单机环境下MongoDB复制集测试步骤

素颜马尾好姑娘i 2022-08-07 13:42 133阅读 0赞

在自己的虚拟机环境中，对MongoDB复制集进行了测试，整个过程如下：

**MongoDB复制集简介**

MongoDB支持在多个机器中通过异步复制到达故障转移和实现冗余。多个机器中同一时刻只有一台用于写操作。正是由于这个情况，为MongoDB提供了数据一致性的保障。担当primary角色的机器能把读操作分发给slave。

MongoDB高可用分两种：

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和 -source参数，即可实现同步。这种方式与MySQL数据库的 master-slave复制方式非常类似，但MongoDB新版本已经不推荐此方案。

Replica Sets复制集：MongoDB在1.6版本的基础上开发了新功能replica set，这个功能更强大一些，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，大大降低了维护成本。auto shared已经明确说明不支持replication Paris，建议使用replica set故障切换完全自动。

replica sets的结构非常类似一个集群，和集群实现的作用是一样的，其中一个节点出现故障，其他节点马上回将业务接过来而无需停机操作。

复制集的架构如下：

![Image 1][]

**MongoDB复制集规划**

对于MongoDB的replica Sets复制集，也需要有一个规划：

replSet 复制集名称： rs1

MongoDB数据库安装安装路径为：/usr/local/mongodb/

复制集成员IP与端口：

节点1： localhost:28010   （默认的primary节点）

节点2： localhost:20811

节点3： localhost:28012

复制集各节点的数据文件，日志文件，私钥文件路径：

节点1： /data/data/r0  , /data/log/r0.log , /data/key/r0

节点2： /data/data/r1  , /data/log/r1.log , /data/key/r1

节点3： /data/data/r2  , /data/log/r2.log , /data/key/r2

**场景一：部署ReplicaSets**

**MongoDB的复制集配置步骤还是比较简单的，整体上说，就是准备好各个节点的数据文件、日志文件、私钥文件，然后带参数启动实例，配置replica set内容并初始化就可以了。**

**1） 创建数据文件存储路径**

mkdir -p /data02/mongors/data/r0

mkdir -p /data02/mongors/data/r1

mkdir -p /data02/mongors/data/r2

**2)创建日志文件路径**

mkdir -p /data02/mongors/log

**3)创建主从key文件**

用于标识集群的私钥的完整路径，如果各个实例的key file内容不一致，程序将不能正常使用

mkdir -p /data02/mongors/key

echo "this is rs1 super secret key" > /data02/mongors/key/r0

echo "this is rs1 super secret key" > /data02/mongors/key/r1

echo "this is rs1 super secret key" > /data02/mongors/key/r2

chmod 600 /data02/mongors/key/r\*

**4)启动3个实例**

依次添加启动参数，其中三个MongoDB实例：

/usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r0 --fork --port 28010 --dbpath /data02/mongors/data/r0 --logpath=/data02/mongors/log/r0.log --logappend

/usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r1 --fork --port 28011 --dbpath /data02/mongors/data/r1 --logpath=/data02/mongors/log/r1.log --logappend

/usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r2 --fork --port 28012 --dbpath /data02/mongors/data/r2 --logpath=/data02/mongors/log/r2.log --logappend

注：启动命令的参数分别为，mongod为主启动命令， replSet指定复制集名称为rs1，keyfile指定公钥文件 ，fork指定启动方式为deamo后台启动；port指定端口号，dbpath指定数据文件目录，logpath指定日志文件，logappend指定错误日志为日志追加模式；

实例启动过程如下：

#
    #/usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r0 --fork --port 28010 --dbpath /data02/mongors/data/r0 --logpath=/data02/mongors/log/r0.log --logappend
    about to fork child process, waiting until server is ready for connections.
    forked process: 10984
    child process started successfully, parent exiting
    #
    #/usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r1 --fork --port 28011 --dbpath /data02/mongors/data/r1 --logpath=/data02/mongors/log/r1.log --logappend
    about to fork child process, waiting until server is ready for connections.
    forked process: 11030
    child process started successfully, parent exiting
    #
    #/usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r2 --fork --port 28012 --dbpath /data02/mongors/data/r2 --logpath=/data02/mongors/log/r2.log --logappend
    about to fork child process, waiting until server is ready for connections.
    forked process: 11076
    child process started successfully, parent exiting
    #

通过进程和端口，验证启动状态：

ps -ef|grep mongo

netstat -tunlp | grep 28010

netstat -tunlp | grep 28011

netstat -tunlp | grep 28012

验证结果如下：

#ps -ef |grep mongo
    root      5715     1  0 Apr09 ?        00:11:50 mongod --dbpath=/data02/mongodb/db/ --logpath=/data02/mongodb/logs/mongodb.log --fork
    root     10984     1  0 14:23 ?        00:00:00 /usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r0 --fork --port 28010 --dbpath /data02/mongors/data/r0 --logpath=/data02/mongors/log/r0.log --logappend
    root     11030     1  0 14:23 ?        00:00:00 /usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r1 --fork --port 28011 --dbpath /data02/mongors/data/r1 --logpath=/data02/mongors/log/r1.log --logappend
    root     11076     1  0 14:23 ?        00:00:00 /usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r2 --fork --port 28012 --dbpath /data02/mongors/data/r2 --logpath=/data02/mongors/log/r2.log --logappend
    root     11121 10769  0 14:23 pts/1    00:00:00 grep mongo
    #
    #
    #netstat -tunlp |grep 28010
    tcp        0      0 0.0.0.0:28010               0.0.0.0:*                   LISTEN      10984/mongod        
    #
    #netstat -tunlp | grep 28011
    tcp        0      0 0.0.0.0:28011               0.0.0.0:*                   LISTEN      11030/mongod        
    #
    #netstat -tunlp | grep 28012
    tcp        0      0 0.0.0.0:28012               0.0.0.0:*                   LISTEN      11076/mongod        
    #

