mongodb之replSet复制集
复制集是一个带有故障转移的主从集群。是从现有的主从模式演变而来，增加了自动故障转移和节点成员自动恢复。
复制集模式中没有固定的主结点，在启动后，多个服务节点间将自动选举产生一个主结点。该主结点被称为primary，一个或多个从结点被称为secondaries。primary结点基本上就是master结点，不同之处在于primary结点在不同时间可能是不同的服务器。如果当前的主结点失效了，复制集中的其余结点将会试图选出一个新的主结点。
复制集模式的好处是，一切自动化。首先，复制集模式本身做了大量的管理工作，自动管理从节点，确保数据不会不一致。其次，主节点挂掉后，会自动判断集群中的服务器并进行故障转移，推举新的主节点。一个复制集集群支持1-7台服务器，在一个复制集中各个服务器数据保持完全一致。
在一个复制集集群中，各个服务器有以下几种状态：
Primary 主节点，一个复制集有且仅有一台服务器处于Primary状态，只有主节点才对外提供读写服务。如果主节点挂掉，复制集将会投票选出一个备用节点成为新的主节点。
Secondary 备用节点，复制集允许有多台Secondary，每个备用节点的数据与主节点的数据是完全同步的。
Recovering 恢复中，当复制集中某台服务器挂掉或者掉线后数据无法同步，重新恢复服务后从其他成员复制数据，这时就处于恢复过程，数据同步后，该节点又回到备用状态。
Arbiter 仲裁节点，该类节点可以不用单独存在，如果配置为仲裁节点，就主要负责在复本集中监控其他节点状态，投票选出主节点。该节点将不会用于存放数据。如果没有仲裁节点，那么投票工作将由所有节点共同进行。
Down 无效节点，当服务器挂掉或掉线时就会处于该状态。
复制集的从节点读请求，也是在各个Driver层设置slaveOk的值来实现的。
操作系统环境如下：
OS：Centos6.4 64bit IP：192.168.33.131
此次操作均在同一台机器上操作，安装mongodb请参考mongodb2.6安装编，然后建立复制集相对应的目录以及log日志文件等等
1：目录规划如下：
[root@localhost opt]# pwd /opt [root@localhost opt]# tree . . ├── logs ├── rs0 ├── rs1 └── rs2 4 directories, 0 files
2：因为在此服务器上需要配置replSet复制集，所以不使用默认的配置文件以及服务，需要但对建立配置文件以及更改相应的，目录文件日志文件等等
mongod对应ip地址以及端口如下：
mongod-IP Port 192.168.33.131 30000//主 192.168.33.131 30001//从 192.168.33.131 30002//从
3：mongodb各个配置文件如下：
mongodb-30000配置文件
# grep '^[a-Z]' /etc/30000.conf
logpath=/opt/log/rs0.log #日志文件
logappend=true #日志以追加模式
fork = true #后台启动
port = 30000#端口号
dbpath=/opt/rs0#mongodb数据目录
pidfilepath = /opt/rs0/30000.pid#mongodb-pid
master = true #是否参加选举
replSet = zxl#复制集名称
rest = true#mongodb接口，web界面访问
mongodb-30001配置文件
# grep '^[a-Z]' /etc/30001.conf
logpath=/opt/log/rs1.log
logappend=true
fork = true
port = 30001
dbpath=/opt/rs1
pidfilepath = /opt/rs1/30001.pid
master = true
replSet = zxl
mongodb-30002配置文件
# grep '^[a-Z]' /etc/30002.conf
logpath=/opt/log/rs2.log
logappend=true
fork = true
port = 30002
dbpath=/opt/rs2
pidfilepath = /opt/rs2/30002.pid
master = true
replSet = zxl
4：启动各个mongodb节点，方式如下：
mongodb端口30000启动
# mongod -f /etc/30000.conf about to fork child process, waiting until server is ready for connections. forked process: 1968 all output going to: /opt/log/rs0.log child process started successfully, parent exiting # netstat -ntpl|grep :2000 tcp 0 0 0.0.0.0:30000 0.0.0.0:* LISTEN 1968/mongod
mongodb端口30001启动
# mongod -f /etc/30001.conf about to fork child process, waiting until server is ready for connections. forked process: 2033 all output going to: /opt/log/rs1.log child process started successfully, parent exiting # netstat -ntpl|grep :2000 tcp 0 0 0.0.0.0:30000 0.0.0.0:* LISTEN 1968/mongod tcp 0 0 0.0.0.0:30001 0.0.0.0:* LISTEN 2033/mongod
mongodb端口30002启动
