当前位置： 首页 > news >正文

手机网站 触屏/百度推广二级代理商

news 2025/6/30 0:44:10
手机网站 触屏,百度推广二级代理商,合肥网站建设-中国互联,重庆装修设计公司排名本文主要介绍了Linux环境下mongoDB副本集模式的搭建（一主一从一仲裁），具体包括了搭建步骤、主从切换、高可用测试等。 架构图 环境 Ubuntu 5.4.0-6ubuntu1~16.04.12mongodb-linux-x86_64-ubuntu1604-4.2.8.tgz 步骤 创建主节点 建立存放数…

本文主要介绍了Linux环境下mongoDB副本集模式的搭建（一主一从一仲裁），具体包括了搭建步骤、主从切换、高可用测试等。

架构图

一主一从一仲裁

环境

  • Ubuntu 5.4.0-6ubuntu1~16.04.12
  • mongodb-linux-x86_64-ubuntu1604-4.2.8.tgz

步骤

创建主节点

  1. 建立存放数据和日志的目录
# 主节点
mkdir -p /mongodb/replica_sets/rs_27017/log
mkdir -p /mongodb/replica_sets/rs_27017/data/db
  1. 或修改配置文件
vim /mongodb/replica_sets/rs_27017/mongod.conf

systemLog:#MongoDB发送所有日志输出的目标指定为文件destination: file#mongod或mongos应向其发送所有诊断日志记录信息的日志文件的路径path: "/mongodb/replica_sets/rs_27017/log/mongod.log"#当mongos或mongod实例重新启动时，mongos或mongod会将新条目附加到现有日志文件的末尾logAppend: true
storage:#mongod实例存储其数据的目录。storage.dbPath设置仅适用于mongoddbPath: "/mongodb/replica_sets/rs_27017/data/db"journal:#启用或禁用持久性日志以确保数据文件保持有效和可恢复。    enabled: true
processManagement:  #启用在后台运行mongos或mongod进程的守护进程模式。fork: true  #指定用于保存mongos或mongod进程的进程ID的文件位置，其中mongos或mongod将写入其PID  pidFilePath: "/mongodb/replica_sets/rs_27017/log/mongod.pid"
net:  #服务实例绑定所有IP，有副作用，副本集初始化的时候，节点名字会自动设置为本地域名，而不是ip  #bindIpAll: true  #服务实例绑定的IP  bindIp: localhost,192.168.30.129 #bindIp  #绑定的端口  port: 27017
replication:  #副本集的名称  replSetName: kwz_rs
  1. 启动节点服务：
    /usr/local/mongodb/bin/mongod -f /mongodb/replica_sets/rs_27017/mongod.conf
    在这里插入图片描述
    此处有一个错误：Error parsing YAML config file: yaml-cpp: error at line 2, column 13: illegal map value，涉及到yml格式空格问题，参考这篇文章解决

创建副本级节点

  1. 建立存放数据和日志的目录
# 主节点
mkdir -p /mongodb/replica_sets/rs_27018/log
mkdir -p /mongodb/replica_sets/rs_27018/data/db
  1. 或修改配置文件
vim /mongodb/replica_sets/rs_27018/mongod.conf

systemLog:#MongoDB发送所有日志输出的目标指定为文件destination: file#mongod或mongos应向其发送所有诊断日志记录信息的日志文件的路径path: "/mongodb/replica_sets/rs_27018/log/mongod.log"#当mongos或mongod实例重新启动时，mongos或mongod会将新条目附加到现有日志文件的末尾logAppend: true
storage:#mongod实例存储其数据的目录。storage.dbPath设置仅适用于mongoddbPath: "/mongodb/replica_sets/rs_27018/data/db"journal:#启用或禁用持久性日志以确保数据文件保持有效和可恢复。enabled: true
processManagement:#启用在后台运行mongos或mongod进程的守护进程模式。fork: true#指定用于保存mongos或mongod进程的进程ID的文件位置，其中mongos或mongod将写入其PIDpidFilePath: "/mongodb/replica_sets/rs_27018/log/mongod.pid"
net:#服务实例绑定所有IP，有副作用，副本集初始化的时候，节点名字会自动设置为本地域名，而不是ip#bindIpAll: true#服务实例绑定的IPbindIp: localhost,192.168.30.129#bindIp#绑定的端口port: 27018
replication:#副本集的名称replSetName: kwz_rs
  1. 启动节点服务：
    /usr/local/mongodb/bin/mongod -f /mongodb/replica_sets/rs_27018/mongod.conf
    在这里插入图片描述