**5)配置及初始化 Replica Sets**

登录到primary服务器上：

\# /usr/local/mongo/bin/mongo -port 28010

配置复制集：

> config = \{\_id: 'rs1', members: \[

\{\_id: 0, host: 'localhost:28010',priority:1\},

\{\_id: 1, host: 'localhost:28011'\},

\{\_id: 2, host: 'localhost:28012'\}\]

"\_id" : "rs1",

"members": \[

"\_id": 0,

"host" : "localhost:28010"

\},

"\_id": 1,

"host" : "localhost:28011"

\},

"\_id": 2,

"host" : "localhost:28012"

初始化配置，使上面的配置生效：

>  rs.initiate(config);

实际操作过程如下：

#/usr/local/mongodb/bin/mongo -port 28010
    MongoDB shell version: 2.6.5
    connecting to: 127.0.0.1:28010/test
    > 
    > show databases;
    admin  (empty)
    local  0.078GB
    > 
    > show collections;
    2015-04-13T14:26:59.980+0800 error: { "$err" : "not master and slaveOk=false", "code" : 13435 } at src/mongo/shell/query.js:131
    > 
    > config = {_id: 'rs1', members: [
    ...                            {_id: 0, host: 'localhost:28010',priority:1},
    ...                            {_id: 1, host: 'localhost:28011'},
    ...                            {_id: 2, host: 'localhost:28012'}]
    ...             }
    {
            "_id" : "rs1",
            "members" : [
                    {
                            "_id" : 0,
                            "host" : "localhost:28010",
                            "priority" : 1
                    },
                    {
                            "_id" : 1,
                            "host" : "localhost:28011"
                    },
                    {
                            "_id" : 2,
                            "host" : "localhost:28012"
                    }
            ]
    }
    > 
    > rs.initiate(config);
    {
            "info" : "Config now saved locally.  Should come online in about a minute.",
            "ok" : 1
    }
    > 
    rs1:PRIMARY> 
    rs1:PRIMARY>

复制集配置并初始化完毕后，20810的前段自动产生了 rs1:PRIMARY 的标志。

**6)查看复制集状态**

> rs.status()

在primary节点上查看复制集状态：

> rs.isMaster()

实际查看结果如下：

rs1:PRIMARY> 
    rs1:PRIMARY> rs.status()
    {
            "set" : "rs1",
            "date" : ISODate("2015-04-13T06:40:12Z"),
            "myState" : 1,
            "members" : [
                    {
                            "_id" : 0,
                            "name" : "localhost:28010",
                            "health" : 1,
                            "state" : 1,
                            "stateStr" : "PRIMARY",
                            "uptime" : 1014,
                            "optime" : Timestamp(1428907084, 1),
                            "optimeDate" : ISODate("2015-04-13T06:38:04Z"),
                            "electionTime" : Timestamp(1428907094, 1),
                            "electionDate" : ISODate("2015-04-13T06:38:14Z"),
                            "self" : true
                    },
                    {
                            "_id" : 1,
                            "name" : "localhost:28011",
                            "health" : 1,
                            "state" : 2,
                            "stateStr" : "SECONDARY",
                            "uptime" : 126,
                            "optime" : Timestamp(1428907084, 1),
                            "optimeDate" : ISODate("2015-04-13T06:38:04Z"),
                            "lastHeartbeat" : ISODate("2015-04-13T06:40:10Z"),
                            "lastHeartbeatRecv" : ISODate("2015-04-13T06:40:11Z"),
                            "pingMs" : 0,
                            "syncingTo" : "localhost:28010"
                    },
                    {
                            "_id" : 2,
                            "name" : "localhost:28012",
                            "health" : 1,
                            "state" : 2,
                            "stateStr" : "SECONDARY",
                            "uptime" : 126,
                            "optime" : Timestamp(1428907084, 1),
                            "optimeDate" : ISODate("2015-04-13T06:38:04Z"),
                            "lastHeartbeat" : ISODate("2015-04-13T06:40:10Z"),
                            "lastHeartbeatRecv" : ISODate("2015-04-13T06:40:11Z"),
                            "pingMs" : 0,
                            "syncingTo" : "localhost:28010"
                    }
            ],
            "ok" : 1
    }
    rs1:PRIMARY> 
    rs1:PRIMARY> 
    rs1:PRIMARY> rs.isMaster()
    {
            "setName" : "rs1",
            "setVersion" : 1,
            "ismaster" : true,
            "secondary" : false,
            "hosts" : [
                    "localhost:28010",
                    "localhost:28012",
                    "localhost:28011"
            ],
            "primary" : "localhost:28010",
            "me" : "localhost:28010",
            "maxBsonObjectSize" : 16777216,
            "maxMessageSizeBytes" : 48000000,
            "maxWriteBatchSize" : 1000,
            "localTime" : ISODate("2015-04-13T06:40:52.024Z"),
            "maxWireVersion" : 2,
            "minWireVersion" : 0,
            "ok" : 1
    }
    rs1:PRIMARY> 
    rs1:PRIMARY>

通过这两个命令就可以确认复制集的节点状态和primary的状态，正常情况下，可以再primary节点进行各种添删改查等各种数据操作，其他非master节点不能进行各种数据操作，也不能发起复制集修改命令，如果进行命令操作，会提示如下错误：

rs1:SECONDARY> show collections;
    2015-04-13T14:42:58.431+0800 error: { "$err" : "not master and slaveOk=false", "code" : 13435 } at src/mongo/shell/query.js:131
    rs1:SECONDARY>

**场景二：查看主从操作日志oplog**

MongoDB的replica set架构是通过一个日志来存储写操作的，这个日志就叫做 oplog 。oplog.rs 是一个固定长度的 Capped Collection，它存在于local数据库中，用于记录replicaSets操作日志。在默认情况下，对于64位的MongoDB，oplog是比较大的，可以达到5%的磁盘空间，oplog的大小是可以通过mongod的参数 “ -oplogSize”来改变oplog的日志大小。

oplog内容样例：

> use local

> show collections

> db.oplog.rs.find()

