MongoDB设置 Replication Sets 复制集

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MongoDB 高可用可用分两种：

Master-Slave 主从复制：只需要在某一个服务启动时加上–master 参数, 而另一个服务加上–slave 与–source 参数, 即可实现同步。

MongoDB 的最新版本已不再推荐此方案。

Replica Sets 复制集：MongoDB 在 1.6 版本对开发了新功能 replica set, 这比之前的 replication 功能要强大一些, 增加了故障自动切换和自动修复成员节点, 各个 DB 之间数据完全一致, 大大降低了维护成功。auto shard 已经明确说明不支持 replication paris, 建议使用 replica set,replica set 故障切换完全自动。

Replica Sets 的结构非常类似一个集群，其中一个节点如果出现故障, 其它节点马上会将业务接过来而无须停机操作。

MongoDB 设置 Replication Sets 复制集

192.168.110.131(node1)

192.168.110.132(node2)

192.168.110.133(node3)

官方文档：

http://docs.mongoing.com/manual-zh/

部署复制集：

http://docs.mongoing.com/manual-zh/tutorial/deploy-replica-set.html

一、MongoDB 安装

[root@node1 ~]# vim /etc/yum.repos.d/Mongodb.repo

[mongodb-org-3.4]
name=MongoDB Repository
baseurl=https://repo.mongodb.org/yum/RedHat/$releasever/mongodb-org/3.4/x86_64/
gpgcheck=1
enabled=1
gpgkey=https://www.mongodb.org/static/pgp/server-3.4.asc

[root@node1 ~]# yum install -y mongodb-org

[root@node1 ~]# service mongod start
Starting mongod: [OK]

[root@node1 ~]# ps aux|grep mong
mongod 1361 5.7 14.8 351180 35104 ? Sl 01:26 0:01 /usr/bin/mongod -f /etc/mongod.conf

更改数据存放目录：

[root@node1 ~]# mkdir -p /mongodb/data
[root@node1 ~]# chown -R mongod:mongod /mongodb/
[root@node1 ~]# ll /mongodb/
total 4
drwxr-xr-x 2 mongod mongod 4096 May 18 02:04 data

[root@node1 ~]# grep -v “^#” /etc/mongod.conf |grep -v “^$”
systemLog:
destination: file
logAppend: true
path: /var/log/mongodb/mongod.log
storage:
dbPath: /mongodb/data
journal:
enabled: true
processManagement:
fork: true # fork and run in background
pidFilePath: /var/run/mongodb/mongod.pid # location of pidfile
net:
port: 27017
bindIp: 0.0.0.0 # Listen to local interface only, comment to listen on all interfaces.

[root@node1 ~]# service mongod start
Starting mongod: [OK]

node2，node2 与上面一样

二、配置 Replication Sets

介绍一下涉及到的参数

–oplogSize 日志操作文件的大小
–dbpath 数据文件路径

–logpath 日志文件路径

–port 端口号，默认是 27017. 我这里使用的也是这个端口号.

–replSet 复制集的名字，一个 replica sets 中的每个节点的这个参数都要用一个复制集名字，这里是 test.

–replSet test/ 这个后面跟的是其他 standard 节点的 ip 和端口

–maxConns 最大连接数

–fork 后台运行

–logappend 日志文件循环使用，如果日志文件已满，那么新日志覆盖最久日志。

–keyFile 标识同一集群的认证私钥

其中在启动节点时一定要加上 oplogSize 的参数为其设置大小，不然在 64 位操作系统上的 mongodb,oplogs 都相当大 - 可能是 5% 的磁盘空间。
要根据情况设置个合理的值。

v3.4.4 上的参数：

[root@node1 ~]# vim /etc/mongod.conf

replication:
oplogSizeMB: 1024
replSetName: rs0

使用 Keyfile 存取控制部署复制集：

openssl rand -base64 756 > <path-to-keyfile>
chmod 400 <path-to-keyfile>

Configuration File

If using a configuration file, set the security.keyFile option to the keyfile’s path, and the replication.replSetName option to the replica set name:

security:
keyFile: <path-to-keyfile>
replication:
replSetName: <replicaSetName>

Command Line

If using the command line option, start the mongod with the –keyFile and –replSet parameters:

mongod –keyFile <path-to-keyfile> –replSet <replicaSetName>

配置带密钥文件的 Replication Sets：

[root@node1 ~]# openssl rand -base64 756 > /mongodb/mongokey
[root@node1 ~]# cat /mongodb/mongokey
gxpcgjyFj2qE8b9TB/0XbdRVYH9VDb55NY03AHwxCFU58MUjJMeez844i1gaUo/t
…..
…..