创建仲裁节点

  1. 建立存放数据和日志的目录
# 主节点
mkdir -p /mongodb/replica_sets/rs_27019/log
mkdir -p /mongodb/replica_sets/rs_27019/data/db
  1. 或修改配置文件
vim /mongodb/replica_sets/rs_27019/mongod.conf

systemLog:#MongoDB发送所有日志输出的目标指定为文件destination: file#mongod或mongos应向其发送所有诊断日志记录信息的日志文件的路径path: "/mongodb/replica_sets/rs_27018/log/mongod.log"#当mongos或mongod实例重新启动时，mongos或mongod会将新条目附加到现有日志文件的末尾logAppend: true
storage:#mongod实例存储其数据的目录。storage.dbPath设置仅适用于mongoddbPath: "/mongodb/replica_sets/rs_27018/data/db"journal:#启用或禁用持久性日志以确保数据文件保持有效和可恢复。enabled: true
processManagement:#启用在后台运行mongos或mongod进程的守护进程模式。fork: true#指定用于保存mongos或mongod进程的进程ID的文件位置，其中mongos或mongod将写入其PIDpidFilePath: "/mongodb/replica_sets/rs_27018/log/mongod.pid"
net:#服务实例绑定所有IP，有副作用，副本集初始化的时候，节点名字会自动设置为本地域名，而不是ip#bindIpAll: true#服务实例绑定的IPbindIp: localhost,192.168.30.129#bindIp#绑定的端口port: 27018
replication:#副本集的名称replSetName: kwz_rs
  1. 启动节点服务：
    /usr/local/mongodb/bin/mongod -f /mongodb/replica_sets/rs_27018/mongod.conf
    在这里插入图片描述

初始化配置副本集和主节点

用客户端连接主节点（27017）
/usr/local/mongodb/bin/mongo --host=localhost --port=27017
连接成功之后，许多命令不能用，需要初始化副本集才行，使用默认的配置来初始化副本集：
rs.initiate()

{"info2" : "no configuration specified. Using a default configuration for the set","me" : "localhost:27017","ok" : 1,"$clusterTime" : {"clusterTime" : Timestamp(1601049270, 1),"signature" : {"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),"keyId" : NumberLong(0)}},"operationTime" : Timestamp(1601049270, 1)
}
kwz_rs:SECONDARY>
kwz_rs:SECONDARY>
kwz_rs:PRIMARY>
  1. “ok”的值为1则说明创建成功
  2. 命令行提示符发生变化，变成了一个从节点角色，此时默认不能读写。稍等片刻，回车，变成主节 点，如上图显示的
    这时候执行show dbs就有数据了：
kwz_rs:PRIMARY> show dbs;
admin   0.000GB
config  0.000GB
local   0.000GB

查看副本集的配置

在27017上执行副本集中当前节点的默认节点配置

kwz_rs:PRIMARY> rs.config()
{# 副本集配置数据存储的主键值，默认就是副本集的名字"_id" : "kwz_rs","version" : 1,"protocolVersion" : NumberLong(1),"writeConcernMajorityJournalDefault" : true,# 副本集成员数组,此时只有27017一个"members" : [{"_id" : 0,"host" : "localhost:27017",# 该成员不 是仲裁节点"arbiterOnly" : false,"buildIndexes" : true,"hidden" : false,# 优先级（权重值）"priority" : 1,"tags" : {},"slaveDelay" : NumberLong(0),"votes" : 1}],# 副本集的参数配置"settings" : {"chainingAllowed" : true,"heartbeatIntervalMillis" : 2000,"heartbeatTimeoutSecs" : 10,"electionTimeoutMillis" : 10000,"catchUpTimeoutMillis" : -1,"catchUpTakeoverDelayMillis" : 30000,"getLastErrorModes" : {},"getLastErrorDefaults" : {"w" : 1,"wtimeout" : 0},"replicaSetId" : ObjectId("5f6e12b681a01e73db9b210a")}
}

