIndexes" : true,
			"hidden" : false,
			"priority" : 2,
			"tags" : {
				
			},
			"slaveDelay" : NumberLong(0),
			"votes" : 1
		},
		{
			"_id" : 3,
			"host" : "192.168.60.13:27017",
			"arbiterOnly" : false,
			"buildIndexes" : true,
			"hidden" : false,
			"priority" : 1,
			"tags" : {
				
			},
			"slaveDelay" : NumberLong(0),
			"votes" : 1
		}
	],
	"settings" : {
		"chainingAllowed" : true,
		"heartbeatIntervalMillis" : 2000,
		"heartbeatTimeoutSecs" : 10,
		"electionTimeoutMillis" : 10000,
		"catchUpTimeoutMillis" : 60000,
		"getLastErrorModes" : {
			
		},
		"getLastErrorDefaults" : {
			"w" : 1,
			"wtimeout" : 0
		},
		"replicaSetId" : ObjectId("59e8f4ffee48611ad04ee633")
	}
}

小提示：這是副本集的操做； rs.slaveOk();--sencondary機器受權查詢
rs.isMaster()--查看副本集狀態
rs.status()--查看副本集狀態
rs.remove("localhost:20001");--刪除節點 在主服務器執行
rs.add("localhost:20001");--增長節點
rs.initiate(config_rs1);--Initializes a new replica set.
rs.reconfig(config_rs1);--Re-configures a replica set by applying a new replica set configuration object.
rs.的命令官網
http://docs.mongodb.org/manual/reference/method/js-replication/
Replica Set官網說明：
http://docs.mongodb.org/manual/core/replica-set-architecture-three-members/架構

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