# mongod -f /etc/30002.conf about to fork child process, waiting until server is ready for connections. forked process: 2083 all output going to: /opt/log/rs2.log child process started successfully, parent exiting # netstat -ntpl|grep :2000 tcp 0 0 0.0.0.0:30000 0.0.0.0:* LISTEN 1968/mongod tcp 0 0 0.0.0.0:30001 0.0.0.0:* LISTEN 2033/mongod tcp 0 0 0.0.0.0:30002 0.0.0.0:* LISTEN 2083/mongod
机器实际操作如下：
终端方式只是测试启动各个replica sets，此方式与上面是一样，只不过我没有使用配置文件方式启动，生产环境请使用配置文件方式启动！下面方式启动各个mongod实例是一样的！
[root@localhost opt]# mongod --replSet zxl --dbpath=/opt/rs0/ --logpath=/opt/logs/rs0.log --logappend --port 30000 --fork about to fork child process, waiting until server is ready for connections. forked process: 1671 child process started successfully, parent exiting [root@localhost opt]# mongod --replSet zxl --dbpath=/opt/rs1/ --logpath=/opt/logs/rs1.log --logappend --port 30001 --fork about to fork child process, waiting until server is ready for connections. forked process: 1717 child process started successfully, parent exiting [root@localhost opt]# mongod --replSet zxl --dbpath=/opt/rs2/ --logpath=/opt/logs/rs2.log --logappend --port 30002 --fork about to fork child process, waiting until server is ready for connections. forked process: 1764 child process started successfully, parent exiting [root@localhost opt]#
5：登录mongodb端口为30000
[root@localhost opt]# mongo --port 30000 MongoDB shell version: 2.6.11 connecting to: 127.0.0.1:30000/test > db test
注：以下是添加复制集的主机，id:zxl复制集的名称，相当于一个小组。{_id:0,host: '192.168.33.131:30000'}是添加对应的id以及主机ip和端口，默认先添加谁，谁就是主，如果设置优先级就另说了.....
> cfg={_id:'zxl',members:[
... {_id:0,host: '192.168.33.131:30000'},
... {_id:1,host: '192.168.33.131:30001'},
... {_id:2,host: '192.168.33.131:30002'}]
... }
{
"_id" : "zxl",
"members" : [
{
"_id" : 0,
"host" : "192.168.33.131:30000"
},
{
"_id" : 1,
"host" : "192.168.33.131:30001"
},
{
"_id" : 2,
"host" : "192.168.33.131:30002"
}
]
}
> rs.initiate(cfg)
{
"info" : "Config now saved locally. Should come online in about a minute.",
"ok" : 1
}
注：初始化
[22:3:2]> rs.initiate(cfg)
[22:3:2]{
[22:3:2] "info" : "Config now saved locally. Should come online in about a minute.",
[22:3:2] "ok" : 1
[22:3:2]}
注：显示状态
> rs.status()
{
"set" : "zxl",
"date" : ISODate("2015-12-13T21:48:42Z"),
"myState" : 1,
"members" : [
{
"_id" : 0,
"name" : "192.168.33.131:30000",
"health" : 1,
"state" : 1,
"stateStr" : "PRIMARY",
"uptime" : 140,
"optime" : Timestamp(1450043304, 1),
"optimeDate" : ISODate("2015-12-13T21:48:24Z"),
"electionTime" : Timestamp(1450043313, 1),
"electionDate" : ISODate("2015-12-13T21:48:33Z"),
"self" : true
},
{
"_id" : 1,