值得注意的是 副本集rs.conf()的查看命令，本质查询的是 system.replset 的表中的数据，它是在local库下面

查看副本集状态

检查副本集状态，从其他成员发送的心跳包中获得的数据反映副本集的当前状态，通过rs.status()命令
在27017上查看副本集状态：

kwz_rs:PRIMARY> rs.status()
{# 副本集的名字"set" : "kwz_rs","date" : ISODate("2020-09-25T16:38:25.293Z"),# 状态正常"myState" : 1,"term" : NumberLong(1),"syncingTo" : "","syncSourceHost" : "","syncSourceId" : -1,"heartbeatIntervalMillis" : NumberLong(2000),"majorityVoteCount" : 1,"writeMajorityCount" : 1,"optimes" : {"lastCommittedOpTime" : {"ts" : Timestamp(1601051900, 1),"t" : NumberLong(1)},"lastCommittedWallTime" : ISODate("2020-09-25T16:38:20.800Z"),"readConcernMajorityOpTime" : {"ts" : Timestamp(1601051900, 1),"t" : NumberLong(1)},"readConcernMajorityWallTime" : ISODate("2020-09-25T16:38:20.800Z"),"appliedOpTime" : {"ts" : Timestamp(1601051900, 1),"t" : NumberLong(1)},"durableOpTime" : {"ts" : Timestamp(1601051900, 1),"t" : NumberLong(1)},"lastAppliedWallTime" : ISODate("2020-09-25T16:38:20.800Z"),"lastDurableWallTime" : ISODate("2020-09-25T16:38:20.800Z")},"lastStableRecoveryTimestamp" : Timestamp(1601051850, 1),"lastStableCheckpointTimestamp" : Timestamp(1601051850, 1),"electionCandidateMetrics" : {"lastElectionReason" : "electionTimeout","lastElectionDate" : ISODate("2020-09-25T15:54:30.537Z"),"electionTerm" : NumberLong(1),"lastCommittedOpTimeAtElection" : {"ts" : Timestamp(0, 0),"t" : NumberLong(-1)},"lastSeenOpTimeAtElection" : {"ts" : Timestamp(1601049270, 1),"t" : NumberLong(-1)},"numVotesNeeded" : 1,"priorityAtElection" : 1,"electionTimeoutMillis" : NumberLong(10000),"newTermStartDate" : ISODate("2020-09-25T15:54:30.567Z"),"wMajorityWriteAvailabilityDate" : ISODate("2020-09-25T15:54:30.580Z")},# 副本集成员数组"members" : [{"_id" : 0,"name" : "localhost:27017",# 健康"health" : 1,"state" : 1,# 主节点"stateStr" : "PRIMARY","uptime" : 89235,"optime" : {"ts" : Timestamp(1601051900, 1),"t" : NumberLong(1)},"optimeDate" : ISODate("2020-09-25T16:38:20Z"),"syncingTo" : "","syncSourceHost" : "","syncSourceId" : -1,"infoMessage" : "","electionTime" : Timestamp(1601049270, 2),"electionDate" : ISODate("2020-09-25T15:54:30Z"),"configVersion" : 1,"self" : true,"lastHeartbeatMessage" : ""}],"ok" : 1,"$clusterTime" : {"clusterTime" : Timestamp(1601051900, 1),"signature" : {"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),"keyId" : NumberLong(0)}},"operationTime" : Timestamp(1601051900, 1)
}

添加副本从节点

在主节点添加从节点，将其他成员加入到副本集中
下面将27018的副本节点添加到副本集中：

kwz_rs:PRIMARY> rs.add("localhost:27018")
{# 说明添加成功"ok" : 1,"$clusterTime" : {"clusterTime" : Timestamp(1601053665, 1),"signature" : {"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),"keyId" : NumberLong(0)}},"operationTime" : Timestamp(1601053665, 1)
}

