mysql一主和双主区别 mysql一主两从优势

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云端筑梦大师 2023-10-12 14:09:51

文章标签 mysql一主和双主区别 mysql xml 读写分离 文章分类 MySQL 数据库

、MySQL主从复制

1、简介

我们为什么要用主从复制？

主从复制目的：

可以做数据库的实时备份，保证数据的完整性；

可做读写分离，主服务器只管写，从服务器只管读，这样可以提升整体性能。

2、更改配置文件

两天机器都操作，确保 server-id 要不同，通常主ID要小于从ID。一定注意。

服务器（主）:192.168.1.192

服务器（从）:192.168.1.179

# 打开log-bin,并使server-id不一样

#vim /etc/my.cnf
log-bin = mysql-bin
server-id = 1
#vim /etc/my.cnf 
log-bin = mysql-bin 
server-id = 3

#检查
1、
[root@bogon ~]# egrep "log-bin|server-id" /etc/my.cnf 
log-bin = mysql-bin
server-id = 1
[root@bogon ~]# egrep "log-bin|server-id" /etc/my.cnf  
log-bin = mysql-bin
server-id = 3
2、
[root@localhost ~]# mysql -usystem -p -S /application/mysql-5.5.33/tmp/mysql.sock -e "show variables like 'log_bin';"
Enter password: 
+-----------------------+--------+
| Variable_name | Value |
+-----------------------+--------+
| log_bin       | ON  |    # ON 为开始开启成功
+-----------------------+--------+

3、建立用于从库复制的账号qiu

通常会创建一个用于主从复制的专用账户，不要忘记授权。

# 主库授权，允许从库来连接我取日志
[root@localhost ~]# mysql -usystem -p -S  /application/mysql-5.5.33/tmp/mysql.sock

Enter password:

# 允许从库192.168.1网段连接，账号qiu，密码oldgirl。
mysql> grant replication slave on *.* to 'qiu'@'192.168.1.%' identified by 'oldgirl';

mysql> flush privileges;

/*这里特别要注意要么关闭防火墙，要么开启端口*/

4、备份主库，及恢复到从库

把主库现有数据备份下来，再恢复到从库，此时两个主机的数据一致。

如果事先有数据的话，这不不能忘。

1)    在主库上加锁，使只有只读权限。
mysql> flush table with read lock;
Query OK, 0 rows affected (0.00 sec)
#5.1、5.5锁表命令略有不同。
# 5.1锁表：flush tables with read lock;
# 5.5锁表：flush table with read lock;

2)    记住就是这个点备份的。
mysql> show master status;
+---------------------------+-------------+-------------------+--------------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+----------------------------+------------+--------------------+-------------------------+
| mysql-bin.000013  |   410 |             |               |
+----------------------------+------------+--------------------+-------------------------+
1 row in set (0.00 sec)
3)    克隆窗口，备份数据。

1: 记录为CHANGE MASTER TO 语句、语句不被注释

2: 记录为注释的CHANGE MASTER TO语
句

           --events: 备份事件调度器

grep -i "change master to" master-data.sql

vim /opt/rep.sql.gz
-- CHANGE MASTER TO MASTER_LOG_FILE='mysql-bin.000001', MASTER_LOG_POS=781215118;

4)    查看master status；数值是否正常

5)    解锁库
mysql> unlock tables;
Query OK, 0 rows affected (0.00 sec)

6)    恢复到从库
[root@bogon ~]# gunzip < /opt/qiu.sql.gz | mysql -uroot -p

5、配置从库及生效

更改从库和主库的连接参数，配置生效。检查就成功了！

1)    进入从库。
[root@bogon ~]# mysql -uroot -p
Enter password:

2)    更改从属服务器用于与主服务器进行连接和通讯的参数。
mysql> CHANGE MASTER TO
      MASTER_HOST='192.168.1.192',
      MASTER_PORT=3306,
      MASTER_USER='qiu',
      MASTER_PASSWORD='oldgirl',
      MASTER_LOG_FILE='mysql-bin.000001',
      MASTER_LOG_POS=781215118

3)    查看更改的参数。

[root@localhost data]# cat master.info 
18
mysql-bin.000013
410
192.168.200.98
REP
nick
3306
60
0