查看master的oplog元数据信息：

> db.printReplicationInfo()

查看salve的同步状态：

> db.printSlaveReplicationInfo()

上面的命令执行结果如下：

#/usr/local/mongodb/bin/mongo -port 28010
    MongoDB shell version: 2.6.5
    connecting to: 127.0.0.1:28010/test
    rs1:PRIMARY> 
    rs1:PRIMARY> show databases;
    admin  (empty)
    local  1.078GB
    test   (empty)
    rs1:PRIMARY> 
    rs1:PRIMARY> use local
    switched to db local
    rs1:PRIMARY> 
    rs1:PRIMARY> show databases;
    admin  (empty)
    local  1.078GB
    test   (empty)
    rs1:PRIMARY> 
    rs1:PRIMARY> show collections;
    me
    oplog.rs
    slaves
    startup_log
    system.indexes
    system.replset
    rs1:PRIMARY> 
    rs1:PRIMARY> db.oplog.rs.find();
    { "ts" : Timestamp(1428907084, 1), "h" : NumberLong(0), "v" : 2, "op" : "n", "ns" : "", "o" : { "msg" : "initiating set" } }
    rs1:PRIMARY> 
    rs1:PRIMARY> db.printReplicationInfo();
    configured oplog size:   990MB
    log length start to end: 0secs (0hrs)
    oplog first event time:  Mon Apr 13 2015 14:38:04 GMT+0800 (CST)
    oplog last event time:   Mon Apr 13 2015 14:38:04 GMT+0800 (CST)
    now:                     Mon Apr 13 2015 14:46:44 GMT+0800 (CST)
    rs1:PRIMARY> 
    rs1:PRIMARY> db.printSlaveReplicationInfo();
    source: localhost:28011
            syncedTo: Mon Apr 13 2015 14:38:04 GMT+0800 (CST)
            0 secs (0 hrs) behind the primary 
    source: localhost:28012
            syncedTo: Mon Apr 13 2015 14:38:04 GMT+0800 (CST)
            0 secs (0 hrs) behind the primary 
    rs1:PRIMARY> 
    rs1:PRIMARY>

**场景三：主从配置信息查看与确认**

在local库中不仅有主从日志 oplog集合，还有一个集合用于记录主从配置信息 system.replset：

> use local

> show collections

> db.system.replset.find()

从这个集合中可以看出，Replica Sets的配置信息，也可以再任何已有成员实例上执行 rs.conf() 来查看信息。

rs1:PRIMARY> db
    local
    rs1:PRIMARY> 
    rs1:PRIMARY> show collections;
    me
    oplog.rs
    slaves
    startup_log
    system.indexes
    system.replset
    rs1:PRIMARY> 
    rs1:PRIMARY> db.system.replset.find();
    { "_id" : "rs1", "version" : 1, "members" : [ { "_id" : 0, "host" : "localhost:28010" }, { "_id" : 1, "host" : "localhost:28011" }, { "_id" : 2, "host" : "localhost:28012" } ] }
    rs1:PRIMARY> 
    rs1:PRIMARY> rs.conf();
    {
            "_id" : "rs1",
            "version" : 1,
            "members" : [
                    {
                            "_id" : 0,
                            "host" : "localhost:28010"
                    },
                    {
                            "_id" : 1,
                            "host" : "localhost:28011"
                    },
                    {
                            "_id" : 2,
                            "host" : "localhost:28012"
                    }
            ]
    }
    rs1:PRIMARY> 
    #/usr/local/mongodb/bin/mongo -port 28011
    MongoDB shell version: 2.6.5
    connecting to: 127.0.0.1:28011/test
    rs1:SECONDARY> 
    rs1:SECONDARY> 
    rs1:SECONDARY> db
    test
    rs1:SECONDARY> show collections;
    2015-04-13T14:51:32.097+0800 error: { "$err" : "not master and slaveOk=false", "code" : 13435 } at src/mongo/shell/query.js:131
    rs1:SECONDARY> 
    rs1:SECONDARY> rs.conf()
    {
            "_id" : "rs1",
            "version" : 1,
            "members" : [
                    {
                            "_id" : 0,
                            "host" : "localhost:28010"
                    },
                    {
                            "_id" : 1,
                            "host" : "localhost:28011"
                    },
                    {
                            "_id" : 2,
                            "host" : "localhost:28012"
                    }
            ]
    }
    rs1:SECONDARY> 
    rs1:SECONDARY> db.printSlaveReplicationInfo()
    source: localhost:28011
            syncedTo: Mon Apr 13 2015 14:50:54 GMT+0800 (CST)
            0 secs (0 hrs) behind the primary 
    source: localhost:28012
            syncedTo: Mon Apr 13 2015 14:50:54 GMT+0800 (CST)
            0 secs (0 hrs) behind the primary 
    rs1:SECONDARY>

**场景四：管理维护ReplicaSets实现读写分离和故障转移**

**读写分离实现步骤：**

有一些第三方工具，提供了一些可以让数据库进行读写分离的工具，如果从库能够进行查询就更好了，这样可以分担主库的大量的查询请求。

1） 先向主库中插入一条测试数据

\# ./mongo --port 28010

> db.c1.insert(\{age:30\});

> db.c1.find()

2)在从库进行查询等操作

\# ./mongo --port 28011

> show collections

当查询时报错了，说明是个从库，目前不能执行查询的操作。

3）让从库可以读，分担主库的压力

> db.getMongo().setSlaveOk()