此时再次查看副本集状态：

kwz_rs:PRIMARY> rs.status()
{"set" : "kwz_rs","date" : ISODate("2020-09-25T17:09:34.680Z"),"myState" : 1,"term" : NumberLong(1),"syncingTo" : "","syncSourceHost" : "","syncSourceId" : -1,"heartbeatIntervalMillis" : NumberLong(2000),"majorityVoteCount" : 2,"writeMajorityCount" : 2,"optimes" : {"lastCommittedOpTime" : {"ts" : Timestamp(1601053770, 1),"t" : NumberLong(1)},"lastCommittedWallTime" : ISODate("2020-09-25T17:09:30.959Z"),"readConcernMajorityOpTime" : {"ts" : Timestamp(1601053770, 1),"t" : NumberLong(1)},"readConcernMajorityWallTime" : ISODate("2020-09-25T17:09:30.959Z"),"appliedOpTime" : {"ts" : Timestamp(1601053770, 1),"t" : NumberLong(1)},"durableOpTime" : {"ts" : Timestamp(1601053770, 1),"t" : NumberLong(1)},"lastAppliedWallTime" : ISODate("2020-09-25T17:09:30.959Z"),"lastDurableWallTime" : ISODate("2020-09-25T17:09:30.959Z")},"lastStableRecoveryTimestamp" : Timestamp(1601053770, 1),"lastStableCheckpointTimestamp" : Timestamp(1601053770, 1),"electionCandidateMetrics" : {"lastElectionReason" : "electionTimeout","lastElectionDate" : ISODate("2020-09-25T15:54:30.537Z"),"electionTerm" : NumberLong(1),"lastCommittedOpTimeAtElection" : {"ts" : Timestamp(0, 0),"t" : NumberLong(-1)},"lastSeenOpTimeAtElection" : {"ts" : Timestamp(1601049270, 1),"t" : NumberLong(-1)},"numVotesNeeded" : 1,"priorityAtElection" : 1,"electionTimeoutMillis" : NumberLong(10000),"newTermStartDate" : ISODate("2020-09-25T15:54:30.567Z"),"wMajorityWriteAvailabilityDate" : ISODate("2020-09-25T15:54:30.580Z")},# 副本集成员数组中现在有两个了"members" : [{"_id" : 0,"name" : "localhost:27017","health" : 1,"state" : 1,"stateStr" : "PRIMARY","uptime" : 91104,"optime" : {"ts" : Timestamp(1601053770, 1),"t" : NumberLong(1)},"optimeDate" : ISODate("2020-09-25T17:09:30Z"),"syncingTo" : "","syncSourceHost" : "","syncSourceId" : -1,"infoMessage" : "","electionTime" : Timestamp(1601049270, 2),"electionDate" : ISODate("2020-09-25T15:54:30Z"),"configVersion" : 2,"self" : true,"lastHeartbeatMessage" : ""},{"_id" : 1,# 第二个节点的名字"name" : "localhost:27018","health" : 1,"state" : 2,# 它的角色是SECONDARY"stateStr" : "SECONDARY","uptime" : 109,"optime" : {"ts" : Timestamp(1601053770, 1),"t" : NumberLong(1)},"optimeDurable" : {"ts" : Timestamp(1601053770, 1),"t" : NumberLong(1)},"optimeDate" : ISODate("2020-09-25T17:09:30Z"),"optimeDurableDate" : ISODate("2020-09-25T17:09:30Z"),"lastHeartbeat" : ISODate("2020-09-25T17:09:33.236Z"),"lastHeartbeatRecv" : ISODate("2020-09-25T17:09:34.403Z"),"pingMs" : NumberLong(0),"lastHeartbeatMessage" : "","syncingTo" : "localhost:27017","syncSourceHost" : "localhost:27017","syncSourceId" : 0,"infoMessage" : "","configVersion" : 2}],"ok" : 1,"$clusterTime" : {"clusterTime" : Timestamp(1601053770, 1),"signature" : {"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),"keyId" : NumberLong(0)}},"operationTime" : Timestamp(1601053770, 1)
}

添加仲裁从节点

将27019作为仲裁节点，添加到副本集中：

kwz_rs:PRIMARY> rs.addArb("localhost:27019")
{"ok" : 1,"$clusterTime" : {"clusterTime" : Timestamp(1601054101, 1),"signature" : {"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),"keyId" : NumberLong(0)}},"operationTime" : Timestamp(1601054101, 1)
}

