2.搭建 MongoDB (v6.0) 副本集记录2023-11-23

正文

副本集概述

副本集（Replica Set）是一组带有故障转移的 MongoDB 实例组成的集群，由一个主（Primary）服务器和多个从（Secondary）服务器构成。通过Replication，将数据的更新由Primary推送到其他实例上，在一定的延迟之后，每个MongoDB实例维护相同的数据集副本。通过维护冗余的数据库副本，能够实现数据的异地备份，读写分离和自动故障转移。
MongoDB 副本集中没有固定的主节点，在启动后，多个服务节点间将自动选举产生一个主节点。该主节点被称为primary，一个或多个从节点被称为secondaries。primary基本上就是master节点，不同之处在于primary节点在不同时间可能是不同的服务器。如果当前的主节点失效了，副本集中的其余节点将会试图选出一个新的主节点。

节点说明

MongoDB副本集架构通过部署多种节点来达到高可用和读写分离的效果，每个副本集实例包含一个主节点（Primary节点）、一个或多个从节点（Secondary节点）、隐藏节点（Hidden节点）、仲裁节点（Arbiter节点）和可选的一个或多个只读节点（ReadOnly节点）。其中主节点、从节点和隐藏节点合起来统称为“主备节点”。各节点的说明如下：

主节点（Primary节点）

负责执行和响应数据读写请求。每个副本集实例中只能有一个主节点。主节点将其数据集的所有更改记录在其操作日志（即oplog小于50 GB）中。

从节点（Secondary节点）

通过操作日志（oplog）同步主节点的数据，可在主节点故障时通过选举成为新的主节点，保障高可用。
通过从节点的连接地址进行连接时，只能读取数据不能写入数据。
从节点具有高可用保障，即某个从节点故障时，系统会自动将其与隐藏节点切换，若未自动切换，您可以自行切换，从节点的连接地址保持不变。

触发节点的角色切换后，会产生1次30秒内的连接闪断，建议您在业务低峰期操作或确保应用具备重连机制。

隐藏节点（Hidden节点）

通过操作日志（oplog）同步主节点的数据，可在从节点故障时接替该故障节点成为新的从节点，也可在只读节点故障时接替该故障节点成为新的只读节点，保障高可用。
隐藏节点仅用作高可用，对客户端不可见。
隐藏节点不在“主节点的备用列表”中，不会被选举为主节点，但会参与投票选举主节点。
每个副本集实例中只能有一个隐藏节点。

仲裁节点（Arbiter节点）

仲裁节点，只是用来投票，且投票的权重只能为1，不复制数据，也不能提升为primary。
仲裁节点常用于节点数量是偶数的副本集中。
通常将Arbiter部署在业务服务器上，切忌将其部署在Primary节点或Secondary节点服务器上。

只读节点（ReadOnly节点）

通过操作日志（oplog）从延迟最低的主节点或从节点同步数据，应用于有大量读请求的场景，以减轻主节点和从节点的访问压力。两个或以上只读节点可以使用ReadOnly Connection String URI连接实现读请求负载均衡。
只读节点具有高可用保障，即某个只读节点故障时，系统会自动将其与隐藏节点切换，若未自动切换，您可以自行切换，只读节点的连接地址保持不变。

触发节点的角色切换后，会产生1次30秒内的连接闪断，建议您在业务低峰期操作或确保应用具备重连机制。

只读节点具有独立的连接地址，适合独立系统直连访问，与已有主从节点的连接互不干扰。
只读节点不在“主节点的备用列表”中，不会被选举为主节点，也不会参与投票选举主节点。

副本集部署架构

MongoDB 6.x 官方介绍副本节点最少为3台，建议副本集成员为奇数，最多50个副本节点，最多7个节点参与选举。
限制副本节点的数量，主要是因为一个集群中过多的副本节点，增加了复制的成本，反而拖累了集群的整体性能。
太多的副本节点参与选举，也会增加选举的时间。而官方建议奇数的节点，是为了避免脑裂的发生。

副本集搭建过程

环境准备

主机名	IP地址	成员
MongoDB-Master	172.16.70.181	主节点
MongoDB-Slave01	172.16.70.182	从节点
MongoDB-Slave02	172.16.70.183	从节点

 # 三个节点统一设置，这里以 MongoDB-Master 为例
[root@MongoDB-Master ~]# cat /etc/redhat-release
CentOS Linux release 7.9.2009 (Core)
[root@MongoDB-Master ~]# uname -r
3.10.0-1160.el7.x86_64
 
# 修改ulimit 系统资源限制
[root@MongoDB-Master ~]# cat /etc/security/limits.conf
....末行追加以下内容....
root    soft    nproc   65535
root    hard    nproc   65535
root    hard    nofile  65535
root    soft    nofile  65535
 
[root@MongoDB-Master ~]# setenforce 0
[root@MongoDB-Master ~]# sed -i.bak '7s/enforcing/disabled/' /etc/selinux/config
 
[root@MongoDB-Master ~]# systemctl stop firewalld
[root@MongoDB-Master ~]# systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
   Active: inactive (dead)
     Docs: man:firewalld(1)

安装 MongoDB 6.0

 # 使用Yum方式安装当前最新稳定版本，这里以 MongoDB-Master 为例，其他两从节点一样操作。
[root@MongoDB-Master ~]# cat /etc/yum.repos.d/mongodb-org-6.0.repo
[mongodb-org-6.0]
name=MongoDB Repository
baseurl=https://repo.mongodb.org/yum/redhat/$releasever/mongodb-org/6.0/x86_64/
gpgcheck=1
enabled=1
gpgkey=https://www.mongodb.org/static/pgp/server-6.0.asc
 
[root@MongoDB-Master ~]# yum install -y mongodb-org
 
=========================================================================================================
# 如要安装特定版本的 MongoDB，请单独指定每个组件包并将版本号附加到包名称，例如
yum install -y mongodb-org-6.0.10 mongodb-org-database-6.0.10 mongodb-org-server-6.0.10 mongodb-org-mongos-6.0.10 mongodb-org-tools-6.0.10
# yum当更新版本可用时升级软件包。为防止意外升级，请固定包。要固定包，请将以下exclude指令添加到您的/etc/yum.conf文件中
exclude=mongodb-org,mongodb-org-database,mongodb-org-server,mongodb-mongosh,mongodb-org-mongos,mongodb-org-tools
=========================================================================================================
# 查看安装版本
[root@MongoDB-Master ~]# mongod --version
db version v6.0.11
Build Info: {
    "version": "6.0.11",
    "gitVersion": "f797f841eaf1759c770271ae00c88b92b2766eed",
    "openSSLVersion": "OpenSSL 1.0.1e-fips 11 Feb 2013",
    "modules": [],
    "allocator": "tcmalloc",
    "environment": {
        "distmod": "rhel70",
        "distarch": "x86_64",
        "target_arch": "x86_64"
    }
}
 