4)    生效！
mysql> start slave;

5)    检查下列参数，符合则正常！
mysql> show slave status\G
Relay_Master_Log_File: mysql-bin.000001
             Slave_IO_Running: Yes        #取logo。
            Slave_SQL_Running: Yes        #读relay-bin、logo,写数据。
Seconds_Behind_Master: 0        #落后主库的秒数。

6)    查看relay-bin.logo。

[root@localhost 3307]# cat relay-log.info 
/data/3307/relay-bin.000002
340
mysql-bin.000013
497

8)    查看master.info。
[root@localhost 3307]# cat data/master.info 
18
mysql-bin.000013
497
192.168.200.98
rep
nick
3306
60
0


0
1800.000

0

Amoeba实现读写分离

一、Amoeba 是什么

Amoeba(变形虫)项目，专注分布式数据库 proxy 开发。座落与Client、DB Server(s)之间。对客户端透明。具有负载均衡、高可用性、sql过滤、读写分离、可路由相关的query到目标数据库、可并发请求多台数据库合并结果。

主要解决：

• 降低数据切分带来的复杂多数据库结构

• 提供切分规则并降低数据切分规则给应用带来的影响

• 降低db 与客户端的连接数

• 读写分离

二、为什么要用Amoeba

目前要实现mysql的主从读写分离，主要有以下几种方案：

1、通过程序实现，网上很多现成的代码，比较复杂，如果添加从服务器要更改多台服务器的代码。

2、通过mysql-proxy来实现，由于mysql-proxy的主从读写分离是通过lua脚本来实现，目前lua的脚本的开发跟不上节奏，而写没有完美的现成的脚本，因此导致用于生产环境的话风险比较大，据网上很多人说mysql-proxy的性能不高。

3、自己开发接口实现，这种方案门槛高，开发成本高，不是一般的小公司能承担得起。

4、利用阿里巴巴的开源项目Amoeba来实现，具有负载均衡、高可用性、sql过滤、读写分离、可路由相关的query到目标数据库，并且安装配置非常简单。国产的开源软件，应该支持，目前正在使用，不发表太多结论，一切等测试完再发表结论吧，哈哈！

Amoeba框架是居于JDK1.5开发的，采用了JDK1.5的特性，所以还需要安装java环境，建议使用javaSE1.5以上的JDK版本

1、安装java环境

tar -xf jdk-8u11-linux-x64.tar.gz -C /usr/local/java

2.然后设置java环境变量

vim /etc/profile

export JAVA_HOME=/usr/local/java/
export JRE_HOME=/usr/local/java
export CLASSPATH=.:$JAVA_HOME/lib:$JRE_HOME/lib
export PATH=$JAVA_HOME/bin:$PATH

3.source /etc/profile

4.测试是否安装成功

java -version

java version "1.8.0_111"
Java(TM) SE Runtime Environment (build 1.8.0_111-b14)
Java HotSpot(TM) 64-Bit Server VM (build 25.111-b14, mixed mode)

2、安装Amoeba
Amoeba安装非常简单，直接解压即可使用，这里将Amoeba解压到/usr/local/amoeba目录下，这样就安装完成了

[root@bogon amoeba]# pwd
/usr/local/amoeba

[root@bogon amoeba]# ll
总用量 20
drwxrwxrwx. 2 root root 4096 7月 5 2013 benchmark
drwxrwxrwx. 2 root root 4096 7月 5 2013 bin
drwxrwxrwx. 2 root root 4096 7月 5 2013 conf
-rwxrwxrwx. 1 root root 728 7月 5 2013 jvm.properties
drwxrwxrwx. 2 root root 4096 7月 5 2013 lib

3、配置Amoeba

Amoeba的配置文件在本环境下位于/usr/local/amoeba/conf目录下。配置文件比较多，但是仅仅使用读写分离功能，只需配置两个文件即可，分别是dbServers.xml和amoeba.xml，如果需要配置ip访问控制，还需要修改access_list.conf文件，下面首先介绍dbServers.xml

[root@bogon amoeba]# cat conf/dbServers.xml 
<?xml version="1.0" encoding="gbk"?>

<!DOCTYPE amoeba:dbServers SYSTEM "dbserver.dtd">
<amoeba:dbServers xmlns:amoeba="http://amoeba.meidusa.com/">

