接上一篇博文整理—》

6. MongoDB复制集RS（ReplicationSet）

6.1 基本原理

基本构成是1主2从的结构，自带互相监控投票机制（Raft（MongoDB）  Paxos（mysql MGR 用的是变种））
如果发生主库宕机，复制集内部会进行投票选举，选择一个新的主库替代原有主库对外提供服务。同时复制集会自动通知
客户端程序，主库已经发生切换了。应用就会连接到新的主库。

在这里插入图片描述

6.2 Replication Set配置过程详解

6.2.1 规划

三个以上的mongodb节点（或多实例）

6.2.2 环境准备

1. 多个端口：

28017、28018、28019、28020

2. 多套目录：

su - mongod 
mkdir -p /mongodb/28017/conf /mongodb/28017/data /mongodb/28017/log
mkdir -p /mongodb/28018/conf /mongodb/28018/data /mongodb/28018/log
mkdir -p /mongodb/28019/conf /mongodb/28019/data /mongodb/28019/log
mkdir -p /mongodb/28020/conf /mongodb/28020/data /mongodb/28020/log

3. 多套配置文件

/mongodb/28017/conf/mongod.conf
/mongodb/28018/conf/mongod.conf
/mongodb/28019/conf/mongod.conf
/mongodb/28020/conf/mongod.conf

4. 配置文件内容

cat > /mongodb/28017/conf/mongod.conf <<EOF
systemLog:
  destination: file
  path: /mongodb/28017/log/mongodb.log
  logAppend: true
storage:
  journal:
    enabled: true
  dbPath: /mongodb/28017/data
  directoryPerDB: true
  #engine: wiredTiger 引擎
  wiredTiger:
    engineConfig:
      cacheSizeGB: 1		#缓存大小
      directoryForIndexes: true
    collectionConfig:
      blockCompressor: zlib
    indexConfig:
      prefixCompression: true
processManagement:
  fork: true
net:
  bindIp: 10.0.0.51,127.0.0.1
  port: 28017
replication:
  oplogSizeMB: 2048		#日志最大容量
  replSetName: my_repl
EOF
        

\cp  /mongodb/28017/conf/mongod.conf  /mongodb/28018/conf/
\cp  /mongodb/28017/conf/mongod.conf  /mongodb/28019/conf/
\cp  /mongodb/28017/conf/mongod.conf  /mongodb/28020/conf/

sed 's#28017#28018#g' /mongodb/28018/conf/mongod.conf -i
sed 's#28017#28019#g' /mongodb/28019/conf/mongod.conf -i
sed 's#28017#28020#g' /mongodb/28020/conf/mongod.conf -i

5. 启动多个实例备用

[mongod@db01 ~]$ mongod -f /mongodb/28017/conf/mongod.conf
about to fork child process, waiting until server is ready for connections.
forked process: 3034
child process started successfully, parent exiting
[mongod@db01 ~]$ mongod -f /mongodb/28018/conf/mongod.conf
about to fork child process, waiting until server is ready for connections.
forked process: 3063
child process started successfully, parent exiting
[mongod@db01 ~]$ mongod -f /mongodb/28019/conf/mongod.conf
about to fork child process, waiting until server is ready for connections.
forked process: 3092
child process started successfully, parent exiting
[mongod@db01 ~]$ mongod -f /mongodb/28020/conf/mongod.conf
about to fork child process, waiting until server is ready for connections.
forked process: 3121
child process started successfully, parent exiting

[mongod@db01 ~]$ netstat -lnp|grep 280
(Not all processes could be identified, non-owned process info
 will not be shown, you would have to be root to see it all.)
tcp        0      0 127.0.0.1:28017         0.0.0.0:*               LISTEN      3034/mongod         
tcp        0      0 10.0.0.51:28017         0.0.0.0:*               LISTEN      3034/mongod         
tcp        0      0 127.0.0.1:28018         0.0.0.0:*               LISTEN      3063/mongod         
tcp        0      0 10.0.0.51:28018         0.0.0.0:*               LISTEN      3063/mongod         
tcp        0      0 127.0.0.1:28019         0.0.0.0:*               LISTEN      3092/mongod         
tcp        0      0 10.0.0.51:28019         0.0.0.0:*               LISTEN      3092/mongod         
tcp        0      0 127.0.0.1:28020         0.0.0.0:*               LISTEN      3121/mongod         
tcp        0      0 10.0.0.51:28020         0.0.0.0:*               LISTEN      3121/mongod         
unix  2      [ ACC ]     STREAM     LISTENING     42006    3034/mongod          /tmp/mongodb-28017.sock
unix  2      [ ACC ]     STREAM     LISTENING     42017    3063/mongod          /tmp/mongodb-28018.sock
unix  2      [ ACC ]     STREAM     LISTENING     42031    3092/mongod          /tmp/mongodb-28019.sock
unix  2      [ ACC ]     STREAM     LISTENING     42048    3121/mongod          /tmp/mongodb-28020.sock