# 修改配置文件 (bindIp: 127.0.0.1,172.16.70.181) 
[root@MongoDB-Master ~]# grep -Ev "^$" /etc/mongod.conf
# mongod.conf
# for documentation of all options, see:
#   http://docs.mongodb.org/manual/reference/configuration-options/
# where to write logging data.
systemLog:
  destination: file
  logAppend: true
  path: /var/log/mongodb/mongod.log
# Where and how to store data.
storage:
  dbPath: /var/lib/mongo
  journal:
    enabled: true
#  engine:
#  wiredTiger:
# how the process runs
processManagement:
  timeZoneInfo: /usr/share/zoneinfo
# network interfaces
net:
  port: 27017
  # 注意：本机的ip地址。否则后面进行副本集初始化的时候可能会失败！
  bindIp: 127.0.0.1,172.16.70.181  # Enter 0.0.0.0,:: to bind to all IPv4 and IPv6 addresses or, alternatively, use the net.bindIpAll setting.
#security:
#operationProfiling:
replication:
   # 定义副本集名称
   replSetName: testrs0
#sharding:
## Enterprise-Only Options
#auditLog:
#snmp:
 
# 确保运行MongoDB的用户有权访问相关目录
[root@MongoDB-Master ~]# grep mongo /etc/passwd
mongod:x:997:996:mongod:/var/lib/mongo:/bin/false
[root@MongoDB-Master ~]# ls -ld /var/log/mongodb/mongod.log /var/lib/mongo
drwxr-xr-x 4 mongod mongod   4096 Oct 20 10:25 /var/lib/mongo
-rw-r----- 1 mongod mongod 171974 Oct 20 10:22 /var/log/mongodb/mongod.log
 
# 启动MongoDB
[root@MongoDB-Master ~]# systemctl start mongod && systemctl enable mongod
[root@MongoDB-Master ~]# systemctl list-units | grep mongod
mongod.service                                  loaded active running   MongoDB Database Server
 
[root@MongoDB-Master ~]# ps axu | grep mongod
mongod     1563  1.8  2.4 2805700 97536 ?       Ssl  11:26   0:01 /usr/bin/mongod -f /etc/mongod.conf
root       1703  0.0  0.0 112808   968 pts/0    S+   11:27   0:00 grep --color=auto mongod
 
[root@MongoDB-Master ~]# netstat -ntpl | grep mongod
tcp        0      0 172.16.70.181:27017     0.0.0.0:*               LISTEN      1563/mongod
tcp        0      0 127.0.0.1:27017         0.0.0.0:*               LISTEN      1563/mongod
[root@MongoDB-Master ~]# ls -l /tmp/mongodb-27017.sock
srwx------ 1 mongod mongod 0 Oct 20 11:26 /tmp/mongodb-27017.sock

部署副本集

这里的_id与配置文件mongod.conf中replSetName保持一致。

 # 在任意节点执行 rs.initiate，这里选择在MongoDB-Master操作初始化。
[root@MongoDB-Master ~]# mongosh
test> rs.initiate( {
...    _id : "testrs0",
...    members: [
...       { _id: 0, host: "172.16.70.181:27017" },
...       { _id: 1, host: "172.16.70.182:27017" },
...       { _id: 2, host: "172.16.70.183:27017" }
...    ]
... })
{ ok: 1 }
 
# 查看副本集配置，确保只有一个主节点
testrs0 [direct: primary] test> rs.conf()
{
  _id: 'testrs0',
  version: 1,
  term: 1,
  members: [
    {
      _id: 0,
      host: '172.16.70.181:27017',
      arbiterOnly: false,   # 是否为仲裁者，默认为false
      buildIndexes: true,   # 是否为构建索引成员
      hidden: false,        # 是否为隐藏成员
      priority: 1,          # 范围0~1000，默认为1，值大为主节点primary，值为0则不能成为primay（仲裁）
      tags: {},
      secondaryDelaySecs: Long("0"),   # 从节点复制延迟时间，单位秒s
      votes: 1                         # 选举投票的数量
    },
    {
      _id: 1,
      host: '172.16.70.182:27017',
      arbiterOnly: false,
      buildIndexes: true,
      hidden: false,
      priority: 1,           # 默认为1
      tags: {},
      secondaryDelaySecs: Long("0"),
      votes: 1
    },
    {
      _id: 2,
      host: '172.16.70.183:27017',
      arbiterOnly: false,
      buildIndexes: true,
      hidden: false,
      priority: 1,        # 默认为1
      tags: {},
      secondaryDelaySecs: Long("0"),
      votes: 1
    }
  ],
  protocolVersion: Long("1"),
  writeConcernMajorityJournalDefault: true,
  settings: {
    chainingAllowed: true,
    heartbeatIntervalMillis: 2000,
    heartbeatTimeoutSecs: 10,
    electionTimeoutMillis: 10000,
    catchUpTimeoutMillis: -1,
    catchUpTakeoverDelayMillis: 30000,
    getLastErrorModes: {},
    getLastErrorDefaults: { w: 1, wtimeout: 0 },
    replicaSetId: ObjectId("6531f7207c8f661d6f787810")
  }
}
 