查看副本集状态：

kwz_rs:PRIMARY> rs.status()
{"set" : "kwz_rs","date" : ISODate("2020-09-25T17:15:46.933Z"),"myState" : 1,"term" : NumberLong(1),"syncingTo" : "","syncSourceHost" : "","syncSourceId" : -1,"heartbeatIntervalMillis" : NumberLong(2000),"majorityVoteCount" : 2,"writeMajorityCount" : 2,"optimes" : {"lastCommittedOpTime" : {"ts" : Timestamp(1601054140, 1),"t" : NumberLong(1)},"lastCommittedWallTime" : ISODate("2020-09-25T17:15:40.991Z"),"readConcernMajorityOpTime" : {"ts" : Timestamp(1601054140, 1),"t" : NumberLong(1)},"readConcernMajorityWallTime" : ISODate("2020-09-25T17:15:40.991Z"),"appliedOpTime" : {"ts" : Timestamp(1601054140, 1),"t" : NumberLong(1)},"durableOpTime" : {"ts" : Timestamp(1601054140, 1),"t" : NumberLong(1)},"lastAppliedWallTime" : ISODate("2020-09-25T17:15:40.991Z"),"lastDurableWallTime" : ISODate("2020-09-25T17:15:40.991Z")},"lastStableRecoveryTimestamp" : Timestamp(1601054130, 1),"lastStableCheckpointTimestamp" : Timestamp(1601054130, 1),"electionCandidateMetrics" : {"lastElectionReason" : "electionTimeout","lastElectionDate" : ISODate("2020-09-25T15:54:30.537Z"),"electionTerm" : NumberLong(1),"lastCommittedOpTimeAtElection" : {"ts" : Timestamp(0, 0),"t" : NumberLong(-1)},"lastSeenOpTimeAtElection" : {"ts" : Timestamp(1601049270, 1),"t" : NumberLong(-1)},"numVotesNeeded" : 1,"priorityAtElection" : 1,"electionTimeoutMillis" : NumberLong(10000),"newTermStartDate" : ISODate("2020-09-25T15:54:30.567Z"),"wMajorityWriteAvailabilityDate" : ISODate("2020-09-25T15:54:30.580Z")},# 副本集成员数组中现在有三个了"members" : [{"_id" : 0,"name" : "localhost:27017","health" : 1,"state" : 1,"stateStr" : "PRIMARY","uptime" : 91476,"optime" : {"ts" : Timestamp(1601054140, 1),"t" : NumberLong(1)},"optimeDate" : ISODate("2020-09-25T17:15:40Z"),"syncingTo" : "","syncSourceHost" : "","syncSourceId" : -1,"infoMessage" : "","electionTime" : Timestamp(1601049270, 2),"electionDate" : ISODate("2020-09-25T15:54:30Z"),"configVersion" : 3,"self" : true,"lastHeartbeatMessage" : ""},{"_id" : 1,"name" : "localhost:27018","health" : 1,"state" : 2,"stateStr" : "SECONDARY","uptime" : 481,"optime" : {"ts" : Timestamp(1601054140, 1),"t" : NumberLong(1)},"optimeDurable" : {"ts" : Timestamp(1601054140, 1),"t" : NumberLong(1)},"optimeDate" : ISODate("2020-09-25T17:15:40Z"),"optimeDurableDate" : ISODate("2020-09-25T17:15:40Z"),"lastHeartbeat" : ISODate("2020-09-25T17:15:45.481Z"),"lastHeartbeatRecv" : ISODate("2020-09-25T17:15:45.505Z"),"pingMs" : NumberLong(0),"lastHeartbeatMessage" : "","syncingTo" : "localhost:27017","syncSourceHost" : "localhost:27017","syncSourceId" : 0,"infoMessage" : "","configVersion" : 3},{"_id" : 2,"name" : "localhost:27019","health" : 1,"state" : 7,"stateStr" : "ARBITER","uptime" : 45,"lastHeartbeat" : ISODate("2020-09-25T17:15:45.492Z"),"lastHeartbeatRecv" : ISODate("2020-09-25T17:15:45.510Z"),"pingMs" : NumberLong(0),"lastHeartbeatMessage" : "","syncingTo" : "","syncSourceHost" : "","syncSourceId" : -1,"infoMessage" : "","configVersion" : 3}],"ok" : 1,"$clusterTime" : {"clusterTime" : Timestamp(1601054140, 1),"signature" : {"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),"keyId" : NumberLong(0)}},"operationTime" : Timestamp(1601054140, 1)
}