"name" : "192.168.33.131:30001",
"health" : 1,
"state" : 5,
"stateStr" : "STARTUP2",
"uptime" : 17,
"optime" : Timestamp(0, 0),
"optimeDate" : ISODate("1970-01-01T00:00:00Z"),
"lastHeartbeat" : ISODate("2015-12-13T21:48:41Z"),
"lastHeartbeatRecv" : ISODate("2015-12-13T21:48:41Z"),
"pingMs" : 0,
"lastHeartbeatMessage" : "initial sync need a member to be primary or secondary to do our initial sync"
},
{
"_id" : 2,
"name" : "192.168.33.131:30002",
"health" : 1,
"state" : 5,
"stateStr" : "STARTUP2",
"uptime" : 17,
"optime" : Timestamp(0, 0),
"optimeDate" : ISODate("1970-01-01T00:00:00Z"),
"lastHeartbeat" : ISODate("2015-12-13T21:48:41Z"),
"lastHeartbeatRecv" : ISODate("2015-12-13T21:48:42Z"),
"pingMs" : 0,
"lastHeartbeatMessage" : "initial sync need a member to be primary or secondary to do our initial sync"
}
],
"ok" : 1
}
注：以上显示各个复制集的主机信息以及是否主或者从等等信息
6：查看是否是主的master的信息如下
zxl:PRIMARY> db.isMaster()
{
"setName" : "zxl",
"setVersion" : 1,
"ismaster" : true,
"secondary" : false,
"hosts" : [
"192.168.33.131:30000",
"192.168.33.131:30002",
"192.168.33.131:30001"
],
"primary" : "192.168.33.131:30000",
"me" : "192.168.33.131:30000",
"electionId" : ObjectId("566de7b2a25a61b157882302"),
"maxBsonObjectSize" : 16777216,
"maxMessageSizeBytes" : 48000000,
"maxWriteBatchSize" : 1000,
"localTime" : ISODate("2015-12-13T21:48:58.224Z"),
"maxWireVersion" : 2,
"minWireVersion" : 0,
"ok" : 1
}
创建一个数据库ceshi，并插入数据
zxl:PRIMARY> use ceshi
switched to db ceshi
zxl:PRIMARY> db
ceshi
zxl:PRIMARY> db.a.insert({name:"xiaoer",age:33})
WriteResult({ "nInserted" : 1 })
7：mongodb端口30001登录，已经显示为从节点
[root@localhost ~]# mongo --port 30001 MongoDB shell version: 2.6.11 connecting to: 127.0.0.1:30001/test zxl:SECONDARY> db test
也可以在从节点查看是否为master命令如下：
zxl:SECONDARY> db.isMaster()
{
"setName" : "zxl",
"setVersion" : 1,
"ismaster" : false,
"secondary" : true,
"hosts" : [
"192.168.33.131:30001",
"192.168.33.131:30002",
"192.168.33.131:30000"
],
"primary" : "192.168.33.131:30000",
"me" : "192.168.33.131:30001",
"maxBsonObjectSize" : 16777216,
"maxMessageSizeBytes" : 48000000,
"maxWriteBatchSize" : 1000,
"localTime" : ISODate("2015-12-13T21:51:55.807Z"),
"maxWireVersion" : 2,
"minWireVersion" : 0,
"ok" : 1
}
此时从节点是没有查询权限，需进行rs.slaveOk()即可
zxl:SECONDARY> rs.slaveOk()
zxl:SECONDARY> show tables;
a
system.indexes
zxl:SECONDARY> db.a.find()
{ "_id" : ObjectId("566de8054436414a1c849a93"), "name" : "xiaoer", "age" : 33 }
8：把主节点端口为30000的停止，看从节点是否成为主的，操作如下
zxl:PRIMARY> use admin
switched to db admin
zxl:PRIMARY> db.shutdownServer()
2015-12-14T06:15:18.778+0800 DBClientCursor::init call() failed
server should be down...