6.3 配置普通复制集：

1主2从，从库普通从库
[mongod@db01 ~]$ mongo --port 28017 admin
> config = {_id: 'my_repl', members: [
...                           {_id: 0, host: '10.0.0.51:28017'},
...                           {_id: 1, host: '10.0.0.51:28018'},
...                           {_id: 2, host: '10.0.0.51:28019'}]
...           } 
{
	"_id" : "my_repl",
	"members" : [
		{
			"_id" : 0,
			"host" : "10.0.0.51:28017"
		},
		{
			"_id" : 1,
			"host" : "10.0.0.51:28018"
		},
		{
			"_id" : 2,
			"host" : "10.0.0.51:28019"
		}
	]
}
> rs.initiate(config) 
{
	"ok" : 1,
	"operationTime" : Timestamp(1578626170, 1),
	"$clusterTime" : {
		"clusterTime" : Timestamp(1578626170, 1),
		"signature" : {
			"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
			"keyId" : NumberLong(0)
		}
	}
}
my_repl:SECONDARY> 
my_repl:PRIMARY> 
my_repl:PRIMARY> 
my_repl:PRIMARY> 


查询复制集状态
my_repl:PRIMARY> rs.status();
{
	"set" : "my_repl",
	"date" : ISODate("2020-01-10T03:17:27.739Z"),
	"myState" : 1,
	"term" : NumberLong(1),
	"syncingTo" : "",
	"syncSourceHost" : "",
	"syncSourceId" : -1,
	"heartbeatIntervalMillis" : NumberLong(2000),
	"optimes" : {
		"lastCommittedOpTime" : {
			"ts" : Timestamp(1578626243, 1),
			"t" : NumberLong(1)
		},
		"readConcernMajorityOpTime" : {
			"ts" : Timestamp(1578626243, 1),
			"t" : NumberLong(1)
		},
		"appliedOpTime" : {
			"ts" : Timestamp(1578626243, 1),
			"t" : NumberLong(1)
		},
		"durableOpTime" : {
			"ts" : Timestamp(1578626243, 1),
			"t" : NumberLong(1)
		}
	},
	"members" : [
		{
			"_id" : 0,
			"name" : "10.0.0.51:28017",
			"health" : 1,
			"state" : 1,
			"stateStr" : "PRIMARY",
			"uptime" : 174,
			"optime" : {
				"ts" : Timestamp(1578626243, 1),
				"t" : NumberLong(1)
			},
			"optimeDate" : ISODate("2020-01-10T03:17:23Z"),
			"syncingTo" : "",
			"syncSourceHost" : "",
			"syncSourceId" : -1,
			"infoMessage" : "could not find member to sync from",
			"electionTime" : Timestamp(1578626182, 1),
			"electionDate" : ISODate("2020-01-10T03:16:22Z"),
			"configVersion" : 1,
			"self" : true,
			"lastHeartbeatMessage" : ""
		},
		{
			"_id" : 1,
			"name" : "10.0.0.51:28018",
			"health" : 1,
			"state" : 2,
			"stateStr" : "SECONDARY",
			"uptime" : 77,
			"optime" : {
				"ts" : Timestamp(1578626243, 1),
				"t" : NumberLong(1)
			},
			"optimeDurable" : {
				"ts" : Timestamp(1578626243, 1),
				"t" : NumberLong(1)
			},
			"optimeDate" : ISODate("2020-01-10T03:17:23Z"),
			"optimeDurableDate" : ISODate("2020-01-10T03:17:23Z"),
			"lastHeartbeat" : ISODate("2020-01-10T03:17:26.070Z"),
			"lastHeartbeatRecv" : ISODate("2020-01-10T03:17:26.844Z"),
			"pingMs" : NumberLong(0),
			"lastHeartbeatMessage" : "",
			"syncingTo" : "10.0.0.51:28017",
			"syncSourceHost" : "10.0.0.51:28017",
			"syncSourceId" : 0,
			"infoMessage" : "",
			"configVersion" : 1
		},
		{
			"_id" : 2,
			"name" : "10.0.0.51:28019",
			"health" : 1,
			"state" : 2,
			"stateStr" : "SECONDARY",
			"uptime" : 77,
			"optime" : {
				"ts" : Timestamp(1578626243, 1),
				"t" : NumberLong(1)
			},
			"optimeDurable" : {
				"ts" : Timestamp(1578626243, 1),
				"t" : NumberLong(1)
			},
			"optimeDate" : ISODate("2020-01-10T03:17:23Z"),
			"optimeDurableDate" : ISODate("2020-01-10T03:17:23Z"),
			"lastHeartbeat" : ISODate("2020-01-10T03:17:26.070Z"),
			"lastHeartbeatRecv" : ISODate("2020-01-10T03:17:26.836Z"),
			"pingMs" : NumberLong(0),
			"lastHeartbeatMessage" : "",
			"syncingTo" : "10.0.0.51:28017",
			"syncSourceHost" : "10.0.0.51:28017",
			"syncSourceId" : 0,
			"infoMessage" : "",
			"configVersion" : 1
		}
	],
	"ok" : 1,
	"operationTime" : Timestamp(1578626243, 1),
	"$clusterTime" : {
		"clusterTime" : Timestamp(1578626243, 1),
		"signature" : {
			"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
			"keyId" : NumberLong(0)
		}
	}
}
my_repl:PRIMARY>