> show collections

> db.c1.find

如果执行 db.getMongo().setSlaveOk() ，就可以将从库的查询功能打开。

整个测试过程如下：

#/usr/local/mongodb/bin/mongo -port 28010
    MongoDB shell version: 2.6.5
    connecting to: 127.0.0.1:28010/test
    rs1:PRIMARY> 
    rs1:PRIMARY> db
    test
    rs1:PRIMARY> show collections;
    rs1:PRIMARY> 
    rs1:PRIMARY> db.c1.insert({age:30});
    WriteResult({ "nInserted" : 1 })
    rs1:PRIMARY> 
    rs1:PRIMARY> show collections;
    c1
    system.indexes
    rs1:PRIMARY> 
    rs1:PRIMARY> db.c1.find();
    { "_id" : ObjectId("552b674ee7b1c3fc735c8316"), "age" : 30 }
    rs1:PRIMARY> 
    rs1:PRIMARY> quit();
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#/usr/local/mongodb/bin/mongo -port 28011
    MongoDB shell version: 2.6.5
    connecting to: 127.0.0.1:28011/test
    rs1:SECONDARY> 
    rs1:SECONDARY> 
    rs1:SECONDARY> db
    test
    rs1:SECONDARY> show collections;
    2015-04-13T14:51:32.097+0800 error: { "$err" : "not master and slaveOk=false", "code" : 13435 } at src/mongo/shell/query.js:131
    rs1:SECONDARY> 
    rs1:SECONDARY> rs.conf()
    {
            "_id" : "rs1",
            "version" : 1,
            "members" : [
                    {
                            "_id" : 0,
                            "host" : "localhost:28010"
                    },
                    {
                            "_id" : 1,
                            "host" : "localhost:28011"
                    },
                    {
                            "_id" : 2,
                            "host" : "localhost:28012"
                    }
            ]
    }
    rs1:SECONDARY> 
    rs1:SECONDARY> db.printSlaveReplicationInfo()
    source: localhost:28011
            syncedTo: Mon Apr 13 2015 14:50:54 GMT+0800 (CST)
            0 secs (0 hrs) behind the primary 
    source: localhost:28012
            syncedTo: Mon Apr 13 2015 14:50:54 GMT+0800 (CST)
            0 secs (0 hrs) behind the primary 
    rs1:SECONDARY> 
    rs1:SECONDARY> db.getMongo().setSlaveOk();
    rs1:SECONDARY> 
    rs1:SECONDARY> show collections;
    c1
    system.indexes
    rs1:SECONDARY> 
    rs1:SECONDARY> db.c1.find();
    { "_id" : ObjectId("552b674ee7b1c3fc735c8316"), "age" : 30 }
    rs1:SECONDARY> 
    rs1:SECONDARY> quit();
    #

**故障转移演示：**

复制集比传统的master-slave有改进的地方就是它可以进行故障的自动转移，如果我们停掉复制集中的一个成员，那么剩余的成员就会再自动选举一个成员，作为主库，如下所示。

我们将28010这个主库停掉，然后再看一下复制集的状态。

1） 杀掉28010端口的MongoDB

\# ps aux | grep mongod

\# kill -9 6706

2) 查看复制集状态

\# ./mongo --port 28011

> rs.status();