2015-12-14T06:15:18.781+0800 trying reconnect to 127.0.0.1:30000 (127.0.0.1) failed
2015-12-14T06:15:18.782+0800 warning: Failed to connect to 127.0.0.1:30000, reason: errno:111 Connection refused
2015-12-14T06:15:18.782+0800 reconnect 127.0.0.1:30000 (127.0.0.1) failed failed couldn't connect to server 127.0.0.1:30000 (127.0.0.1), connection attempt failed
2015-12-14T06:15:18.786+0800 trying reconnect to 127.0.0.1:30000 (127.0.0.1) failed
2015-12-14T06:15:18.787+0800 warning: Failed to connect to 127.0.0.1:30000, reason: errno:111 Connection refused
2015-12-14T06:15:18.787+0800 reconnect 127.0.0.1:30000 (127.0.0.1) failed failed couldn't connect to server 127.0.0.1:30000 (127.0.0.1), connection attempt failed
> exit
bye
9：登录从节点端口30001、30002，并分别登录如下
[root@localhost ~]# mongo --port 30001
MongoDB shell version: 2.6.11
connecting to: 127.0.0.1:30001/test
zxl:SECONDARY>
zxl:PRIMARY> db.isMaster()
{
"setName" : "zxl",
"setVersion" : 1,
"ismaster" : true,
"secondary" : false,
"hosts" : [
"192.168.33.131:30001",
"192.168.33.131:30002",
"192.168.33.131:30000"
],
"primary" : "192.168.33.131:30001",
"me" : "192.168.33.131:30001",
"electionId" : ObjectId("566dedfbdc32e033bb4d0e18"),
"maxBsonObjectSize" : 16777216,
"maxMessageSizeBytes" : 48000000,
"maxWriteBatchSize" : 1000,
"localTime" : ISODate("2015-12-13T22:16:10.788Z"),
"maxWireVersion" : 2,
"minWireVersion" : 0,
"ok" : 1
}
30002登陆查看
[root@localhost ~]# mongo --port 30002
MongoDB shell version: 2.6.11
connecting to: 127.0.0.1:30002/test
zxl:SECONDARY> db.isMaster()
{
"setName" : "zxl",
"setVersion" : 1,
"ismaster" : false,
"secondary" : true,
"hosts" : [
"192.168.33.131:30002",
"192.168.33.131:30001",
"192.168.33.131:30000"
],
"primary" : "192.168.33.131:30001",
"me" : "192.168.33.131:30002",
"maxBsonObjectSize" : 16777216,
"maxMessageSizeBytes" : 48000000,
"maxWriteBatchSize" : 1000,
"localTime" : ISODate("2015-12-13T22:17:57.891Z"),
"maxWireVersion" : 2,
"minWireVersion" : 0,
"ok" : 1
}
注：此时端口30001的已经成为主节点，进行插入数据等等
zxl:PRIMARY> use ceshi
switched to db ceshi
zxl:PRIMARY> show tables;
a
system.indexes
zxl:PRIMARY> db.a.insert({a:1})
WriteResult({ "nInserted" : 1 })
zxl:PRIMARY> db.a.find()
{ "_id" : ObjectId("566de8054436414a1c849a93"), "name" : "xiaoer", "age" : 33 }
{ "_id" : ObjectId("566def04cbb79452107c217f"), "a" : 1 }
登录另一个端口30002的进行查看，操作如下：
zxl:SECONDARY> show dbs
admin (empty)
ceshi 0.078GB
local 1.078GB
test (empty)
zxl:SECONDARY> use ceshi
switched to db ceshi
zxl:SECONDARY> show tables;
2015-12-14T06:20:29.891+0800 error: { "$err" : "not master and slaveOk=false", "code" : 13435 } at src/mongo/shell/query.js:131
zxl:SECONDARY> rs.slaveOk()
zxl:SECONDARY> show tables;
a
system.indexes
zxl:SECONDARY> db.a.find()
{ "_id" : ObjectId("566de8054436414a1c849a93"), "name" : "xiaoer", "age" : 33 }
{ "_id" : ObjectId("566def04cbb79452107c217f"), "a" : 1 }
zxl:SECONDARY>
注：以上可以进行查询到端口30001的新的节点数据，但是从节点30002，查询时出现错误，需要设置为rs.slaveOk()即可，不过配置文件是可以设置的。
以上就是mongodb replSet复制集