 
testrs0 [direct: primary] test> rs.status()
{
  set: 'testrs0',                              # 副本集名称
  date: ISODate("2023-10-20T04:06:56.352Z"),   # 当前时间
  myState: 1,                                  # 成员的副本状态(0~10)；常见 1：PRIMARY，2：SECONDARY，7：ARBITER，8：DOWN
  term: Long("2"),                             # 获得选举的票数
  syncSourceHost: '',                          # 实例同步成员的主机名
  syncSourceId: -1,                            # 实例同成员名称
  heartbeatIntervalMillis: Long("2000"),       # 心跳频率，毫秒ms
  majorityVoteCount: 2,                        # 被选举为主节点所需要的票数
  writeMajorityCount: 2,                       # 满足写操作所需要的票数
  votingMembersCount: 3,                       # 该副本集中成员数量
  writableVotingMembersCount: 3,               # 有投票权的成员数量
  optimes: {
    lastCommittedOpTime: { ts: Timestamp({ t: 1697774807, i: 1 }), t: Long("2") },
    lastCommittedWallTime: ISODate("2023-10-20T04:06:47.335Z"),
    readConcernMajorityOpTime: { ts: Timestamp({ t: 1697774807, i: 1 }), t: Long("2") },
    appliedOpTime: { ts: Timestamp({ t: 1697774807, i: 1 }), t: Long("2") },
    durableOpTime: { ts: Timestamp({ t: 1697774807, i: 1 }), t: Long("2") },
    lastAppliedWallTime: ISODate("2023-10-20T04:06:47.335Z"),
    lastDurableWallTime: ISODate("2023-10-20T04:06:47.335Z")
  },
  lastStableRecoveryTimestamp: Timestamp({ t: 1697774793, i: 1 }),
  electionCandidateMetrics: {
    lastElectionReason: 'stepUpRequestSkipDryRun',
    lastElectionDate: ISODate("2023-10-20T04:04:37.304Z"),
    electionTerm: Long("2"),
    lastCommittedOpTimeAtElection: { ts: Timestamp({ t: 1697774676, i: 1 }), t: Long("1") },
    lastSeenOpTimeAtElection: { ts: Timestamp({ t: 1697774676, i: 1 }), t: Long("1") },
    numVotesNeeded: 2,
    priorityAtElection: 1,
    electionTimeoutMillis: Long("10000"),
    priorPrimaryMemberId: 1,
    numCatchUpOps: Long("0"),
    newTermStartDate: ISODate("2023-10-20T04:04:37.311Z"),
    wMajorityWriteAvailabilityDate: ISODate("2023-10-20T04:04:38.331Z")
  },
  electionParticipantMetrics: {
    votedForCandidate: true,
    electionTerm: Long("1"),
    lastVoteDate: ISODate("2023-10-20T03:42:36.120Z"),
    electionCandidateMemberId: 1,
    voteReason: '',
    lastAppliedOpTimeAtElection: { ts: Timestamp({ t: 1697773344, i: 1 }), t: Long("-1") },
    maxAppliedOpTimeInSet: { ts: Timestamp({ t: 1697773344, i: 1 }), t: Long("-1") },
    priorityAtElection: 1
  },
  members: [
    {
      _id: 0,                          # 副本集中节点编号
      name: '172.16.70.181:27017',     # 服务器名称及端口号
      health: 1,                       # 健康状态；1为正常，0为异常
      state: 1,                        # 当前状态；数值小为primary，数值大为secondary
      stateStr: 'PRIMARY',             # 主节点(PRIMARY)，从节点(SECONDARY)
      uptime: 2424,                    # 在线时间（秒）
      optime: { ts: Timestamp({ t: 1697774807, i: 1 }), t: Long("2") },    # 最后一次应用日志(oplog)信息
      optimeDate: ISODate("2023-10-20T04:06:47.000Z"),                     # 最后一次应用日志(oplog)时间
      lastAppliedWallTime: ISODate("2023-10-20T04:06:47.335Z"),            # 该成员在主节点上应用的最后一次操作的时间
      lastDurableWallTime: ISODate("2023-10-20T04:06:47.335Z"),            # 最后一次写入成员日志的操作首次在主节点上应用时的时间
      syncSourceHost: '',
      syncSourceId: -1,
      infoMessage: '',
      electionTime: Timestamp({ t: 1697774677, i: 1 }),                    # primary从操作日志选举时间戳信息
      electionDate: ISODate("2023-10-20T04:04:37.000Z"),                   # 被选定为primary的时间
      configVersion: 1,                                                    # 副本集版本
      configTerm: 2,
      self: true,
      lastHeartbeatMessage: ''
    },
    {
      _id: 1,
      name: '172.16.70.182:27017',
      health: 1,            
      state: 2,               # 数值小为primary，数值大为secondary
      stateStr: 'SECONDARY',  # 从节点
      uptime: 84,
      optime: { ts: Timestamp({ t: 1697774807, i: 1 }), t: Long("2") },
      optimeDurable: { ts: Timestamp({ t: 1697774807, i: 1 }), t: Long("2") },
      optimeDate: ISODate("2023-10-20T04:06:47.000Z"),
      optimeDurableDate: ISODate("2023-10-20T04:06:47.000Z"),
      lastAppliedWallTime: ISODate("2023-10-20T04:06:47.335Z"),
      lastDurableWallTime: ISODate("2023-10-20T04:06:47.335Z"),
      lastHeartbeat: ISODate("2023-10-20T04:06:55.647Z"),
      lastHeartbeatRecv: ISODate("2023-10-20T04:06:55.575Z"),
      pingMs: Long("0"),
      lastHeartbeatMessage: '',
      syncSourceHost: '172.16.70.183:27017',
      syncSourceId: 2,
      infoMessage: '',
      configVersion: 1,
      configTerm: 2
    },
    {
      _id: 2,
      name: '172.16.70.183:27017',
      health: 1,              
      state: 2,               # 数值小为primary，数值大为secondary
      stateStr: 'SECONDARY',  # 从节点
      uptime: 1471,
      optime: { ts: Timestamp({ t: 1697774807, i: 1 }), t: Long("2") },
      optimeDurable: { ts: Timestamp({ t: 1697774807, i: 1 }), t: Long("2") },
      optimeDate: ISODate("2023-10-20T04:06:47.000Z"),
      optimeDurableDate: ISODate("2023-10-20T04:06:47.000Z"),
      lastAppliedWallTime: ISODate("2023-10-20T04:06:47.335Z"),
      lastDurableWallTime: ISODate("2023-10-20T04:06:47.335Z"),
      lastHeartbeat: ISODate("2023-10-20T04:06:55.561Z"),
      lastHeartbeatRecv: ISODate("2023-10-20T04:06:54.598Z"),
      pingMs: Long("0"),
      lastHeartbeatMessage: '',
      syncSourceHost: '172.16.70.181:27017',
      syncSourceId: 0,
      infoMessage: '',
      configVersion: 1,
      configTerm: 2
    }
  ],
  ok: 1,
  '$clusterTime': {
    clusterTime: Timestamp({ t: 1697774807, i: 1 }),
    signature: {
      hash: Binary.createFromBase64("AAAAAAAAAAAAAAAAAAAAAAAAAAA=", 0),
      keyId: Long("0")
    }
  },
  operationTime: Timestamp({ t: 1697774807, i: 1 })
}
testrs0 [direct: primary] test>

复制功能测试

 # 在主节点(172.16.70.181)上新增mydb库，并创建myColl文档
[root@MongoDB-Master ~]# mongosh
testrs0 [direct: primary] test>
 
testrs0 [direct: primary] test> show dbs
admin    80.00 KiB
config  208.00 KiB
local   484.00 KiB
testrs0 [direct: primary] test> use mydb
switched to db mydb
testrs0 [direct: primary] mydb> db.myColl.insertOne({ name: "zhang" })
{
  acknowledged: true,
  insertedId: ObjectId("65361759be7d5c1abe9d83ee")
}
testrs0 [direct: primary] mydb> db.myColl.find()
[ { _id: ObjectId("65361759be7d5c1abe9d83ee"), name: 'zhang' } ]
 
 
# 在从节点(172.16.70.182/183)上查看复制同步数据结果
[root@MongoDB-Slave01 ~]# mongosh
testrs0 [direct: secondary] test> use mydb
switched to db mydb
testrs0 [direct: secondary] mydb> show collections
myColl
testrs0 [direct: secondary] mydb> db.myColl.find()
MongoServerError: not primary and secondaryOk=false - consider using db.getMongo().setReadPref() or readPreference in the connection string
 