可以看到28010这个端口的MongoDB出现了异常，而系统自动选举了 28012 这个端口为主，所以这样的故障处理机制，能讲系统的稳定性大大提高。

测试过程如下：

#echo "kill primary to Fail over"
    kill primary to Fail over
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#ps -ef|grep mongo
    root      5715     1  0 Apr09 ?        00:11:55 mongod --dbpath=/data02/mongodb/db/ --logpath=/data02/mongodb/logs/mongodb.log --fork
    root     10984     1  0 14:23 ?        00:00:06 /usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r0 --fork --port 28010 --dbpath /data02/mongors/data/r0 --logpath=/data02/mongors/log/r0.log --logappend
    root     11030     1  0 14:23 ?        00:00:05 /usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r1 --fork --port 28011 --dbpath /data02/mongors/data/r1 --logpath=/data02/mongors/log/r1.log --logappend
    root     11076     1  0 14:23 ?        00:00:05 /usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r2 --fork --port 28012 --dbpath /data02/mongors/data/r2 --logpath=/data02/mongors/log/r2.log --logappend
    root     11731     1  0 14:58 ?        00:00:01 /usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r3 --fork --port 28013 --dbpath /data02/mongors/data/r3 --logpath=/data02/mongors/log/r3.log --logappend
    root     12186 10769  0 15:05 pts/1    00:00:00 grep mongo
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#/usr/local/mongodb/bin/mongo -port 28010
    MongoDB shell version: 2.6.5
    connecting to: 127.0.0.1:28010/test
    rs1:PRIMARY> 
    rs1:PRIMARY> rs.isMaster();
    {
            "setName" : "rs1",
            "setVersion" : 2,
            "ismaster" : true,
            "secondary" : false,
            "hosts" : [
                    "localhost:28010",
                    "localhost:28013",
                    "localhost:28012",
                    "localhost:28011"
            ],
            "primary" : "localhost:28010",
            "me" : "localhost:28010",
            "maxBsonObjectSize" : 16777216,
            "maxMessageSizeBytes" : 48000000,
            "maxWriteBatchSize" : 1000,
            "localTime" : ISODate("2015-04-13T07:06:06.185Z"),
            "maxWireVersion" : 2,
            "minWireVersion" : 0,
            "ok" : 1
    }
    rs1:PRIMARY> 
    rs1:PRIMARY> quit();
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#ps -ef|grep mongod
    root      5715     1  0 Apr09 ?        00:11:55 mongod --dbpath=/data02/mongodb/db/ --logpath=/data02/mongodb/logs/mongodb.log --fork
    root     10984     1  0 14:23 ?        00:00:06 /usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r0 --fork --port 28010 --dbpath /data02/mongors/data/r0 --logpath=/data02/mongors/log/r0.log --logappend
    root     11030     1  0 14:23 ?        00:00:06 /usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r1 --fork --port 28011 --dbpath /data02/mongors/data/r1 --logpath=/data02/mongors/log/r1.log --logappend
    root     11076     1  0 14:23 ?        00:00:06 /usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r2 --fork --port 28012 --dbpath /data02/mongors/data/r2 --logpath=/data02/mongors/log/r2.log --logappend
    root     11731     1  0 14:58 ?        00:00:01 /usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r3 --fork --port 28013 --dbpath /data02/mongors/data/r3 --logpath=/data02/mongors/log/r3.log --logappend
    root     12237 10769  0 15:06 pts/1    00:00:00 grep mongod
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#ps aux |grep mongod
    root      5715  0.2  2.1 1660908 41588 ?       Sl   Apr09  11:55 mongod --dbpath=/data02/mongodb/db/ --logpath=/data02/mongodb/logs/mongodb.log --fork
    root     10984  0.2  2.1 2703968 41512 ?       Sl   14:23   0:06 /usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r0 --fork --port 28010 --dbpath /data02/mongors/data/r0 --logpath=/data02/mongors/log/r0.log --logappend
    root     11030  0.2  1.9 2683292 36708 ?       Sl   14:23   0:06 /usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r1 --fork --port 28011 --dbpath /data02/mongors/data/r1 --logpath=/data02/mongors/log/r1.log --logappend
    root     11076  0.2  1.9 2683288 36668 ?       Sl   14:23   0:06 /usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r2 --fork --port 28012 --dbpath /data02/mongors/data/r2 --logpath=/data02/mongors/log/r2.log --logappend
    root     11731  0.2  1.9 2684316 37188 ?       Sl   14:58   0:01 /usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r3 --fork --port 28013 --dbpath /data02/mongors/data/r3 --logpath=/data02/mongors/log/r3.log --logappend
    root     12245  0.0  0.0 103252   832 pts/1    S+   15:06   0:00 grep mongod
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#kill -9 10984
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#ps -ef|grep mongod 
    root      5715     1  0 Apr09 ?        00:11:55 mongod --dbpath=/data02/mongodb/db/ --logpath=/data02/mongodb/logs/mongodb.log --fork
    root     11030     1  0 14:23 ?        00:00:06 /usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r1 --fork --port 28011 --dbpath /data02/mongors/data/r1 --logpath=/data02/mongors/log/r1.log --logappend
    root     11076     1  0 14:23 ?        00:00:06 /usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r2 --fork --port 28012 --dbpath /data02/mongors/data/r2 --logpath=/data02/mongors/log/r2.log --logappend
    root     11731     1  0 14:58 ?        00:00:01 /usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r3 --fork --port 28013 --dbpath /data02/mongors/data/r3 --logpath=/data02/mongors/log/r3.log --logappend
    root     12289 10769  0 15:07 pts/1    00:00:00 grep mongod
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#/usr/local/mongodb/bin/mongo -port 28013
    MongoDB shell version: 2.6.5
    connecting to: 127.0.0.1:28013/test
    rs1:SECONDARY> 
    rs1:SECONDARY> rs.status();
    {
            "set" : "rs1",
            "date" : ISODate("2015-04-13T07:07:41Z"),
            "myState" : 2,
            "syncingTo" : "localhost:28011",
            "members" : [
                    {
                            "_id" : 0,
                            "name" : "localhost:28010",
                            "health" : 0,
                            "state" : 8,
                            "stateStr" : "(not reachable/healthy)",
                            "uptime" : 0,
                            "optime" : Timestamp(1428908577, 1),
                            "optimeDate" : ISODate("2015-04-13T07:02:57Z"),
                            "lastHeartbeat" : ISODate("2015-04-13T07:07:40Z"),
                            "lastHeartbeatRecv" : ISODate("2015-04-13T07:07:12Z"),
                            "pingMs" : 0
                    },
                    {
                            "_id" : 1,
                            "name" : "localhost:28011",
                            "health" : 1,
                            "state" : 1,
                            "stateStr" : "PRIMARY",
                            "uptime" : 462,
                            "optime" : Timestamp(1428908577, 1),
                            "optimeDate" : ISODate("2015-04-13T07:02:57Z"),
                            "lastHeartbeat" : ISODate("2015-04-13T07:07:39Z"),
                            "lastHeartbeatRecv" : ISODate("2015-04-13T07:07:39Z"),
                            "pingMs" : 0,
                            "electionTime" : Timestamp(1428908838, 1),
                            "electionDate" : ISODate("2015-04-13T07:07:18Z")
                    },
                    {
                            "_id" : 2,
                            "name" : "localhost:28012",
                            "health" : 1,
                            "state" : 2,
                            "stateStr" : "SECONDARY",
                            "uptime" : 462,
                            "optime" : Timestamp(1428908577, 1),
                            "optimeDate" : ISODate("2015-04-13T07:02:57Z"),
                            "lastHeartbeat" : ISODate("2015-04-13T07:07:39Z"),
                            "lastHeartbeatRecv" : ISODate("2015-04-13T07:07:39Z"),
                            "pingMs" : 0,
                            "lastHeartbeatMessage" : "syncing to: localhost:28011",
                            "syncingTo" : "localhost:28011"
                    },
                    {
                            "_id" : 3,
                            "name" : "localhost:28013",
                            "health" : 1,
                            "state" : 2,
                            "stateStr" : "SECONDARY",
                            "uptime" : 578,
                            "optime" : Timestamp(1428908577, 1),
                            "optimeDate" : ISODate("2015-04-13T07:02:57Z"),
                            "infoMessage" : "syncing to: localhost:28011",
                            "self" : true
                    }
            ],
            "ok" : 1
    }
    rs1:SECONDARY> 
    rs1:SECONDARY> 
    rs1:SECONDARY> quit();
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#/usr/local/mongodb/bin/mongo -port 28011
    MongoDB shell version: 2.6.5
    connecting to: 127.0.0.1:28011/test
    rs1:PRIMARY> 
    rs1:PRIMARY> db
    test
    rs1:PRIMARY> 
    rs1:PRIMARY> show collections;
    c1
    system.indexes
    rs1:PRIMARY> 
    rs1:PRIMARY> db.c1.find();
    { "_id" : ObjectId("552b674ee7b1c3fc735c8316"), "age" : 30 }
    { "_id" : ObjectId("552b6a21572fc5a02732f62c"), "age" : 40 }
    rs1:PRIMARY> 
    rs1:PRIMARY> db.c1.insert({age:50});
    WriteResult({ "nInserted" : 1 })
    rs1:PRIMARY> 
    rs1:PRIMARY> db.c1.find();
    { "_id" : ObjectId("552b674ee7b1c3fc735c8316"), "age" : 30 }
    { "_id" : ObjectId("552b6a21572fc5a02732f62c"), "age" : 40 }
    { "_id" : ObjectId("552b6ba3cb6fc10cc6fc9085"), "age" : 50 }
    rs1:PRIMARY> 
    rs1:PRIMARY> rs.conf();
    {
            "_id" : "rs1",
            "version" : 2,
            "members" : [
                    {
                            "_id" : 0,
                            "host" : "localhost:28010"
                    },
                    {
                            "_id" : 1,
                            "host" : "localhost:28011"
                    },
                    {
                            "_id" : 2,
                            "host" : "localhost:28012"
                    },
                    {
                            "_id" : 3,
                            "host" : "localhost:28013"
                    }
            ]
    }
    rs1:PRIMARY> 
    rs1:PRIMARY> db.printSlaveReplicationInfo()
    source: localhost:28010
            syncedTo: Mon Apr 13 2015 15:02:57 GMT+0800 (CST)
            386 secs (0.11 hrs) behind the primary 
    source: localhost:28012
            syncedTo: Mon Apr 13 2015 15:09:23 GMT+0800 (CST)
            0 secs (0 hrs) behind the primary 
    source: localhost:28013
            syncedTo: Mon Apr 13 2015 15:09:23 GMT+0800 (CST)
            0 secs (0 hrs) behind the primary 
    rs1:PRIMARY> 
    rs1:PRIMARY> quit()
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#/usr/local/mongodb/bin/mongo -port 28013
    MongoDB shell version: 2.6.5
    connecting to: 127.0.0.1:28013/test
    rs1:SECONDARY> 
    rs1:SECONDARY> 
    rs1:SECONDARY> db
    test
    rs1:SECONDARY> 
    rs1:SECONDARY> show collections;
    2015-04-13T15:11:12.092+0800 error: { "$err" : "not master and slaveOk=false", "code" : 13435 } at src/mongo/shell/query.js:131
    rs1:SECONDARY> 
    rs1:SECONDARY> db.getMongo().setSlaveOk();
    rs1:SECONDARY> 
    rs1:SECONDARY> show collections;
    c1
    system.indexes
    rs1:SECONDARY> 
    rs1:SECONDARY> db.c1.find();
    { "_id" : ObjectId("552b674ee7b1c3fc735c8316"), "age" : 30 }
    { "_id" : ObjectId("552b6a21572fc5a02732f62c"), "age" : 40 }
    { "_id" : ObjectId("552b6ba3cb6fc10cc6fc9085"), "age" : 50 }
    rs1:SECONDARY> 
    rs1:SECONDARY> 
    rs1:SECONDARY> quit()
    [root@MySQL193 /data02]#