[root@node1 ~]# chmod 400 /mongodb/mongokey
[root@node1 ~]# chown mongod:mongod /mongodb/mongokey
[root@node1 ~]# ll /mongodb/
total 8
drwxr-xr-x 4 mongod mongod 4096 May 19 18:39 data
-r——– 1 mongod mongod 1024 May 19 18:29 mongokey

[root@node1 ~]# vim /etc/mongod.conf
#security:
security:
keyFile: /mongodb/mongokey

#operationProfiling:

#replication:
replication:
oplogSizeMB: 1024
replSetName: rs0

[root@node1 ~]# service mongod restart
Stopping mongod: [OK]
Starting mongod: [OK]

[root@node1 ~]# iptables -I INPUT 4 -m state –state NEW -p tcp –dport 27017 -j ACCEPT

复制 hosts 文件：
[root@node1 ~]# rsync -avH –progress ‘-e ssh -p 22’ /etc/hosts root@node2.pancou.com:/mongodb/
[root@node1 ~]# rsync -avH –progress ‘-e ssh -p 22’ /etc/hosts root@node3.pancou.com:/mongodb/
复制密钥文件：
[root@node1 ~]# rsync -avH –progress ‘-e ssh -p 22’ /mongodb/mongokey root@node3.pancou.com:/mongodb/
[root@node1 ~]# rsync -avH –progress ‘-e ssh -p 22’ /mongodb/mongokey root@node3.pancou.com:/mongodb/

复制配置文件：
[root@node1 ~]# rsync -avH –progress ‘-e ssh -p 22’ /etc/mongod.conf root@node2.pancou.com:/etc/
[root@node1 ~]# rsync -avH –progress ‘-e ssh -p 22’ /etc/mongod.conf root@node3.pancou.com:/etc/

注意: 双方都要按照 rsync 和 openssh-clients

[root@node1 ~]# mongo
> help
db.help() help on db methods
db.mycoll.help() help on collection methods
sh.help() sharding helpers
rs.help() replica set helpers
…..

> rs.help()
rs.status() { replSetGetStatus : 1} checks repl set status
rs.initiate() { replSetInitiate : null} initiates set with default settings
rs.initiate(cfg) {replSetInitiate : cfg} initiates set with configuration cfg
rs.conf() get the current configuration object from local.system.replset
…..

> rs.status()
{
“info” : “run rs.initiate(…) if not yet done for the set”,
“ok” : 0,
“errmsg” : “no replset config has been received”,
“code” : 94,
“codeName” : “NotYetInitialized”
}

> rs.initiate()
{
“info2” : “no configuration specified. Using a default configuration for the set”,
“me” : “node1.pancou.com:27017”,
“ok” : 1
}

rs0:OTHER>
rs0:PRIMARY> rs.status()
{
“set” : “rs0”,
“date” : ISODate(“2017-05-18T17:00:49.868Z”),
“myState” : 1,
“term” : NumberLong(1),
“heartbeatIntervalMillis” : NumberLong(2000),
“optimes” : {
“lastCommittedOpTime” : {
“ts” : Timestamp(1495126845, 1),
“t” : NumberLong(1)
},
“appliedOpTime” : {
“ts” : Timestamp(1495126845, 1),
“t” : NumberLong(1)
},
“durableOpTime” : {
“ts” : Timestamp(1495126845, 1),
“t” : NumberLong(1)
}
},
“members” : [
{
“_id” : 0,
“name” : “node1.pancou.com:27017”,
“health” : 1,
“state” : 1,
“stateStr” : “PRIMARY”,
“uptime” : 1239,
“optime” : {
“ts” : Timestamp(1495126845, 1),
“t” : NumberLong(1)
},
“optimeDate” : ISODate(“2017-05-18T17:00:45Z”),
“infoMessage” : “could not find member to sync from”,
“electionTime” : Timestamp(1495126824, 2),
“electionDate” : ISODate(“2017-05-18T17:00:24Z”),
“configVersion” : 1,
“self” : true
}
],
“ok” : 1
}