# MongoServerError 报错！
# 这是因为mongodb默认是从主节点读写数据的，副本节点上不允许读，需要设置副本节点可以读
 
testrs0 [direct: secondary] mydb> db.getMongo().setReadPref('secondary')
 
testrs0 [direct: secondary] mydb> db.myColl.find()
[ { _id: ObjectId("65361759be7d5c1abe9d83ee"), name: 'zhang' } ]
 
# 此时，主节点数据已经同步到从节点上

故障转移功能测试

 # 假设主节点(172.16.70.181)故障
[root@MongoDB-Master ~]# systemctl stop mongod
[root@MongoDB-Master ~]# netstat -ntpl | grep mongod
 
# 登录从节点查看副本集状态
[root@MongoDB-Slave01 ~]# mongosh
testrs0 [direct: primary] test> rs.status()
{
  set: 'testrs0',
  date: ISODate("2023-10-23T07:55:53.369Z"),
  myState: 1,
  term: Long("2"),
  syncSourceHost: '',
  syncSourceId: -1,
  heartbeatIntervalMillis: Long("2000"),
  majorityVoteCount: 2,
  writeMajorityCount: 2,
  votingMembersCount: 3,
  writableVotingMembersCount: 3,
  optimes: {
    lastCommittedOpTime: { ts: Timestamp({ t: 1698047743, i: 1 }), t: Long("2") },
    lastCommittedWallTime: ISODate("2023-10-23T07:55:43.519Z"),
    readConcernMajorityOpTime: { ts: Timestamp({ t: 1698047743, i: 1 }), t: Long("2") },
    appliedOpTime: { ts: Timestamp({ t: 1698047743, i: 1 }), t: Long("2") },
    durableOpTime: { ts: Timestamp({ t: 1698047743, i: 1 }), t: Long("2") },
    lastAppliedWallTime: ISODate("2023-10-23T07:55:43.519Z"),
    lastDurableWallTime: ISODate("2023-10-23T07:55:43.519Z")
  },
  lastStableRecoveryTimestamp: Timestamp({ t: 1698047693, i: 1 }),
  electionCandidateMetrics: {
    lastElectionReason: 'stepUpRequestSkipDryRun',
    lastElectionDate: ISODate("2023-10-23T07:51:13.449Z"),
    electionTerm: Long("2"),
    lastCommittedOpTimeAtElection: { ts: Timestamp({ t: 1698047468, i: 1 }), t: Long("1") },
    lastSeenOpTimeAtElection: { ts: Timestamp({ t: 1698047468, i: 1 }), t: Long("1") },
    numVotesNeeded: 2,
    priorityAtElection: 1,
    electionTimeoutMillis: Long("10000"),
    priorPrimaryMemberId: 0,
    numCatchUpOps: Long("0"),
    newTermStartDate: ISODate("2023-10-23T07:51:13.456Z"),
    wMajorityWriteAvailabilityDate: ISODate("2023-10-23T07:51:14.459Z")
  },
  electionParticipantMetrics: {
    votedForCandidate: true,
    electionTerm: Long("1"),
    lastVoteDate: ISODate("2023-10-23T07:47:58.216Z"),
    electionCandidateMemberId: 0,
    voteReason: '',
    lastAppliedOpTimeAtElection: { ts: Timestamp({ t: 1698047267, i: 1 }), t: Long("-1") },
    maxAppliedOpTimeInSet: { ts: Timestamp({ t: 1698047267, i: 1 }), t: Long("-1") },
    priorityAtElection: 1
  },
  members: [
    {
      _id: 0,
      name: '172.16.70.181:27017',
      health: 0,
      state: 8,
      stateStr: '(not reachable/healthy)',
      uptime: 0,
      optime: { ts: Timestamp({ t: 0, i: 0 }), t: Long("-1") },
      optimeDurable: { ts: Timestamp({ t: 0, i: 0 }), t: Long("-1") },
      optimeDate: ISODate("1970-01-01T00:00:00.000Z"),
      optimeDurableDate: ISODate("1970-01-01T00:00:00.000Z"),
      lastAppliedWallTime: ISODate("2023-10-23T07:51:14.906Z"),
      lastDurableWallTime: ISODate("2023-10-23T07:51:14.906Z"),
      lastHeartbeat: ISODate("2023-10-23T07:55:52.462Z"),
      lastHeartbeatRecv: ISODate("2023-10-23T07:51:28.493Z"),
      pingMs: Long("0"),
      lastHeartbeatMessage: 'Error connecting to 172.16.70.181:27017 :: caused by :: Connection refused',     # 提示: Error
      syncSourceHost: '',
      syncSourceId: -1,
      infoMessage: '',
      configVersion: 1,
      configTerm: 2
    },
    {
      _id: 1,
      name: '172.16.70.182:27017',
      health: 1,
      state: 1,
      stateStr: 'PRIMARY',
      uptime: 1005,
      optime: { ts: Timestamp({ t: 1698047743, i: 1 }), t: Long("2") },
      optimeDate: ISODate("2023-10-23T07:55:43.000Z"),
      lastAppliedWallTime: ISODate("2023-10-23T07:55:43.519Z"),
      lastDurableWallTime: ISODate("2023-10-23T07:55:43.519Z"),
      syncSourceHost: '',
      syncSourceId: -1,
      infoMessage: '',
      electionTime: Timestamp({ t: 1698047473, i: 1 }),
      electionDate: ISODate("2023-10-23T07:51:13.000Z"),
      configVersion: 1,
      configTerm: 2,
      self: true,
      lastHeartbeatMessage: ''
    },
    {
      _id: 2,
      name: '172.16.70.183:27017',
      health: 1,
      state: 2,
      stateStr: 'SECONDARY',
      uptime: 486,
      optime: { ts: Timestamp({ t: 1698047743, i: 1 }), t: Long("2") },
      optimeDurable: { ts: Timestamp({ t: 1698047743, i: 1 }), t: Long("2") },
      optimeDate: ISODate("2023-10-23T07:55:43.000Z"),
      optimeDurableDate: ISODate("2023-10-23T07:55:43.000Z"),
      lastAppliedWallTime: ISODate("2023-10-23T07:55:43.519Z"),
      lastDurableWallTime: ISODate("2023-10-23T07:55:43.519Z"),
      lastHeartbeat: ISODate("2023-10-23T07:55:52.043Z"),
      lastHeartbeatRecv: ISODate("2023-10-23T07:55:52.568Z"),
      pingMs: Long("0"),
      lastHeartbeatMessage: '',
      syncSourceHost: '172.16.70.182:27017',
      syncSourceId: 1,
      infoMessage: '',
      configVersion: 1,
      configTerm: 2
    }
  ],
  ok: 1,
  '$clusterTime': {
    clusterTime: Timestamp({ t: 1698047743, i: 1 }),
    signature: {
      hash: Binary.createFromBase64("AAAAAAAAAAAAAAAAAAAAAAAAAAA=", 0),
      keyId: Long("0")
    }
  },
  operationTime: Timestamp({ t: 1698047743, i: 1 })
}
testrs0 [direct: primary] test>
 