注意：故障转移以后，即使坏了的节点再次修好，复制集的primary也不会再自动漂移。

**场景五：增加和减少复制集中的节点**

MongoDB Replica Sets不仅提供高可用性的解决方案，同时也提供负载均衡的解决方案，增减 Replica Sets节点在实际应用中非常普通。例如，当应用的读压力暴增时，3台节点的环境已不能满足需求，那么就需要增加一些节点将压力平均分配一下；当应用的压力小时，可以减少一些节点来减少硬件资源的成本，总之这是一个长期且持续的工作。

**增加节点步骤**

1） 配置并启动新节点，启用 28013 这个端口给新的节点

mkdir -p /data02/mongors/data/r3

echo " this is rs1 super secret key " > /data02/mongors/key/r3

chmod 600 /data02/mongors/key/r3

/usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r3 --fork --port 28013 --dbpath /data02/mongors/data/r3 --logpath=/data02/mongors/log/r3.log --logappend

2) 在primary节点上执行命令添加此新节点到现有的 Replica Sets

> rs.add("localhost:28013");

3）查看Replica Sets的状态，可以清晰地看到内部添加28013这个新节点的几个过程

> rs.stats

步骤一：进行初始化

步骤二：进行数据同步

步骤三：初始化同步完成

步骤四：节点添加完成，状态正常

4）验证数据已经同步过来了

\# /usr/local/bin/mongo/bin/mongo -port 28013

> rs.slaveOK()

> db.c1.find()