rs0:PRIMARY> rs.add(“node2.pancou.com”)
{“ok” : 1}
rs0:PRIMARY> rs.add(“node3.pancou.com”)
{“ok” : 1}
rs0:PRIMARY> rs.status()
{
“set” : “rs0”,
“date” : ISODate(“2017-05-18T17:08:47.724Z”),
“myState” : 1,
“term” : NumberLong(1),
“heartbeatIntervalMillis” : NumberLong(2000),
“optimes” : {
“lastCommittedOpTime” : {
“ts” : Timestamp(1495127325, 1),
“t” : NumberLong(1)
},
“appliedOpTime” : {
“ts” : Timestamp(1495127325, 1),
“t” : NumberLong(1)
},
“durableOpTime” : {
“ts” : Timestamp(1495127325, 1),
“t” : NumberLong(1)
}
},
“members” : [
{
“_id” : 0,
“name” : “node1.pancou.com:27017”,
“health” : 1, // 表明状态正常
“state” : 1, // 1 表示是 PRIMARY，2 表示是 slave
“stateStr” : “PRIMARY”, // 表示此机器是主库
“uptime” : 1717,
“optime” : {
“ts” : Timestamp(1495127325, 1),
“t” : NumberLong(1)
},
“optimeDate” : ISODate(“2017-05-18T17:08:45Z”),
“electionTime” : Timestamp(1495126824, 2),
“electionDate” : ISODate(“2017-05-18T17:00:24Z”),
“configVersion” : 3,
“self” : true
},
{
“_id” : 1,
“name” : “node2.pancou.com:27017”,
“health” : 1,
“state” : 2,
“stateStr” : “SECONDARY”,
“uptime” : 64,
“optime” : {
“ts” : Timestamp(1495127325, 1),
“t” : NumberLong(1)
},
“optimeDurable” : {
“ts” : Timestamp(1495127325, 1),
“t” : NumberLong(1)
},
“optimeDate” : ISODate(“2017-05-18T17:08:45Z”),
“optimeDurableDate” : ISODate(“2017-05-18T17:08:45Z”),
“lastHeartbeat” : ISODate(“2017-05-18T17:08:46.106Z”),
“lastHeartbeatRecv” : ISODate(“2017-05-18T17:08:47.141Z”),
“pingMs” : NumberLong(0),
“syncingTo” : “node1.pancou.com:27017”,
“configVersion” : 3
},
{
“_id” : 2,
“name” : “node3.pancou.com:27017”,
“health” : 1,
“state” : 2,
“stateStr” : “SECONDARY”,
“uptime” : 55,
“optime” : {
“ts” : Timestamp(1495127325, 1),
“t” : NumberLong(1)
},
“optimeDurable” : {
“ts” : Timestamp(1495127325, 1),
“t” : NumberLong(1)
},
“optimeDate” : ISODate(“2017-05-18T17:08:45Z”),
“optimeDurableDate” : ISODate(“2017-05-18T17:08:45Z”),
“lastHeartbeat” : ISODate(“2017-05-18T17:08:46.195Z”),
“lastHeartbeatRecv” : ISODate(“2017-05-18T17:08:46.924Z”),
“pingMs” : NumberLong(0),
“syncingTo” : “node2.pancou.com:27017”,
“configVersion” : 3
}
],
“ok” : 1
}

rs0:PRIMARY> db.isMaster()
{
“hosts” : [
“node1.pancou.com:27017”,
“node2.pancou.com:27017”,
“node3.pancou.com:27017”
],
“setName” : “rs0”,
“setVersion” : 3,
“ismaster” : true,
“secondary” : false,
“primary” : “node1.pancou.com:27017”,
“me” : “node1.pancou.com:27017”,
“electionId” : ObjectId(“7fffffff0000000000000001”),
“lastWrite” : {
“opTime” : {
“ts” : Timestamp(1495127705, 1),
“t” : NumberLong(1)
},
“lastWriteDate” : ISODate(“2017-05-18T17:15:05Z”)
},
“maxBsonObjectSize” : 16777216,
“maxMessageSizeBytes” : 48000000,
“maxWriteBatchSize” : 1000,
“localTime” : ISODate(“2017-05-18T17:15:11.146Z”),
“maxWireVersion” : 5,
“minWireVersion” : 0,
“readOnly” : false,
“ok” : 1
}

