MongoDB主从复制
在生产环境中单台数据库已不能满足业务需求,数据库主从复制在架构中使用很常见,用于备份、高可用、读写分离来提高数据处理性能和冗余,常用架构模式是一主一从、一主多从、双主。但MongoDB中还不能做到双向同步,因此无法实现双主。那我们这次架构采用的是一主一从,在生产环境中主主要承担写操作,从承担读操作。
环境说明:
OS:CentOS6.5_x64
主(Master):192.168.0.201
从(Slave):192.168.0.202
主从数据库目录都在 /usr/local/mongodb/data
日志目录 /usr/local/mongodb/logs
1、主mongodb配置
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[[email protected] ~] # mkdir /usr/local/mongodb/data
[[email protected] ~] # mkdir /usr/local/mongodb/logs
[[email protected] ~] # mkdir /usr/local/mongodb/conf
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[[email protected] ~] # vi /usr/local/mongodb/conf/mongod.conf
port=27017 #端口号
fork= true #以守护进程方式运行
logpath= /usr/local/mongodb/logs/mongodb .log #日志文件
logappend= true #日志输出方式
dbpath= /usr/local/mongodb/data #数据库位置
maxConns=1024 #数据库最大连接数
master= true #主模式
oplogSize=2048 #日志滚动,单位M
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2、从Mongodb配置
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[[email protected] ~] # mkdir /usr/local/mongodb/data
[[email protected] ~] # mkdir /usr/local/mongodb/logs
[[email protected] ~] # mkdir /usr/local/mongodb/conf
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[[email protected] ~] # vi /usr/local/mongodb/conf/mongod.conf
port=27017 fork= true
logpath= /usr/local/mongodb/logs/mongodb .log
logappend= true
dbpath= /usr/local/mongodb/data
maxConns=1024 slave= true #从模式
source =192.168.0.201:27017 #指定主Mongodb
autoresync= true #自动同步
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3、添加环境变量并启动Mongodb
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[[email protected] ~] # echo "PATH=$PATH:/usr/local/mongodb/bin" >> /etc/profile
[[email protected] ~] # source /etc/profile
[[email protected] ~] # mongod -f /usr/local/mongodb/conf/mongod.conf #启动
[[email protected] ~] # netstat -tupln | grep mongod
tcp 0 0 0.0.0.0:28017 0.0.0.0:* LISTEN 1923 /mongod tcp 0 0 0.0.0.0:27017 0.0.0.0:* LISTEN 1923 /mongod
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#主上日志信息看出主数据库允许让192.168.0.202从数据库45458端口连接
#从上日志信息看出开始同步192.168.0.201主数据库
4、测试Mongodb主从复制
#创建一个数据库test,集合名也是test,插入一个字段AGE:18。然后再从数据库showdbs;查看已经同步过去。语法与Mysql有很大区别。
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[[email protected] ~] # mongo
MongoDB shell version:2.4.9-rc0 > use test
> db. test .save({AGE:18})
> db. test . find ()
{ "_id" :ObjectId( "52addd66124c02eb8b2d1a5a" ), "AGE" : 18 }
> show dbs local 2.0771484375GB
test 0.203125GB
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主日志
从日志
创建数据库后,由上主从日志看出,主允许从连接,从同步主数据(applied 1 operations)。主数据库操作记录为OpLog日志,说明主从数据库原理是定期从主服务器中获取oplog记录,然后在本机上执行。
5、查看主从复制状态
#查看主
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[[email protected] ~] # mongo
MongoDB shell version:2.4.9-rc0 connecting to: test
>db.printReplicationInfo() configured oplog size: 2048MB log length start to end:1494secs (0.42hrs) oplog first event time : Sun Dec 15 2013 10:55:37 GMT-0500 (EST)
oplog last event time : Sun Dec 15 2013 11:20:31 GMT-0500 (EST)
now: Sun Dec 15 2013 11:20:33GMT-0500 (EST) > |
#查看从
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[[email protected] ~] # mongo
MongoDB shell version: 2.4.9-rc0 connecting to: test
>db.printReplicationInfo() this is a slave, printingslave replication info. source : 192.168.0.201:27017
syncedTo: Sun Dec 15 2013 11:18:31GMT-0500 (EST)
= 21 secs ago (0.01hrs)
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#关闭Mongodb数据库
[[email protected] ~]# mongod -f/usr/local/mongodb/conf/mongod.conf --shutdown
#写一个简单的SysV管理脚本
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[[email protected] ~] # vim /etc/init.d/mongod
#!/bin/bash #chkconfig: 35 80 20 #description: Mongodb service control script PROG= "/usr/local/mongodb/bin/mongod"
CONF= "/usr/local/mongodb/conf/mongod.conf"
case $1 in
start)
$PROG -f $CONF &> /dev/null
echo "Starting mongodb: [ OK ]"
;;
stop)
$PROG -f $CONF -- shutdown &> /dev/null
echo "Shutting down mongodb: [ OK ]"
;;
restart)
$0 stop
$0 start
;;
*)
echo "Usage: $0 {start|stop|restart}"
esac |
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[[email protected] ~] # chmod +x /etc/init.d/mongod
[[email protected] ~] # chkconfig --add mongod
[[email protected] ~] # chkconfig mongod on
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Mongdb主从复制就完事了,比Myslq简单吧,比较灵活。