# 此次，从节点(172.16.70.182)经过选举后，成为新的主节点。
# 原主节点(172.16.70.181)故障恢复后，将成为新的主节点(172.16.70.182)的从节点。
# 如果想实例预设成为主节点，可设置更高优先级priority（默认优先级为1,m值是0~1000之间的数字,数字越大优先级越高,m=0,则此节点永远不能成为主节点）
# 即先移除rs.remove("ip:port")，再新增rs.add( { host: "ip:port", priority: Num } )

更改副本集优先级

 # 查看当前副本集配置
rs.conf()
 
# n为 _id 值，从0开始为第一个节点，1为第二个节点，....
# 默认优先级为1,m值是0~1000之间的数字,数字越大优先级越高,m=0,则此节点永远不能成为主节点（仲裁）
cfg.members[n].priority = m
 
# 重新配置当前副本集
rs.reconfig(cfg)

新增副本集成员

 # 必须在主节点上操作
# 新增具有默认投票和优先级的成员到副本集
rs.add( { host: "mongodbd4.example.net:27017" } )
rs.add( "mongodbd4.example.net:27017" )
 
# 新增优先级0的成员到副本集
rs.add( { host: "mongodbd4.example.net:27017", priority: 0 } )
 
# 新增仲裁者成员到副本集
rs.add( { host: "mongodb3.example.net:27017", arbiterOnly: true } )
rs.add("mongodb3.example.net:27017", true)

删除副本成员

 rs.remove("mongod3.example.net:27017")
rs.remove("mongod3.example.net")

替换副本集成员

 cfg = rs.conf()
cfg.members[0].host = "mongo2.example.net"
rs.reconfig(cfg)

posted @ 2023-11-23 17:55 讲文张字阅读(1262) 评论(0) 编辑收藏举报

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历史上的今天：
2020-11-23 配置VRRP负载分担

搭建 MongoDB (v6.0) 副本集记录

副本集概述

节点说明

副本集部署架构

副本集搭建过程

环境准备

安装 MongoDB 6.0

部署副本集

复制功能测试

故障转移功能测试

更改副本集优先级

新增副本集成员

删除副本成员

替换副本集成员

公告

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	# 三个节点统一设置，这里以 MongoDB-Master 为例
	[root@MongoDB-Master ~]# cat /etc/redhat-release
	CentOS Linux release 7.9.2009 (Core)
	[root@MongoDB-Master ~]# uname -r
	3.10.0-1160.el7.x86_64

	# 修改ulimit 系统资源限制
	[root@MongoDB-Master ~]# cat /etc/security/limits.conf
	....末行追加以下内容....
	root soft nproc 65535
	root hard nproc 65535
	root hard nofile 65535
	root soft nofile 65535

	[root@MongoDB-Master ~]# setenforce 0
	[root@MongoDB-Master ~]# sed -i.bak '7s/enforcing/disabled/' /etc/selinux/config

	[root@MongoDB-Master ~]# systemctl stop firewalld
	[root@MongoDB-Master ~]# systemctl status firewalld
	● firewalld.service - firewalld - dynamic firewall daemon
	Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
	Active: inactive (dead)
	Docs: man:firewalld(1)

	# 使用Yum方式安装当前最新稳定版本，这里以 MongoDB-Master 为例，其他两从节点一样操作。
	[root@MongoDB-Master ~]# cat /etc/yum.repos.d/mongodb-org-6.0.repo
	[mongodb-org-6.0]
	name=MongoDB Repository
	baseurl=https://repo.mongodb.org/yum/redhat/$releasever/mongodb-org/6.0/x86_64/
	gpgcheck=1
	enabled=1
	gpgkey=https://www.mongodb.org/static/pgp/server-6.0.asc

	[root@MongoDB-Master ~]# yum install -y mongodb-org

	=========================================================================================================
	# 如要安装特定版本的 MongoDB，请单独指定每个组件包并将版本号附加到包名称，例如
	yum install -y mongodb-org-6.0.10 mongodb-org-database-6.0.10 mongodb-org-server-6.0.10 mongodb-org-mongos-6.0.10 mongodb-org-tools-6.0.10
	# yum当更新版本可用时升级软件包。为防止意外升级，请固定包。要固定包，请将以下exclude指令添加到您的/etc/yum.conf文件中
	exclude=mongodb-org,mongodb-org-database,mongodb-org-server,mongodb-mongosh,mongodb-org-mongos,mongodb-org-tools
	=========================================================================================================
	# 查看安装版本
	[root@MongoDB-Master ~]# mongod --version
	db version v6.0.11
	Build Info: {
	"version": "6.0.11",
	"gitVersion": "f797f841eaf1759c770271ae00c88b92b2766eed",
	"openSSLVersion": "OpenSSL 1.0.1e-fips 11 Feb 2013",
	"modules": [],
	"allocator": "tcmalloc",
	"environment": {
	"distmod": "rhel70",
	"distarch": "x86_64",
	"target_arch": "x86_64"
	}
	}

	# 修改配置文件 (bindIp: 127.0.0.1,172.16.70.181)
	[root@MongoDB-Master ~]# grep -Ev "^$" /etc/mongod.conf
	# mongod.conf
	# for documentation of all options, see:
	# http://docs.mongodb.org/manual/reference/configuration-options/
	# where to write logging data.
	systemLog:
	destination: file
	logAppend: true
	path: /var/log/mongodb/mongod.log
	# Where and how to store data.
	storage:
	dbPath: /var/lib/mongo
	journal:
	enabled: true
	# engine:
	# wiredTiger:
	# how the process runs
	processManagement:
	timeZoneInfo: /usr/share/zoneinfo
	# network interfaces
	net:
	port: 27017
	# 注意：本机的ip地址。否则后面进行副本集初始化的时候可能会失败！
	bindIp: 127.0.0.1,172.16.70.181 # Enter 0.0.0.0,:: to bind to all IPv4 and IPv6 addresses or, alternatively, use the net.bindIpAll setting.
	#security:
	#operationProfiling:
	replication:
	# 定义副本集名称
	replSetName: testrs0
	#sharding:
	## Enterprise-Only Options
	#auditLog:
	#snmp:

	# 确保运行MongoDB的用户有权访问相关目录
	[root@MongoDB-Master ~]# grep mongo /etc/passwd
	mongod:x:997:996:mongod:/var/lib/mongo:/bin/false
	[root@MongoDB-Master ~]# ls -ld /var/log/mongodb/mongod.log /var/lib/mongo
	drwxr-xr-x 4 mongod mongod 4096 Oct 20 10:25 /var/lib/mongo
	-rw-r----- 1 mongod mongod 171974 Oct 20 10:22 /var/log/mongodb/mongod.log