rs0:PRIMARY> use testdb
rs0:PRIMARY> show collections
testcoll
rs0:PRIMARY> db.testcoll.find()
{“_id” : ObjectId(“591dd9f965cc255a5373aefa”), “name” : “tom”, “age” : 25 }

到从库上查看：

node2:

rs0:SECONDARY> rs.slaveOk()
rs0:SECONDARY> show dbs
admin 0.000GB
local 0.000GB
testdb 0.000GB
rs0:SECONDARY> use testdb
switched to db testdb
rs0:SECONDARY> show collections
testcoll
rs0:SECONDARY> db.testcoll.find()
{“_id” : ObjectId(“591dd9f965cc255a5373aefa”), “name” : “tom”, “age” : 25 }
rs0:SECONDARY>

node3:

rs0:SECONDARY> rs.slaveOk()
rs0:SECONDARY> show dbs
admin 0.000GB
local 0.000GB
testdb 0.000GB
rs0:SECONDARY> use testdb
switched to db testdb
rs0:SECONDARY> show collections
testcoll
rs0:SECONDARY> db.testcoll.find()
{“_id” : ObjectId(“591dd9f965cc255a5373aefa”), “name” : “tom”, “age” : 25 }
rs0:SECONDARY>

主从操作日志

rs0:PRIMARY> use local
switched to db local
rs0:PRIMARY> show collections
me
oplog.rs
replset.election
replset.minvalid
startup_log
system.replset
rs0:PRIMARY> db.oplog.rs.find()
{“ts” : Timestamp(1495126824, 1), “h” : NumberLong(“3056083863196084673”), “v” : 2, “op” : “n”, “ns” : “”, “o” : {“msg” : “initiating set”} }
{“ts” : Timestamp(1495126825, 1), “t” : NumberLong(1), “h” : NumberLong(“7195178065440751511”), “v” : 2, “op” : “n”, “ns” : “”, “o” : {“msg” : “new primary”} }
{“ts” : Timestamp(1495126835, 1), “t” : NumberLong(1), “h” : NumberLong(“5723995478292318850”), “v” : 2, “op” : “n”, “ns” : “”, “o” : {“msg” : “periodic noop”} }
{“ts” : Timestamp(1495126845, 1), “t” : NumberLong(1), “h” : NumberLong(“-3772304067699003381”), “v” : 2, “op” : “n”, “ns” : “”, “o”

三、查看配置信息

rs0:PRIMARY> db.printReplicationInfo()
configured oplog size: 1024MB
log length start to end: 2541secs (0.71hrs)
oplog first event time: Fri May 19 2017 01:00:24 GMT+0800 (CST)
oplog last event time: Fri May 19 2017 01:42:45 GMT+0800 (CST)
now: Fri May 19 2017 01:42:48 GMT+0800 (CST)
rs0:PRIMARY>

db.oplog.rs.find()：查看复制集产生的日志
db.printReplicationInfo()：查看操作日志的一些基本信息，如日志大小、日志启用时间。
db.printSlaveReplicationInfo()：查看所有 slave 延迟情况。

rs0:PRIMARY> db.printSlaveReplicationInfo()
source: node2.pancou.com:27017
syncedTo: Fri May 19 2017 01:47:15 GMT+0800 (CST)
0 secs (0 hrs) behind the primary
source: node3.pancou.com:27017
syncedTo: Fri May 19 2017 01:47:15 GMT+0800 (CST)
0 secs (0 hrs) behind the primary

