MongoDB设置ReplicationSets

    MongoDB 高可用可用分两种 ：

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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。

                       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 >

chmod 400

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:

replication:

 replSetName:

Command Line

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

mongod --keyFile --replSet

    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>