MongoDB设置 Replication Sets

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。


​
​
192.168.110.131(node1)
192.168.110.132(node2)
192.168.110.133(node3)
​


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>