db.system.replset.find()：查看复制集

配置信息：

rs0:PRIMARY> db.system.replset.find()
{“_id” : “rs0”, “version” : 3, “protocolVersion” : NumberLong(1), “members” : [{ “_id” : 0, “host” : “node1.pancou.com:27017”, “arbiterOnly” : false, “buildIndexes” : true, “hidden” : false, “priority” : 1, “tags” : {}, “slaveDelay” : NumberLong(0), “votes” : 1 }, {“_id” : 1, “host” : “node2.pancou.com:27017”, “arbiterOnly” : false, “buildIndexes” : true, “hidden” : false, “priority” : 1, “tags” : {}, “slaveDelay” : NumberLong(0), “votes” : 1 }, {“_id” : 2, “host” : “node3.pancou.com: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” : 2000, “getLastErrorModes” : {}, “getLastErrorDefaults” : {“w” : 1, “wtimeout” : 0}, “replicaSetId” : ObjectId(“591dd3284fc6957e660dc933”) } }

rs0:PRIMARY> db.system.replset.find().forEach(printjson) 这种方式更直观

四、主从切换：

1、把 node3 冰冻 30 秒

rs0:SECONDARY> rs.freeze(30)
{“ok” : 1}

2、把 node1 PRIMARY 降级、
rs0:PRIMARY> rs.stepDown(30)
2017-05-19T02:09:27.945+0800 E QUERY [thread1] Error: error doing query: failed: network error while attempting to run command ‘replSetStepDown’ on host ‘127.0.0.1:27017’ :
DB.prototype.runCommand@src/mongo/shell/db.js:132:1
DB.prototype.adminCommand@src/mongo/shell/db.js:150:16
rs.stepDown@src/mongo/shell/utils.js:1261:12
@(shell):1:1
2017-05-19T02:09:27.947+0800 I NETWORK [thread1] trying reconnect to 127.0.0.1:27017 (127.0.0.1) failed
2017-05-19T02:09:27.949+0800 I NETWORK [thread1] reconnect 127.0.0.1:27017 (127.0.0.1) ok

30 秒后就变成从了
rs0:SECONDARY> rs.status()
{
“set” : “rs0”,
“date” : ISODate(“2017-05-18T18:12:09.732Z”),
“myState” : 2,
“term” : NumberLong(2),
“syncingTo” : “node2.pancou.com:27017”,
“heartbeatIntervalMillis” : NumberLong(2000),
“optimes” : {
“lastCommittedOpTime” : {
“ts” : Timestamp(1495131128, 1),
“t” : NumberLong(2)
},
“appliedOpTime” : {
“ts” : Timestamp(1495131128, 1),
“t” : NumberLong(2)
},
“durableOpTime” : {
“ts” : Timestamp(1495131128, 1),
“t” : NumberLong(2)
}
},
“members” : [
{
“_id” : 0,
“name” : “node1.pancou.com:27017”,
“health” : 1,
“state” : 2,
“stateStr” : “SECONDARY”,
“uptime” : 5519,
“optime” : {
“ts” : Timestamp(1495131128, 1),
“t” : NumberLong(2)
},
“optimeDate” : ISODate(“2017-05-18T18:12:08Z”),
“syncingTo” : “node2.pancou.com:27017”,
“configVersion” : 3,
“self” : true
},
{
“_id” : 1,
“name” : “node2.pancou.com:27017”,
“health” : 1,
“state” : 1,
“stateStr” : “PRIMARY”,
“uptime” : 3866,
“optime” : {
“ts” : Timestamp(1495131118, 1),
“t” : NumberLong(2)
},
“optimeDurable” : {
“ts” : Timestamp(1495131118, 1),
“t” : NumberLong(2)
},
“optimeDate” : ISODate(“2017-05-18T18:11:58Z”),
“optimeDurableDate” : ISODate(“2017-05-18T18:11:58Z”),
“lastHeartbeat” : ISODate(“2017-05-18T18:12:08.333Z”),
“lastHeartbeatRecv” : ISODate(“2017-05-18T18:12:08.196Z”),
“pingMs” : NumberLong(0),
“electionTime” : Timestamp(1495130977, 1),
“electionDate” : ISODate(“2017-05-18T18:09:37Z”),
“configVersion” : 3
},
{
“_id” : 2,
“name” : “node3.pancou.com:27017”,
“health” : 1,
“state” : 2,
“stateStr” : “SECONDARY”,
“uptime” : 3857,
“optime” : {
“ts” : Timestamp(1495131118, 1),
“t” : NumberLong(2)
},
“optimeDurable” : {
“ts” : Timestamp(1495131118, 1),
“t” : NumberLong(2)
},
“optimeDate” : ISODate(“2017-05-18T18:11:58Z”),
“optimeDurableDate” : ISODate(“2017-05-18T18:11:58Z”),
“lastHeartbeat” : ISODate(“2017-05-18T18:12:08.486Z”),
“lastHeartbeatRecv” : ISODate(“2017-05-18T18:12:08.116Z”),
“pingMs” : NumberLong(0),
“syncingTo” : “node2.pancou.com:27017”,
“configVersion” : 3
}
],
“ok” : 1
}
rs0:SECONDARY>