	# 启动MongoDB
	[root@MongoDB-Master ~]# systemctl start mongod && systemctl enable mongod
	[root@MongoDB-Master ~]# systemctl list-units \| grep mongod
	mongod.service loaded active running MongoDB Database Server

	[root@MongoDB-Master ~]# ps axu \| grep mongod
	mongod 1563 1.8 2.4 2805700 97536 ? Ssl 11:26 0:01 /usr/bin/mongod -f /etc/mongod.conf
	root 1703 0.0 0.0 112808 968 pts/0 S+ 11:27 0:00 grep --color=auto mongod

	[root@MongoDB-Master ~]# netstat -ntpl \| grep mongod
	tcp 0 0 172.16.70.181:27017 0.0.0.0:* LISTEN 1563/mongod
	tcp 0 0 127.0.0.1:27017 0.0.0.0:* LISTEN 1563/mongod
	[root@MongoDB-Master ~]# ls -l /tmp/mongodb-27017.sock
	srwx------ 1 mongod mongod 0 Oct 20 11:26 /tmp/mongodb-27017.sock

	# 在任意节点执行 rs.initiate，这里选择在MongoDB-Master操作初始化。
	[root@MongoDB-Master ~]# mongosh
	test> rs.initiate( {
	... _id : "testrs0",
	... members: [
	... { _id: 0, host: "172.16.70.181:27017" },
	... { _id: 1, host: "172.16.70.182:27017" },
	... { _id: 2, host: "172.16.70.183:27017" }
	... ]
	... })
	{ ok: 1 }

	# 查看副本集配置，确保只有一个主节点
	testrs0 [direct: primary] test> rs.conf()
	{
	_id: 'testrs0',
	version: 1,
	term: 1,
	members: [
	{
	_id: 0,
	host: '172.16.70.181:27017',
	arbiterOnly: false, # 是否为仲裁者，默认为false
	buildIndexes: true, # 是否为构建索引成员
	hidden: false, # 是否为隐藏成员
	priority: 1, # 范围0~1000，默认为1，值大为主节点primary，值为0则不能成为primay（仲裁）
	tags: {},
	secondaryDelaySecs: Long("0"), # 从节点复制延迟时间，单位秒s
	votes: 1 # 选举投票的数量
	},
	{
	_id: 1,
	host: '172.16.70.182:27017',
	arbiterOnly: false,
	buildIndexes: true,
	hidden: false,
	priority: 1, # 默认为1
	tags: {},
	secondaryDelaySecs: Long("0"),
	votes: 1
	},
	{
	_id: 2,
	host: '172.16.70.183:27017',
	arbiterOnly: false,
	buildIndexes: true,
	hidden: false,
	priority: 1, # 默认为1
	tags: {},
	secondaryDelaySecs: Long("0"),
	votes: 1
	}
	],
	protocolVersion: Long("1"),
	writeConcernMajorityJournalDefault: true,
	settings: {
	chainingAllowed: true,
	heartbeatIntervalMillis: 2000,
	heartbeatTimeoutSecs: 10,
	electionTimeoutMillis: 10000,
	catchUpTimeoutMillis: -1,
	catchUpTakeoverDelayMillis: 30000,
	getLastErrorModes: {},
	getLastErrorDefaults: { w: 1, wtimeout: 0 },
	replicaSetId: ObjectId("6531f7207c8f661d6f787810")
	}
	}