副本集数据读写测试

主节点写入和读取数据

登陆27017主节点，进行写入和读取数据操作：

/usr/local/mongodb/bin/mongo --host localhost --port 27017

kwz_rs:PRIMARY> use article
switched to db article
kwz_rs:PRIMARY> db
article
kwz_rs:PRIMARY> db.comment.insert({"articleid":"001","content":"本篇论文纯属虚构","userId":"1001","nickName":"hanhan","createDatetime":new Date()})
WriteResult({ "nInserted" : 1 })
kwz_rs:PRIMARY> db.comment.find()
{ "_id" : ObjectId("5f6f07a88c6d2fbab4118f14"), "articleid" : "001", "content" : "本篇论文纯属虚构", "userId" : "1001", "nickName" : "hanhan", "createDatetime" : ISODate("2020-09-26T09:19:36.729Z") }

如上所示，我们在27017主节点进行插入和读取操作，均正常

从节点写入和读取数据

登陆27018从节点，进行写入和读取数据操作

/usr/local/mongodb/bin/mongo --host localhost --port 27018

kwz_rs:SECONDARY> show dbs
2020-09-26T17:27:32.202+0800 E  QUERY    [js] uncaught exception: Error: listDatabases failed:{"operationTime" : Timestamp(1601112444, 1),"ok" : 0,"errmsg" : "not master and slaveOk=false","code" : 13435,"codeName" : "NotMasterNoSlaveOk","$clusterTime" : {"clusterTime" : Timestamp(1601112444, 1),"signature" : {"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),"keyId" : NumberLong(0)}}
} :
_getErrorWithCode@src/mongo/shell/utils.js:25:13
Mongo.prototype.getDBs/<@src/mongo/shell/mongo.js:135:19
Mongo.prototype.getDBs@src/mongo/shell/mongo.js:87:12
shellHelper.show@src/mongo/shell/utils.js:906:13
shellHelper@src/mongo/shell/utils.js:790:15
@(shellhelp2):1:1

可以发现不能读取集合的数据，有个"errmsg" : “not master and slaveOk=false”,可见当前节点只是数据的一个备份，不是slave节点，无法读取数据，写入当然更不行。默认情况下，从节点是没有读写权限的，可以增加读的权限，但需要进行设置。
设置读操作权限，允许从成员上进行读的操作：

rs.slaveOk()或者rs.slaveOk(true)

同理，如果想取消从节点的读取权限，设置为：

rs.slaveOk(false)

这时候再看一下，就有了：

kwz_rs:SECONDARY> show dbs
admin    0.000GB
article  0.000GB
config   0.000GB
local    0.000GB

kwz_rs:SECONDARY> use article
switched to db article
kwz_rs:SECONDARY> show collections
comment
kwz_rs:SECONDARY> db.comment.find()
{ "_id" : ObjectId("5f6f07a88c6d2fbab4118f14"), "articleid" : "001", "content" : "本篇论文纯属虚构", "userId" : "1001", "nickName" : "hanhan", "createDatetime" : ISODate("2020-09-26T09:19:36.729Z") }
kwz_rs:SECONDARY> db.comment.insert({"articleid":"002","content":"本篇论文纯属虚构","userId":"1001","nickName":"hanhan","createDatetime":new Date()})
WriteCommandError({"operationTime" : Timestamp(1601112924, 1),"ok" : 0,"errmsg" : "not master","code" : 10107,"codeName" : "NotMaster","$clusterTime" : {"clusterTime" : Timestamp(1601112924, 1),"signature" : {"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),"keyId" : NumberLong(0)}}
})

仲裁节点查看

登陆27019仲裁节点

kwz_rs:ARBITER> rs.slaveOk()
kwz_rs:ARBITER> show dbs
local  0.000GB
kwz_rs:ARBITER> use local
switched to db local
kwz_rs:ARBITER> show collections
replset.election
replset.minvalid
replset.oplogTruncateAfterPoint
startup_log
system.replset
system.rollback.id
kwz_rs:ARBITER>