五、增减节点

1、增加节点

通过 oplog 增加节点，这种方式使数据的同步完全依赖于 oplog, 即 oplog 中有多少操作日志，这些操作日志就完全在新添加的节点中执行一遍，以完成同步。

在上面有一个 3 节点的复制集基础上，现在想配置并启动一个新节点，将其加入现在复制集环境中。

[root@node1 ~]# rsync -avH –progress ‘-e ssh -p 22’ /etc/hosts root@node2.pancou.com:/etc/

[root@node1 ~]# rsync -avH –progress ‘-e ssh -p 22’ /mongodb/mongokey root@node4.pancou.com:/mongodb/

[root@node1 ~]# rsync -avH –progress ‘-e ssh -p 22’ /etc/mongod.conf root@node4.pancou.com:/etc/

[root@node4 ~]# iptables -I INPUT 4 -m state –state NEW -p tcp –dport 27017 -j ACCEPT

在主上添加新节点：

rs0:PRIMARY> rs.add(“node4.pancou.com”)
{“ok” : 1}

rs0:PRIMARY> rs.status()
{
“set” : “rs0”,
“date” : ISODate(“2017-05-19T12:12:57.697Z”),
“myState” : 1,
“term” : NumberLong(8),
“heartbeatIntervalMillis” : NumberLong(2000),
“optimes” : {
“lastCommittedOpTime” : {
“ts” : Timestamp(1495195971, 1),
“t” : NumberLong(8)
},
“appliedOpTime” : {
“ts” : Timestamp(1495195971, 1),
“t” : NumberLong(8)
},
“durableOpTime” : {
“ts” : Timestamp(1495195971, 1),
“t” : NumberLong(8)
}
},
“members” : [
{
“_id” : 0,
“name” : “node1.pancou.com:27017”,
“health” : 1,
“state” : 2,
“stateStr” : “SECONDARY”,
“uptime” : 159,
“optime” : {
“ts” : Timestamp(1495195971, 1),
“t” : NumberLong(8)
},
“optimeDurable” : {
“ts” : Timestamp(1495195971, 1),
“t” : NumberLong(8)
},
“optimeDate” : ISODate(“2017-05-19T12:12:51Z”),
“optimeDurableDate” : ISODate(“2017-05-19T12:12:51Z”),
“lastHeartbeat” : ISODate(“2017-05-19T12:12:56.111Z”),
“lastHeartbeatRecv” : ISODate(“2017-05-19T12:12:57.101Z”),
“pingMs” : NumberLong(0),
“syncingTo” : “node3.pancou.com:27017”,
“configVersion” : 4
},
{
“_id” : 1,
“name” : “node2.pancou.com:27017”,
“health” : 1,
“state” : 2,
“stateStr” : “SECONDARY”,
“uptime” : 189,
“optime” : {
“ts” : Timestamp(1495195971, 1),
“t” : NumberLong(8)
},
“optimeDurable” : {
“ts” : Timestamp(1495195971, 1),
“t” : NumberLong(8)
},
“optimeDate” : ISODate(“2017-05-19T12:12:51Z”),
“optimeDurableDate” : ISODate(“2017-05-19T12:12:51Z”),
“lastHeartbeat” : ISODate(“2017-05-19T12:12:56.111Z”),
“lastHeartbeatRecv” : ISODate(“2017-05-19T12:12:57.103Z”),
“pingMs” : NumberLong(0),
“syncingTo” : “node3.pancou.com:27017”,
“configVersion” : 4
},
{
“_id” : 2,
“name” : “node3.pancou.com:27017”,
“health” : 1,
“state” : 1,
“stateStr” : “PRIMARY”,
“uptime” : 191,
“optime” : {
“ts” : Timestamp(1495195971, 1),
“t” : NumberLong(8)
},
“optimeDate” : ISODate(“2017-05-19T12:12:51Z”),
“electionTime” : Timestamp(1495195800, 1),
“electionDate” : ISODate(“2017-05-19T12:10:00Z”),
“configVersion” : 4,
“self” : true
},
{
“_id” : 3,
“name” : “node4.pancou.com:27017”,
“health” : 1,
“state” : 2,
“stateStr” : “SECONDARY”,
“uptime” : 71,
“optime” : {
“ts” : Timestamp(1495195971, 1),
“t” : NumberLong(8)
},
“optimeDurable” : {
“ts” : Timestamp(1495195971, 1),
“t” : NumberLong(8)
},
“optimeDate” : ISODate(“2017-05-19T12:12:51Z”),
“optimeDurableDate” : ISODate(“2017-05-19T12:12:51Z”),
“lastHeartbeat” : ISODate(“2017-05-19T12:12:56.122Z”),
“lastHeartbeatRecv” : ISODate(“2017-05-19T12:12:56.821Z”),
“pingMs” : NumberLong(1),
“syncingTo” : “node3.pancou.com:27017”,
“configVersion” : 4
}
],
“ok” : 1
}