	testrs0 [direct: primary] test> rs.status()
	{
	set: 'testrs0', # 副本集名称
	date: ISODate("2023-10-20T04:06:56.352Z"), # 当前时间
	myState: 1, # 成员的副本状态(0~10)；常见 1：PRIMARY，2：SECONDARY，7：ARBITER，8：DOWN
	term: Long("2"), # 获得选举的票数
	syncSourceHost: '', # 实例同步成员的主机名
	syncSourceId: -1, # 实例同成员名称
	heartbeatIntervalMillis: Long("2000"), # 心跳频率，毫秒ms
	majorityVoteCount: 2, # 被选举为主节点所需要的票数
	writeMajorityCount: 2, # 满足写操作所需要的票数
	votingMembersCount: 3, # 该副本集中成员数量
	writableVotingMembersCount: 3, # 有投票权的成员数量
	optimes: {
	lastCommittedOpTime: { ts: Timestamp({ t: 1697774807, i: 1 }), t: Long("2") },
	lastCommittedWallTime: ISODate("2023-10-20T04:06:47.335Z"),
	readConcernMajorityOpTime: { ts: Timestamp({ t: 1697774807, i: 1 }), t: Long("2") },
	appliedOpTime: { ts: Timestamp({ t: 1697774807, i: 1 }), t: Long("2") },
	durableOpTime: { ts: Timestamp({ t: 1697774807, i: 1 }), t: Long("2") },
	lastAppliedWallTime: ISODate("2023-10-20T04:06:47.335Z"),
	lastDurableWallTime: ISODate("2023-10-20T04:06:47.335Z")
	},
	lastStableRecoveryTimestamp: Timestamp({ t: 1697774793, i: 1 }),
	electionCandidateMetrics: {
	lastElectionReason: 'stepUpRequestSkipDryRun',
	lastElectionDate: ISODate("2023-10-20T04:04:37.304Z"),
	electionTerm: Long("2"),
	lastCommittedOpTimeAtElection: { ts: Timestamp({ t: 1697774676, i: 1 }), t: Long("1") },
	lastSeenOpTimeAtElection: { ts: Timestamp({ t: 1697774676, i: 1 }), t: Long("1") },
	numVotesNeeded: 2,
	priorityAtElection: 1,
	electionTimeoutMillis: Long("10000"),
	priorPrimaryMemberId: 1,
	numCatchUpOps: Long("0"),
	newTermStartDate: ISODate("2023-10-20T04:04:37.311Z"),
	wMajorityWriteAvailabilityDate: ISODate("2023-10-20T04:04:38.331Z")
	},
	electionParticipantMetrics: {
	votedForCandidate: true,
	electionTerm: Long("1"),
	lastVoteDate: ISODate("2023-10-20T03:42:36.120Z"),
	electionCandidateMemberId: 1,
	voteReason: '',
	lastAppliedOpTimeAtElection: { ts: Timestamp({ t: 1697773344, i: 1 }), t: Long("-1") },
	maxAppliedOpTimeInSet: { ts: Timestamp({ t: 1697773344, i: 1 }), t: Long("-1") },
	priorityAtElection: 1
	},
	members: [
	{
	_id: 0, # 副本集中节点编号
	name: '172.16.70.181:27017', # 服务器名称及端口号
	health: 1, # 健康状态；1为正常，0为异常
	state: 1, # 当前状态；数值小为primary，数值大为secondary
	stateStr: 'PRIMARY', # 主节点(PRIMARY)，从节点(SECONDARY)
	uptime: 2424, # 在线时间（秒）
	optime: { ts: Timestamp({ t: 1697774807, i: 1 }), t: Long("2") }, # 最后一次应用日志(oplog)信息
	optimeDate: ISODate("2023-10-20T04:06:47.000Z"), # 最后一次应用日志(oplog)时间
	lastAppliedWallTime: ISODate("2023-10-20T04:06:47.335Z"), # 该成员在主节点上应用的最后一次操作的时间
	lastDurableWallTime: ISODate("2023-10-20T04:06:47.335Z"), # 最后一次写入成员日志的操作首次在主节点上应用时的时间
	syncSourceHost: '',
	syncSourceId: -1,
	infoMessage: '',
	electionTime: Timestamp({ t: 1697774677, i: 1 }), # primary从操作日志选举时间戳信息
	electionDate: ISODate("2023-10-20T04:04:37.000Z"), # 被选定为primary的时间
	configVersion: 1, # 副本集版本
	configTerm: 2,
	self: true,
	lastHeartbeatMessage: ''
	},
	{
	_id: 1,
	name: '172.16.70.182:27017',
	health: 1,
	state: 2, # 数值小为primary，数值大为secondary
	stateStr: 'SECONDARY', # 从节点
	uptime: 84,
	optime: { ts: Timestamp({ t: 1697774807, i: 1 }), t: Long("2") },
	optimeDurable: { ts: Timestamp({ t: 1697774807, i: 1 }), t: Long("2") },
	optimeDate: ISODate("2023-10-20T04:06:47.000Z"),
	optimeDurableDate: ISODate("2023-10-20T04:06:47.000Z"),
	lastAppliedWallTime: ISODate("2023-10-20T04:06:47.335Z"),
	lastDurableWallTime: ISODate("2023-10-20T04:06:47.335Z"),
	lastHeartbeat: ISODate("2023-10-20T04:06:55.647Z"),
	lastHeartbeatRecv: ISODate("2023-10-20T04:06:55.575Z"),
	pingMs: Long("0"),
	lastHeartbeatMessage: '',
	syncSourceHost: '172.16.70.183:27017',
	syncSourceId: 2,
	infoMessage: '',
	configVersion: 1,
	configTerm: 2
	},
	{
	_id: 2,
	name: '172.16.70.183:27017',
	health: 1,
	state: 2, # 数值小为primary，数值大为secondary
	stateStr: 'SECONDARY', # 从节点
	uptime: 1471,
	optime: { ts: Timestamp({ t: 1697774807, i: 1 }), t: Long("2") },
	optimeDurable: { ts: Timestamp({ t: 1697774807, i: 1 }), t: Long("2") },
	optimeDate: ISODate("2023-10-20T04:06:47.000Z"),
	optimeDurableDate: ISODate("2023-10-20T04:06:47.000Z"),
	lastAppliedWallTime: ISODate("2023-10-20T04:06:47.335Z"),
	lastDurableWallTime: ISODate("2023-10-20T04:06:47.335Z"),
	lastHeartbeat: ISODate("2023-10-20T04:06:55.561Z"),
	lastHeartbeatRecv: ISODate("2023-10-20T04:06:54.598Z"),
	pingMs: Long("0"),
	lastHeartbeatMessage: '',
	syncSourceHost: '172.16.70.181:27017',
	syncSourceId: 0,
	infoMessage: '',
	configVersion: 1,
	configTerm: 2
	}
	],
	ok: 1,
	'$clusterTime': {
	clusterTime: Timestamp({ t: 1697774807, i: 1 }),
	signature: {
	hash: Binary.createFromBase64("AAAAAAAAAAAAAAAAAAAAAAAAAAA=", 0),
	keyId: Long("0")
	}
	},
	operationTime: Timestamp({ t: 1697774807, i: 1 })
	}
	testrs0 [direct: primary] test>

	# 在主节点(172.16.70.181)上新增mydb库，并创建myColl文档
	[root@MongoDB-Master ~]# mongosh
	testrs0 [direct: primary] test>

	testrs0 [direct: primary] test> show dbs
	admin 80.00 KiB
	config 208.00 KiB
	local 484.00 KiB
	testrs0 [direct: primary] test> use mydb
	switched to db mydb
	testrs0 [direct: primary] mydb> db.myColl.insertOne({ name: "zhang" })
	{
	acknowledged: true,
	insertedId: ObjectId("65361759be7d5c1abe9d83ee")
	}
	testrs0 [direct: primary] mydb> db.myColl.find()
	[ { _id: ObjectId("65361759be7d5c1abe9d83ee"), name: 'zhang' } ]


	# 在从节点(172.16.70.182/183)上查看复制同步数据结果
	[root@MongoDB-Slave01 ~]# mongosh
	testrs0 [direct: secondary] test> use mydb
	switched to db mydb
	testrs0 [direct: secondary] mydb> show collections
	myColl
	testrs0 [direct: secondary] mydb> db.myColl.find()
	MongoServerError: not primary and secondaryOk=false - consider using db.getMongo().setReadPref() or readPreference in the connection string

	# MongoServerError 报错！
	# 这是因为mongodb默认是从主节点读写数据的，副本节点上不允许读，需要设置副本节点可以读

	testrs0 [direct: secondary] mydb> db.getMongo().setReadPref('secondary')

	testrs0 [direct: secondary] mydb> db.myColl.find()
	[ { _id: ObjectId("65361759be7d5c1abe9d83ee"), name: 'zhang' } ]

	# 此时，主节点数据已经同步到从节点上

	# 假设主节点(172.16.70.181)故障
	[root@MongoDB-Master ~]# systemctl stop mongod
	[root@MongoDB-Master ~]# netstat -ntpl \| grep mongod