可见仲裁节点不存放任何业务数据，只存放了副本集配置等数据

主节点的选举原则

MongoDB在副本集中，会自动进行主节点的选举，触发主节点选举的条件主要有三个，分别为：

  • 主节点故障
  • 主节点网络不可达（默认心跳时间为10s，超过10s即认为网络不可达）
  • 人工干预

一旦触发选举 ，会根据一定规则进行主节点的选举，选举规则是根据票数的多少来决定的

  • 票数最高，则获胜
  • 若票数相同，且都获得了“大多数”成员的投票支持的，此时，数据新的节点会获胜，数据的新旧是通过操作日志oplog进行对比的

副本集配置中的priority（优先级）对投票选举影响极大，一般情况下默认为1，它的可选范围是0-1000，相当于额外增加了0-1000票数，指定较高的值，使成员更有资格成为主要成员，更低的值可使成员更不符合条件， 通过rs.conf()可以看到集群优先级的配置。一般主节点和副本节点的优先级各为1，默认都有一票，而仲裁节点的优先级必须是0，不能为别的值。它不具备选举权，但是具备投票权（这也很好理解，仲裁节点你都没有数据，怎么可能给你选举权呢）。

优先级的设置

  • 查看副本级配置
kwz_rs:PRIMARY> rs.conf()
{"_id" : "kwz_rs","version" : 3,"protocolVersion" : NumberLong(1),"writeConcernMajorityJournalDefault" : true,"members" : [{"_id" : 0,"host" : "localhost:27017","arbiterOnly" : false,"buildIndexes" : true,"hidden" : false,"priority" : 1,"tags" : {},"slaveDelay" : NumberLong(0),"votes" : 1},{"_id" : 1,"host" : "localhost:27018","arbiterOnly" : false,"buildIndexes" : true,"hidden" : false,"priority" : 1,"tags" : {},"slaveDelay" : NumberLong(0),"votes" : 1},{"_id" : 2,"host" : "localhost:27019","arbiterOnly" : true,"buildIndexes" : true,"hidden" : false,"priority" : 0,"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("5f6e12b681a01e73db9b210a")}
}

可以看到27018副本级节点原来的优先级1，现在我们将它改为2，让它默认有2票

  • 将配置导入conf_temp
conf_temp=rs.config()
  • 将27018副本节点优先级设为2（这里数组的index默认是从0开始的）
conf_temp.members[1].priority=2
  • 重新加载conf_temp配置
kwz_rs:PRIMARY> rs.reconfig(conf_temp)
{"ok" : 1,"$clusterTime" : {"clusterTime" : Timestamp(1601130737, 1),"signature" : {"hash" : BinData(0,"AAAAAAAAAAAAAAAAAAAAAAAAAAA="),"keyId" : NumberLong(0)}},"operationTime" : Timestamp(1601130737, 1)
}
  • 再次查看副本集配置信息
kwz_rs:PRIMARY> rs.conf()
{"_id" : "kwz_rs","version" : 4,"protocolVersion" : NumberLong(1),"writeConcernMajorityJournalDefault" : true,"members" : [{"_id" : 0,"host" : "localhost:27017","arbiterOnly" : false,"buildIndexes" : true,"hidden" : false,"priority" : 1,"tags" : {},"slaveDelay" : NumberLong(0),"votes" : 1},{"_id" : 1,"host" : "localhost:27018","arbiterOnly" : false,"buildIndexes" : true,"hidden" : false,"priority" : 2,"tags" : {},"slaveDelay" : NumberLong(0),"votes" : 1},{"_id" : 2,"host" : "localhost:27019","arbiterOnly" : true,"buildIndexes" : true,"hidden" : false,"priority" : 0,"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("5f6e12b681a01e73db9b210a")}
}

可以看到27018节点的优先级已经变为2了

高可用测试

副本节点选举为主节点测试

如上所示，当副本节点的priority大于主节点的priority，此时，27017的主节点自动蜕变为副本节点，而27018的副本节点被选举为主节点，完成切换

副本节点故障测试

关闭27018副本节点、此时主节点还在，没有触发选举操作。此时，往主节点里面插入数据：

db.comment.insert({"_id":"4","articleid":"100001","content":"秋天里的第一杯奶茶","userId":"1002","nickName":"去苏州一起喝","createDatetime":new Date("2019-0805T22:08:15.522Z"),"likeNum":NumberInt(1000)})
WriteResult({ "nInserted" : 1 })