查看状态：

rs0:SECONDARY> rs.slaveOk()
rs0:SECONDARY> show dbs
admin 0.000GB
local 0.000GB
testdb 0.000GB
rs0:SECONDARY> use testdb
switched to db testdb
rs0:SECONDARY> show collections
testcoll
rs0:SECONDARY> db.testcoll.find()
{“_id” : ObjectId(“591dd9f965cc255a5373aefa”), “name” : “tom”, “age” : 25 }
rs0:SECONDARY>
rs0:SECONDARY> db.isMaster()
{
“hosts” : [
“node1.pancou.com:27017”,
“node2.pancou.com:27017”,
“node3.pancou.com:27017”,
“node4.pancou.com:27017”
],
“setName” : “rs0”,
“setVersion” : 4,
“ismaster” : false,
“secondary” : true,
“primary” : “node3.pancou.com:27017”,
“me” : “node4.pancou.com:27017”,
“lastWrite” : {
“opTime” : {
“ts” : Timestamp(1495196261, 1),
“t” : NumberLong(8)
},
“lastWriteDate” : ISODate(“2017-05-19T12:17:41Z”)
},
“maxBsonObjectSize” : 16777216,
“maxMessageSizeBytes” : 48000000,
“maxWriteBatchSize” : 1000,
“localTime” : ISODate(“2017-05-19T12:17:44.104Z”),
“maxWireVersion” : 5,
“minWireVersion” : 0,
“readOnly” : false,
“ok” : 1
}
rs0:SECONDARY>

2、减少节点

rs0:PRIMARY> rs.remove(“node4.pancou.com:27017”)
{“ok” : 1}

rs0:PRIMARY> db.isMaster()
{
“hosts” : [
“node1.pancou.com:27017”,
“node2.pancou.com:27017”,
“node3.pancou.com:27017”
],
“setName” : “rs0”,
“setVersion” : 5,
“ismaster” : true,
“secondary” : false,
“primary” : “node3.pancou.com:27017”,
“me” : “node3.pancou.com:27017”,
“electionId” : ObjectId(“7fffffff0000000000000008”),
“lastWrite” : {
“opTime” : {
“ts” : Timestamp(1495196531, 1),
“t” : NumberLong(8)
},
“lastWriteDate” : ISODate(“2017-05-19T12:22:11Z”)
},
“maxBsonObjectSize” : 16777216,
“maxMessageSizeBytes” : 48000000,
“maxWriteBatchSize” : 1000,
“localTime” : ISODate(“2017-05-19T12:22:19.874Z”),
“maxWireVersion” : 5,
“minWireVersion” : 0,
“readOnly” : false,
“ok” : 1
}
rs0:PRIMARY>