6.4 1主1从1个arbiter

mongo -port 28017 admin
config = {_id: 'my_repl', members: [
                          {_id: 0, host: '10.0.0.51:28017'},
                          {_id: 1, host: '10.0.0.51:28018'},
                          {_id: 2, host: '10.0.0.51:28019',"arbiterOnly":true}]
          }      
                    
rs.initiate(config)

6.5 复制集管理操作

6.5.1 查看复制集状态

1. rs.status();    //查看整体复制集状态
2. rs.isMaster(); // 查看当前是否是主节点
3. rs.conf();   //查看复制集配置信息
my_repl:PRIMARY> rs.conf()
{
	"_id" : "my_repl",
	"version" : 1,
	"protocolVersion" : NumberLong(1),
	"members" : [
		{
			"_id" : 0,
			"host" : "10.0.0.51:28017",
			"arbiterOnly" : false,
			"buildIndexes" : true,
			"hidden" : false,
			"priority" : 1,
			"tags" : {
				
			},
			"slaveDelay" : NumberLong(0),	#类似于延时从库
			"votes" : 1
		},
		{
			"_id" : 1,
			"host" : "10.0.0.51:28018",
			"arbiterOnly" : false,
			"buildIndexes" : true,
			"hidden" : false,
			"priority" : 1,
			"tags" : {
				
			},
			"slaveDelay" : NumberLong(0),
			"votes" : 1
		},
		{
			"_id" : 2,
			"host" : "10.0.0.51:28019",
			"arbiterOnly" : false,
			"buildIndexes" : true,
			"hidden" : false,
			"priority" : 1,
			"tags" : {
				
			},
			"slaveDelay" : NumberLong(0),
			"votes" : 1
		}
	],
	"settings" : {
		"chainingAllowed" : true,
		"heartbeatIntervalMillis" : 2000,
		"heartbeatTimeoutSecs" : 10,
		"electionTimeoutMillis" : 10000,
		"catchUpTimeoutMillis" : -1,
		"catchUpTakeoverDelayMillis" : 30000,
		"getLastErrorModes" : {
			
		},
		"getLastErrorDefaults" : {
			"w" : 1,
			"wtimeout" : 0
		},
		"replicaSetId" : ObjectId("5e17ec7a5506d8f4ad899583")
	}
}

6.5.2 添加删除节点

rs.remove("ip:port"); // 删除一个节点
rs.add("ip:port"); // 新增从节点
rs.addArb("ip:port"); // 新增仲裁节点

例子：
添加 arbiter节点
1、连接到主节点
[mongod@db01 ~]$ mongo --port 28018 admin
    
2、添加仲裁节点
my_repl:PRIMARY> rs.addArb("10.0.0.51:28020")
{
	"ok" : 1,
	"operationTime" : Timestamp(1578626917, 1),
	"$clusterTime" : {
		"clusterTime" : Timestamp(1578626917, 1),
		"signature" : {
			"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
			"keyId" : NumberLong(0)
		}
	}
}

    
3、查看节点状态
my_repl:PRIMARY> rs.isMaster()
{
	"hosts" : [
		"10.0.0.51:28017",
		"10.0.0.51:28018",
		"10.0.0.51:28019"
	],
	"arbiters" : [
		"10.0.0.51:28020"
	],
	"setName" : "my_repl",
	"setVersion" : 2,
	"ismaster" : true,
	"secondary" : false,
	"primary" : "10.0.0.51:28017",
	"me" : "10.0.0.51:28017",
	"electionId" : ObjectId("7fffffff0000000000000001"),
	"lastWrite" : {
		"opTime" : {
			"ts" : Timestamp(1578626917, 1),
			"t" : NumberLong(1)
		},
		"lastWriteDate" : ISODate("2020-01-10T03:28:37Z"),
		"majorityOpTime" : {
			"ts" : Timestamp(1578626917, 1),
			"t" : NumberLong(1)
		},
		"majorityWriteDate" : ISODate("2020-01-10T03:28:37Z")
	},
	"maxBsonObjectSize" : 16777216,
	"maxMessageSizeBytes" : 48000000,
	"maxWriteBatchSize" : 100000,
	"localTime" : ISODate("2020-01-10T03:28:46.949Z"),
	"logicalSessionTimeoutMinutes" : 30,
	"minWireVersion" : 0,
	"maxWireVersion" : 6,
	"readOnly" : false,
	"ok" : 1,
	"operationTime" : Timestamp(1578626917, 1),
	"$clusterTime" : {
		"clusterTime" : Timestamp(1578626917, 1),
		"signature" : {
			"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
			"keyId" : NumberLong(0)
		}
	}
}