实验过程如下：

#echo " add a new host into rs1"
     add a new host into rs1
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#pwd
    /data02
    [root@MySQL193 /data02]#ll
    total 12
    drwxr-xr-x 4 root  root  4096 Apr  9 14:09 mongodb
    drwxr-xr-x 5 root  root  4096 Apr 13 14:20 mongors
    drwxr-xr-x 3 mysql mysql 4096 Apr  9 17:45 mysqldata
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#mkdir -p /data02/mongors/data/r3
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#echo " this is rs1 super secret key " > /data02/mongors/key/r3
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#chmod 600 /data02/mongors/key/r3
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#/usr/local/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r3 --fork --port 28013 --dpath /data02/mongors/data/r3 --logpath=/data02/mongors/log/r3.log --logappend
    -bash: /usr/local/bin/mongod: No such file or directory
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#/usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r3 --fork --port 28013 --dpath /data02/mongors/data/r3 --logpath=/data02/mongors/log/r3.log --logappend
    Error parsing command line: unknown option dpath
    try '/usr/local/mongodb/bin/mongod --help' for more information
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#/usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r3 --fork --port 28013 --dbpath /data02/mongors/data/r3 --logpath=/data02/mongors/log/r3.log --logappend
    about to fork child process, waiting until server is ready for connections.
    forked process: 11731
    child process started successfully, parent exiting
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#ps -ef|grep mongo
    root      5715     1  0 Apr09 ?        00:11:54 mongod --dbpath=/data02/mongodb/db/ --logpath=/data02/mongodb/logs/mongodb.log --fork
    root     10984     1  0 14:23 ?        00:00:05 /usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r0 --fork --port 28010 --dbpath /data02/mongors/data/r0 --logpath=/data02/mongors/log/r0.log --logappend
    root     11030     1  0 14:23 ?        00:00:04 /usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r1 --fork --port 28011 --dbpath /data02/mongors/data/r1 --logpath=/data02/mongors/log/r1.log --logappend
    root     11076     1  0 14:23 ?        00:00:04 /usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r2 --fork --port 28012 --dbpath /data02/mongors/data/r2 --logpath=/data02/mongors/log/r2.log --logappend
    root     11731     1  0 14:58 ?        00:00:00 /usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r3 --fork --port 28013 --dbpath /data02/mongors/data/r3 --logpath=/data02/mongors/log/r3.log --logappend
    root     11782 10769  0 14:58 pts/1    00:00:00 grep mongo
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#/usr/local/mongodb/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r3 --fork --port 28013 --dbpath /data02/mongors/data/r3 --logpata02/mongors/key/r3 --fork --port 28013 --dpath /data02/mongors/data/r3 --logpa[root@MySQL193 /data02]#/usr/local/bin/mongod --replSet rs1 --keyFile /data02/mongors/key/r3 --fork --port 28013 --dpath /data02/mongors/data/r3 --logpath=/data[root@MySQL193 /data02]#chmod 600 /data02/mongors/key/r3                        
    [root@MySQL193 /data02]#echo " this is rs1 super secret key " > /data02/mongors/[root@MySQL193 /data02]#mkdir -p /data02/mongors/data/r3                        [root@MySQL193 /data02]#/usr/local/mongodb/bin/mongo -port 28013
    MongoDB shell version: 2.6.5
    connecting to: 127.0.0.1:28013/test
    > 
    > 
    > rs.status();
    {
            "startupStatus" : 3,
            "info" : "run rs.initiate(...) if not yet done for the set",
            "ok" : 0,
            "errmsg" : "can't get local.system.replset config from self or any seed (EMPTYCONFIG)"
    }
    > 
    > rs.add("localhost:28013");
    assert failed : no config object retrievable from local.system.replset
    Error: assert failed : no config object retrievable from local.system.replset
        at Error (<anonymous>)
        at doassert (src/mongo/shell/assert.js:11:14)
        at assert (src/mongo/shell/assert.js:20:5)
        at Function.rs.add (src/mongo/shell/utils.js:979:5)
        at (shell):1:4
    2015-04-13T14:59:13.271+0800 Error: assert failed : no config object retrievable from local.system.replset at src/mongo/shell/assert.js:13
    > 
    > quit();
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#
    [root@MySQL193 /data02]#/usr/local/mongodb/bin/mongo -port 28010
    MongoDB shell version: 2.6.5
    connecting to: 127.0.0.1:28010/test
    rs1:PRIMARY> 
    rs1:PRIMARY> 
    rs1:PRIMARY> rs.status();
    {
            "set" : "rs1",
            "date" : ISODate("2015-04-13T06:59:34Z"),
            "myState" : 1,
            "members" : [
                    {
                            "_id" : 0,
                            "name" : "localhost:28010",
                            "health" : 1,
                            "state" : 1,
                            "stateStr" : "PRIMARY",
                            "uptime" : 2176,
                            "optime" : Timestamp(1428907854, 1),
                            "optimeDate" : ISODate("2015-04-13T06:50:54Z"),
                            "electionTime" : Timestamp(1428907094, 1),
                            "electionDate" : ISODate("2015-04-13T06:38:14Z"),
                            "self" : true
                    },
                    {
                            "_id" : 1,
                            "name" : "localhost:28011",
                            "health" : 1,
                            "state" : 2,
                            "stateStr" : "SECONDARY",
                            "uptime" : 1288,
                            "optime" : Timestamp(1428907854, 1),
                            "optimeDate" : ISODate("2015-04-13T06:50:54Z"),
                            "lastHeartbeat" : ISODate("2015-04-13T06:59:33Z"),
                            "lastHeartbeatRecv" : ISODate("2015-04-13T06:59:33Z"),
                            "pingMs" : 0,
                            "syncingTo" : "localhost:28010"
                    },
                    {
                            "_id" : 2,
                            "name" : "localhost:28012",
                            "health" : 1,
                            "state" : 2,
                            "stateStr" : "SECONDARY",
                            "uptime" : 1288,
                            "optime" : Timestamp(1428907854, 1),
                            "optimeDate" : ISODate("2015-04-13T06:50:54Z"),
                            "lastHeartbeat" : ISODate("2015-04-13T06:59:33Z"),
                            "lastHeartbeatRecv" : ISODate("2015-04-13T06:59:33Z"),
                            "pingMs" : 0,
                            "syncingTo" : "localhost:28010"
                    }
            ],
            "ok" : 1
    }
    rs1:PRIMARY> 
    rs1:PRIMARY> rs.add("localhost:28013");
    { "ok" : 1 }
    rs1:PRIMARY> 
    rs1:PRIMARY> rs.status();
    {
            "set" : "rs1",
            "date" : ISODate("2015-04-13T06:59:59Z"),
            "myState" : 1,
            "members" : [
                    {
                            "_id" : 0,
                            "name" : "localhost:28010",
                            "health" : 1,
                            "state" : 1,
                            "stateStr" : "PRIMARY",
                            "uptime" : 2201,
                            "optime" : Timestamp(1428908396, 1),
                            "optimeDate" : ISODate("2015-04-13T06:59:56Z"),
                            "electionTime" : Timestamp(1428907094, 1),
                            "electionDate" : ISODate("2015-04-13T06:38:14Z"),
                            "self" : true
                    },
                    {
                            "_id" : 1,
                            "name" : "localhost:28011",
                            "health" : 1,
                            "state" : 2,
                            "stateStr" : "SECONDARY",
                            "uptime" : 1313,
                            "optime" : Timestamp(1428908396, 1),
                            "optimeDate" : ISODate("2015-04-13T06:59:56Z"),
                            "lastHeartbeat" : ISODate("2015-04-13T06:59:59Z"),
                            "lastHeartbeatRecv" : ISODate("2015-04-13T06:59:57Z"),
                            "pingMs" : 0,
                            "syncingTo" : "localhost:28010"
                    },
                    {
                            "_id" : 2,
                            "name" : "localhost:28012",
                            "health" : 1,
                            "state" : 2,
                            "stateStr" : "SECONDARY",
                            "uptime" : 1313,
                            "optime" : Timestamp(1428908396, 1),
                            "optimeDate" : ISODate("2015-04-13T06:59:56Z"),
                            "lastHeartbeat" : ISODate("2015-04-13T06:59:59Z"),
                            "lastHeartbeatRecv" : ISODate("2015-04-13T06:59:59Z"),
                            "pingMs" : 0,
                            "syncingTo" : "localhost:28010"
                    },
                    {
                            "_id" : 3,
                            "name" : "localhost:28013",
                            "health" : 1,
                            "state" : 5,
                            "stateStr" : "STARTUP2",
                            "uptime" : 3,
                            "optime" : Timestamp(0, 0),
                            "optimeDate" : ISODate("1970-01-01T00:00:00Z"),
                            "lastHeartbeat" : ISODate("2015-04-13T06:59:58Z"),
                            "lastHeartbeatRecv" : ISODate("1970-01-01T00:00:00Z"),
                            "pingMs" : 0,
                            "lastHeartbeatMessage" : "initial sync need a member to be primary or secondary to do our initial sync"
                    }
            ],
            "ok" : 1
    }
    rs1:PRIMARY>