再次启动27018副本节点：

/usr/local/mongodb/bin/mongod -f  /mongodb/replica_sets/rs_27018/mongod.conf

此时，之前27017主节点同步的数据同步过来了

kwz_rs:SECONDARY> db.comment.find()
{ "_id" : "4", "articleid" : "100001", "content" : "秋天里的第一杯奶茶", "userId" : "1002", "nickName" : "去苏州一起喝", "createDatetime" : ISODate("1970-01-01T00:00:00Z"), "likeNum" : 1000 }
{ "_id" : ObjectId("5f6f5dc39ef50a5bad627ea5") }
{ "_id" : ObjectId("5f6f5db29ef50a5bad627ea4") }

主节点故障测试

此时关闭27017主节点，从节点和仲裁节点对27017的心跳失败，当失败超过10秒，此时因为没有主节点了，会自动发起投票进行主节点的选取，副本节点只有27018，27019仲裁节点只有投票权没有选举权，因此27019仲裁节点投一票给27018，27018自带一票，共两票。被选举为主节点，此时具备了读写功能，如下：

kwz_rs:PRIMARY> db.comment.insert({"_id":"5","articleid":"100001","content":"秋天里的第一杯奶茶","userId":"1002","nickName":"去苏州一起喝","createDatetime":new Date("2019-0805T22:08:15.522Z"),"likeNum":NumberInt(1000)})
WriteResult({ "nInserted" : 1 })

仲裁节点和主节点故障测试

演示仲裁节点和主节点故障，步骤如下：

  1. 先恢复一主一从一仲裁
  2. 关掉仲裁节点27019
  3. 关掉主节点27018

此时登陆27017节点，发现27017还是从节点，副本集现在没有主节点了，现在副本集是只读状态，无法进行写入操作了
此时如果想触发主节点的选举，再加入一个成员即可

  • 如果只加入27019仲裁节点成员，则主节点一定是27017，因为没得选了，仲裁节点不参与选举， 但参与投票
  • 如果只加入27018节点，会发起选举。因为27017和27018都是两票，则按照谁数据新，谁当主节点

仲裁节点和从节点故障测试

  • 先恢复一主一从一仲裁
  • 关掉仲裁节点27019
  • 关掉现在的副本节点27018

等待10s后，27017主节点自动降级为副本节点了。

小结

本篇文章主要介绍了Linux环境下mongoDB 4副本集模式搭建步骤以及它的选举规则，在搭建完之后又分别进行了高可用测试。

参考：

  1. https://www.bilibili.com/video/BV14Z4y1p7Xu?p=29
  2. https://github.com/nuptkwz/notes/tree/master/technology/mongo
http://www.jmfq.cn/news/4825171.html

相关文章：

  • 注册网站能赚钱吗/域名注册新网
  • 网站淘宝推广怎么做/如何做营销策划方案
  • 门户网站建设好处/今日头条新闻视频
  • 长沙微营销/石家庄seo
  • 网站制作销售术语/2022最火营销方案
  • 湖南省金力电力建设有限公司 网站/seo排名怎么看
  • 在线旅游攻略网站建设方案/软文推广平台排名
  • 电脑上怎么下载字体到wordpress/商丘 峰少 seo博客
  • 做幼儿园网站/广州网页seo排名
  • 专业做皮草的网站/网站自助搭建
  • 做cpa能用什么网站/宁波超值关键词优化
  • 网站正建设中/2023年6月份又封城了
  • 深圳最新新闻事件/网店产品seo如何优化
  • 太原建站模板搭建/百度客户管理系统登录
  • 做经营性的网站需要注册什么/网站seo排名优化
  • 网站的建设需要多少钱/关键词推广效果
  • 网站开发赚钱/seo营销推广平台
  • 哈尔滨做网站/营销方式
  • 网站建设技巧饣金手指排名27/seo推广代运营
  • 网站开发demo是什么/百度权重是什么意思
  • 网站建设的好不好/google首页
  • 网站标题会影响吗/优化服务是什么意思
  • 新疆建设厅造价网站/链接推广
  • 网站设计流程软件/网络推广方式有哪些
  • 上海自适应网站建设/搜索引擎整合营销
  • 礼信堂 网站开发/什么关键词可以搜到那种
  • 成都哪里做网站好/百度推广登录入口电脑
  • 如何建立一个大型的网站/网站推广seo设置
  • 网站舆情监控怎么做/seo排名优化什么意思
  • 邯郸网站建设地方/百度广告太多