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。

MongoDB设置 Replication Sets


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



一、MongoDB安装
    
 [[email protected] ~]# 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 


[[email protected] ~]# yum install -y mongodb-org


[[email protected] ~]# service mongod start
Starting mongod:                                           [  OK  ]
    
 [[email protected] ~]# 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:


[[email protected] ~]# mkdir -p /mongodb/data

[[email protected] ~]# chown -R mongod:mongod /mongodb/

[[email protected] ~]# ll /mongodb/
total 4
drwxr-xr-x 2 mongod mongod 4096 May 18 02:04 data


    
[[email protected] ~]# 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.


[[email protected] ~]# 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:


[[email protected] ~]# 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**文件的 Replication Sets:
    
 [[email protected] ~]# openssl rand -base64 756 > /mongodb/mongokey

 [[email protected] ~]# cat /mongodb/mongokey 

gxpcgjyFj2qE8b9TB/0XbdRVYH9VDb55NY03AHwxCFU58MUjJMeez844i1gaUo/t
.....
.....
  
 [[email protected] ~]# chmod 400 /mongodb/mongokey 

[[email protected] ~]# chown mongod:mongod /mongodb/mongokey 

[[email protected] ~]# 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


 [[email protected] ~]# vim /etc/mongod.conf
    #security:
security:
   keyFile: /mongodb/mongokey

#operationProfiling:

#replication:
replication:
   oplogSizeMB: 1024
   replSetName: rs0
    
    [[email protected] ~]# service mongod restart
Stopping mongod:                                           [  OK  ]
Starting mongod:                                           [  OK  ]
    
    [[email protected] ~]# iptables -I INPUT 4 -m state --state NEW -p tcp --dport 27017  -j ACCEPT
    
    复制hosts文件:
    [[email protected] ~]# rsync -avH --progress '-e ssh -p 22' /etc/hosts [email protected]:/mongodb/
    [[email protected] ~]# rsync -avH --progress '-e ssh -p 22' /etc/hosts [email protected]:/mongodb/

    复制**文件:
    [[email protected] ~]# rsync -avH --progress '-e ssh -p 22' /mongodb/mongokey [email protected]:/mongodb/
    [[email protected] ~]# rsync -avH --progress '-e ssh -p 22' /mongodb/mongokey [email protected]:/mongodb/
    
    复制配置文件:
    [[email protected] ~]# rsync -avH --progress '-e ssh -p 22' /etc/mongod.conf [email protected]:/etc/
    [[email protected] ~]# rsync -avH --progress '-e ssh -p 22' /etc/mongod.conf [email protected]:/etc/

    注意:双方都要按照rsync和openssh-clients


    [[email protected] ~]# 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'  :
[email protected]/mongo/shell/db.js:132:1
[email protected]/mongo/shell/db.js:150:16
[email protected]/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。
       

       [[email protected] ~]# rsync -avH --progress '-e ssh -p 22' /etc/hosts [email protected]:/etc/
       
       [[email protected] ~]# rsync -avH --progress '-e ssh -p 22' /mongodb/mongokey [email protected]:/mongodb/


       [[email protected] ~]# rsync -avH --progress '-e ssh -p 22' /etc/mongod.conf [email protected]:/etc/


       [[email protected] ~]# 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>