	# 登录从节点查看副本集状态
	[root@MongoDB-Slave01 ~]# mongosh
	testrs0 [direct: primary] test> rs.status()
	{
	set: 'testrs0',
	date: ISODate("2023-10-23T07:55:53.369Z"),
	myState: 1,
	term: Long("2"),
	syncSourceHost: '',
	syncSourceId: -1,
	heartbeatIntervalMillis: Long("2000"),
	majorityVoteCount: 2,
	writeMajorityCount: 2,
	votingMembersCount: 3,
	writableVotingMembersCount: 3,
	optimes: {
	lastCommittedOpTime: { ts: Timestamp({ t: 1698047743, i: 1 }), t: Long("2") },
	lastCommittedWallTime: ISODate("2023-10-23T07:55:43.519Z"),
	readConcernMajorityOpTime: { ts: Timestamp({ t: 1698047743, i: 1 }), t: Long("2") },
	appliedOpTime: { ts: Timestamp({ t: 1698047743, i: 1 }), t: Long("2") },
	durableOpTime: { ts: Timestamp({ t: 1698047743, i: 1 }), t: Long("2") },
	lastAppliedWallTime: ISODate("2023-10-23T07:55:43.519Z"),
	lastDurableWallTime: ISODate("2023-10-23T07:55:43.519Z")
	},
	lastStableRecoveryTimestamp: Timestamp({ t: 1698047693, i: 1 }),
	electionCandidateMetrics: {
	lastElectionReason: 'stepUpRequestSkipDryRun',
	lastElectionDate: ISODate("2023-10-23T07:51:13.449Z"),
	electionTerm: Long("2"),
	lastCommittedOpTimeAtElection: { ts: Timestamp({ t: 1698047468, i: 1 }), t: Long("1") },
	lastSeenOpTimeAtElection: { ts: Timestamp({ t: 1698047468, i: 1 }), t: Long("1") },
	numVotesNeeded: 2,
	priorityAtElection: 1,
	electionTimeoutMillis: Long("10000"),
	priorPrimaryMemberId: 0,
	numCatchUpOps: Long("0"),
	newTermStartDate: ISODate("2023-10-23T07:51:13.456Z"),
	wMajorityWriteAvailabilityDate: ISODate("2023-10-23T07:51:14.459Z")
	},
	electionParticipantMetrics: {
	votedForCandidate: true,
	electionTerm: Long("1"),
	lastVoteDate: ISODate("2023-10-23T07:47:58.216Z"),
	electionCandidateMemberId: 0,
	voteReason: '',
	lastAppliedOpTimeAtElection: { ts: Timestamp({ t: 1698047267, i: 1 }), t: Long("-1") },
	maxAppliedOpTimeInSet: { ts: Timestamp({ t: 1698047267, i: 1 }), t: Long("-1") },
	priorityAtElection: 1
	},
	members: [
	{
	_id: 0,
	name: '172.16.70.181:27017',
	health: 0,
	state: 8,
	stateStr: '(not reachable/healthy)',
	uptime: 0,
	optime: { ts: Timestamp({ t: 0, i: 0 }), t: Long("-1") },
	optimeDurable: { ts: Timestamp({ t: 0, i: 0 }), t: Long("-1") },
	optimeDate: ISODate("1970-01-01T00:00:00.000Z"),
	optimeDurableDate: ISODate("1970-01-01T00:00:00.000Z"),
	lastAppliedWallTime: ISODate("2023-10-23T07:51:14.906Z"),
	lastDurableWallTime: ISODate("2023-10-23T07:51:14.906Z"),
	lastHeartbeat: ISODate("2023-10-23T07:55:52.462Z"),
	lastHeartbeatRecv: ISODate("2023-10-23T07:51:28.493Z"),
	pingMs: Long("0"),
	lastHeartbeatMessage: 'Error connecting to 172.16.70.181:27017 :: caused by :: Connection refused', # 提示: Error
	syncSourceHost: '',
	syncSourceId: -1,
	infoMessage: '',
	configVersion: 1,
	configTerm: 2
	},
	{
	_id: 1,
	name: '172.16.70.182:27017',
	health: 1,
	state: 1,
	stateStr: 'PRIMARY',
	uptime: 1005,
	optime: { ts: Timestamp({ t: 1698047743, i: 1 }), t: Long("2") },
	optimeDate: ISODate("2023-10-23T07:55:43.000Z"),
	lastAppliedWallTime: ISODate("2023-10-23T07:55:43.519Z"),
	lastDurableWallTime: ISODate("2023-10-23T07:55:43.519Z"),
	syncSourceHost: '',
	syncSourceId: -1,
	infoMessage: '',
	electionTime: Timestamp({ t: 1698047473, i: 1 }),
	electionDate: ISODate("2023-10-23T07:51:13.000Z"),
	configVersion: 1,
	configTerm: 2,
	self: true,
	lastHeartbeatMessage: ''
	},
	{
	_id: 2,
	name: '172.16.70.183:27017',
	health: 1,
	state: 2,
	stateStr: 'SECONDARY',
	uptime: 486,
	optime: { ts: Timestamp({ t: 1698047743, i: 1 }), t: Long("2") },
	optimeDurable: { ts: Timestamp({ t: 1698047743, i: 1 }), t: Long("2") },
	optimeDate: ISODate("2023-10-23T07:55:43.000Z"),
	optimeDurableDate: ISODate("2023-10-23T07:55:43.000Z"),
	lastAppliedWallTime: ISODate("2023-10-23T07:55:43.519Z"),
	lastDurableWallTime: ISODate("2023-10-23T07:55:43.519Z"),
	lastHeartbeat: ISODate("2023-10-23T07:55:52.043Z"),
	lastHeartbeatRecv: ISODate("2023-10-23T07:55:52.568Z"),
	pingMs: Long("0"),
	lastHeartbeatMessage: '',
	syncSourceHost: '172.16.70.182:27017',
	syncSourceId: 1,
	infoMessage: '',
	configVersion: 1,
	configTerm: 2
	}
	],
	ok: 1,
	'$clusterTime': {
	clusterTime: Timestamp({ t: 1698047743, i: 1 }),
	signature: {
	hash: Binary.createFromBase64("AAAAAAAAAAAAAAAAAAAAAAAAAAA=", 0),
	keyId: Long("0")
	}
	},
	operationTime: Timestamp({ t: 1698047743, i: 1 })
	}
	testrs0 [direct: primary] test>

	# 此次，从节点(172.16.70.182)经过选举后，成为新的主节点。
	# 原主节点(172.16.70.181)故障恢复后，将成为新的主节点(172.16.70.182)的从节点。
	# 如果想实例预设成为主节点，可设置更高优先级priority（默认优先级为1,m值是0~1000之间的数字,数字越大优先级越高,m=0,则此节点永远不能成为主节点）
	# 即先移除rs.remove("ip:port")，再新增rs.add( { host: "ip:port", priority: Num } )

	# 查看当前副本集配置
	rs.conf()

	# n为 _id 值，从0开始为第一个节点，1为第二个节点，....
	# 默认优先级为1,m值是0~1000之间的数字,数字越大优先级越高,m=0,则此节点永远不能成为主节点（仲裁）
	cfg.members[n].priority = m

	# 重新配置当前副本集
	rs.reconfig(cfg)

	# 必须在主节点上操作
	# 新增具有默认投票和优先级的成员到副本集
	rs.add( { host: "mongodbd4.example.net:27017" } )
	rs.add( "mongodbd4.example.net:27017" )

	# 新增优先级0的成员到副本集
	rs.add( { host: "mongodbd4.example.net:27017", priority: 0 } )

	# 新增仲裁者成员到副本集
	rs.add( { host: "mongodb3.example.net:27017", arbiterOnly: true } )
	rs.add("mongodb3.example.net:27017", true)

	rs.remove("mongod3.example.net:27017")
	rs.remove("mongod3.example.net")

	cfg = rs.conf()
	cfg.members[0].host = "mongo2.example.net"
	rs.reconfig(cfg)