**删除节点步骤**

下面将刚刚添加的两个新节点 28013 从复制集中去除掉，只需只需 rs.remove 指令就可以了，具体如下：

登录到primary 节点，执行下面的命令将28013 从复制集中去掉：

> rs.remove("localhsots:28013");

查看复制集状态，可以看到只有三个成员，原来的两个成员都已经成功去除了：

> rs.status()

实验过程如下：

#/usr/local/mongodb/bin/mongo -port 28011
    MongoDB shell version: 2.6.5
    connecting to: 127.0.0.1:28011/test
    rs1:PRIMARY> 
    rs1:PRIMARY> rs.conf()
    {
            "_id" : "rs1",
            "version" : 2,
            "members" : [
                    {
                            "_id" : 0,
                            "host" : "localhost:28010"
                    },
                    {
                            "_id" : 1,
                            "host" : "localhost:28011"
                    },
                    {
                            "_id" : 2,
                            "host" : "localhost:28012"
                    },
                    {
                            "_id" : 3,
                            "host" : "localhost:28013"
                    }
            ]
    }
    rs1:PRIMARY> 
    rs1:PRIMARY> rs.remove("localhost:28013");
    2015-04-13T15:24:52.181+0800 DBClientCursor::init call() failed
    2015-04-13T15:24:52.182+0800 Error: error doing query: failed at src/mongo/shell/query.js:81
    2015-04-13T15:24:52.183+0800 trying reconnect to 127.0.0.1:28011 (127.0.0.1) failed
    2015-04-13T15:24:52.184+0800 reconnect 127.0.0.1:28011 (127.0.0.1) ok
    rs1:PRIMARY> 
    rs1:PRIMARY> rs.conf()
    {
            "_id" : "rs1",
            "version" : 3,
            "members" : [
                    {
                            "_id" : 0,
                            "host" : "localhost:28010"
                    },
                    {
                            "_id" : 1,
                            "host" : "localhost:28011"
                    },
                    {
                            "_id" : 2,
                            "host" : "localhost:28012"
                    }
            ]
    }
    rs1:PRIMARY> 
    rs1:PRIMARY> rs.status()
    {
            "set" : "rs1",
            "date" : ISODate("2015-04-13T07:25:15Z"),
            "myState" : 1,
            "members" : [
                    {
                            "_id" : 0,
                            "name" : "localhost:28010",
                            "health" : 1,
                            "state" : 2,
                            "stateStr" : "SECONDARY",
                            "uptime" : 23,
                            "optime" : Timestamp(1428909892, 1),
                            "optimeDate" : ISODate("2015-04-13T07:24:52Z"),
                            "lastHeartbeat" : ISODate("2015-04-13T07:25:14Z"),
                            "lastHeartbeatRecv" : ISODate("2015-04-13T07:25:14Z"),
                            "pingMs" : 0,
                            "lastHeartbeatMessage" : "syncing to: localhost:28011",
                            "syncingTo" : "localhost:28011"
                    },
                    {
                            "_id" : 1,
                            "name" : "localhost:28011",
                            "health" : 1,
                            "state" : 1,
                            "stateStr" : "PRIMARY",
                            "uptime" : 3699,
                            "optime" : Timestamp(1428909892, 1),
                            "optimeDate" : ISODate("2015-04-13T07:24:52Z"),
                            "electionTime" : Timestamp(1428908838, 1),
                            "electionDate" : ISODate("2015-04-13T07:07:18Z"),
                            "self" : true
                    },
                    {
                            "_id" : 2,
                            "name" : "localhost:28012",
                            "health" : 1,
                            "state" : 2,
                            "stateStr" : "SECONDARY",
                            "uptime" : 23,
                            "optime" : Timestamp(1428909892, 1),
                            "optimeDate" : ISODate("2015-04-13T07:24:52Z"),
                            "lastHeartbeat" : ISODate("2015-04-13T07:25:14Z"),
                            "lastHeartbeatRecv" : ISODate("2015-04-13T07:25:15Z"),
                            "pingMs" : 0,
                            "lastHeartbeatMessage" : "syncing to: localhost:28011",
                            "syncingTo" : "localhost:28011"
                    }
            ],
            "ok" : 1
    }
    rs1:PRIMARY> 
    rs1:PRIMARY> 
    rs1:PRIMARY> 
    rs1:PRIMARY> quit()

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