rs.remove("ip:port"); // 删除一个节点
例子：
my_repl:PRIMARY> rs.remove("10.0.0.51:28019");
{
	"ok" : 1,
	"operationTime" : Timestamp(1578627065, 1),
	"$clusterTime" : {
		"clusterTime" : Timestamp(1578627065, 1),
		"signature" : {
			"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
			"keyId" : NumberLong(0)
		}
	}
}

my_repl:PRIMARY> rs.isMaster() 	#查询
{
	"hosts" : [
		"10.0.0.51:28017",
		"10.0.0.51:28018"
	],

    
rs.add("ip:port"); // 新增从节点
例子：
my_repl:PRIMARY> rs.add("10.0.0.51:28019")
{ "ok" : 1 }
my_repl:PRIMARY> rs.isMaster()

6.5.3 特殊从节点

1. 介绍：

arbiter节点：主要负责选主过程中的投票，但是不存储任何数据，也不提供任何服务
hidden节点：隐藏节点，不参与选主，也不对外提供服务。
delay节点：延时节点，数据落后于主库一段时间，因为数据是延时的，也不应该提供服务或参与选主，所以通常会配合hidden（隐藏）
一般情况下会将delay+hidden一起配置使用

2. 配置延时节点（一般延时节点也配置成hidden）

cfg=rs.conf() 
cfg.members[3].priority=0		#修改3号节点的值
cfg.members[3].hidden=true		#隐藏
cfg.members[3].slaveDelay=120	#延时
my_repl:PRIMARY> rs.reconfig(cfg) 
{
	"ok" : 1,
	"operationTime" : Timestamp(1578628124, 1),
	"$clusterTime" : {
		"clusterTime" : Timestamp(1578628124, 1),
		"signature" : {
			"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),
			"keyId" : NumberLong(0)
		}
	}
}

my_repl:PRIMARY> rs.conf();  #查看修改后的信息
		{
			"_id" : 4,
			"host" : "10.0.0.51:28019",
			"arbiterOnly" : false,
			"buildIndexes" : true,
			"hidden" : true,
			"priority" : 0,
			"tags" : {
				
			},
			"slaveDelay" : NumberLong(120),
			"votes" : 1
		}

注意：节点号必须仔细查看，是按照顺序进行排列的，需要修改哪个按顺序数即可

取消以上配置
cfg=rs.conf() 
cfg.members[2].priority=1
cfg.members[2].hidden=false
cfg.members[2].slaveDelay=0
rs.reconfig(cfg)    
配置成功后，通过以下命令查询配置后的属性
rs.conf();

6.5.4 副本集其他操作命令

查看副本集的配置信息
admin> rs.conf()
查看副本集各成员的状态
admin> rs.status()
++++++++++++++++++++++++++++++++++++++++++++++++
--副本集角色切换（不要人为随便操作）
admin> rs.stepDown()
注：
admin> rs.freeze(300) //锁定从，使其不会转变成主库
freeze()和stepDown单位都是秒。
+++++++++++++++++++++++++++++++++++++++++++++
设置副本节点可读：在副本节点执行
admin> rs.slaveOk()
eg：
admin> use app
switched to db app
app> db.createCollection('a')
{ "ok" : 0, "errmsg" : "not master", "code" : 10107 }

查看副本节点（监控主从延时）
admin> rs.printSlaveReplicationInfo()
source: 192.168.1.22:27017
    syncedTo: Thu May 26 2016 10:28:56 GMT+0800 (CST)
    0 secs (0 hrs) behind the primary

寻花之梦~~

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146. MongoDB复制集RS（ReplicationSet）

文章目录

接上一篇博文整理—》

6. MongoDB复制集RS（ReplicationSet）

6.1 基本原理

6.2 Replication Set配置过程详解

6.2.1 规划

6.2.2 环境准备

1. 多个端口：

2. 多套目录：

3. 多套配置文件

4. 配置文件内容

5. 启动多个实例备用

6.3 配置普通复制集：

6.4 1主1从1个arbiter

6.5 复制集管理操作

6.5.1 查看复制集状态

6.5.2 添加删除节点

6.5.3 特殊从节点

1. 介绍：

2. 配置延时节点（一般延时节点也配置成hidden）

6.5.4 副本集其他操作命令

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