        <!-- 
            Each dbServer needs to be configured into a Pool,
            If you need to configure multiple dbServer with load balancing that can be simplified by the following configuration:
             add attribute with name virtual = "true" in dbServer, but the configuration does not allow the element with name factoryConfig
             such as 'multiPool' dbServer   
        -->
        
    <dbServer name="abstractServer" abstractive="true">
        <factoryConfig class="com.meidusa.amoeba.mysql.net.MysqlServerConnectionFactory">
            <property name="connectionManager">${defaultManager}</property>
            <property name="sendBufferSize">64</property>
            <property name="receiveBufferSize">128</property>
                
            <!-- mysql port -->
            <property name="port">3306</property>　　#设置Amoeba要连接的mysql数据库的端口，默认是3306
            
            <!-- mysql schema -->
            <property name="schema">testdb</property>　　#设置缺省的数据库，当连接amoeba时，操作表必须显式的指定数据库名，即采用dbname.tablename的方式，不支持 use dbname指定缺省库，因为操作会调度到各个后端dbserver
            
            <!-- mysql user -->
            <property name="user">test1</property>　　#设置amoeba连接后端数据库服务器的账号和密码，因此需要在所有后端数据库上创建该用户，并授权amoeba服务器可连接
            
            <property name="password">111111</property>
        </factoryConfig>

        <poolConfig class="com.meidusa.toolkit.common.poolable.PoolableObjectPool">
            <property name="maxActive">500</property>　　#最大连接数，默认500
            <property name="maxIdle">500</property>　　　　#最大空闲连接数
            <property name="minIdle">1</property>　　　　#最新空闲连接数
            <property name="minEvictableIdleTimeMillis">600000</property>
            <property name="timeBetweenEvictionRunsMillis">600000</property>
            <property name="testOnBorrow">true</property>
            <property name="testOnReturn">true</property>
            <property name="testWhileIdle">true</property>
        </poolConfig>
    </dbServer>

    <dbServer name="writedb"  parent="abstractServer">　　#设置一个后端可写的dbServer，这里定义为writedb，这个名字可以任意命名，后面还会用到
        <factoryConfig>
            <!-- mysql ip -->
            <property name="ipAddress">192.168.2.204</property> #设置后端可写dbserver
        </factoryConfig>
    </dbServer>
    
    <dbServer name="slave"  parent="abstractServer">　　#设置后端可读dbserver
        <factoryConfig>
            <!-- mysql ip -->
            <property name="ipAddress">192.168.2.205</property>
        </factoryConfig>
    </dbServer>
    
    <dbServer name="myslave" virtual="true">　　#设置定义一个虚拟的dbserver，实际上相当于一个dbserver组，这里将可读的数据库ip统一放到一个组中，将这个组的名字命名为myslave
        <poolConfig class="com.meidusa.amoeba.server.MultipleServerPool">
            <!-- Load balancing strategy: 1=ROUNDROBIN , 2=WEIGHTBASED , 3=HA-->
            <property name="loadbalance">1</property>　　#选择调度算法，1表示复制均衡，2表示权重，3表示HA， 这里选择1
            
            <!-- Separated by commas,such as: server1,server2,server1 -->
            <property name="poolNames">slave</property>　　#myslave组成员
        </poolConfig>
    </dbServer>
        
</amoeba:dbServers>

4.另一个配置文件amoeba.xml

[root@bogon amoeba]# cat conf/amoeba.xml
<?xml version="1.0" encoding="gbk"?>

<!DOCTYPE amoeba:configuration SYSTEM "amoeba.dtd">
<amoeba:configuration xmlns:amoeba="http://amoeba.meidusa.com/">

<proxy>


<service name="Amoeba for Mysql" class="com.meidusa.amoeba.mysql.server.MySQLService">

<property name="port">8066</property>　　　　#设置amoeba监听的端口，默认是8066

　　　　#下面配置监听的接口，如果不设置，默认监听所以的IP


<property name="connectionFactory">
<bean class="com.meidusa.amoeba.mysql.net.MysqlClientConnectionFactory">
<property name="sendBufferSize">128</property>
<property name="receiveBufferSize">64</property>
</bean>
</property>

<property name="authenticateProvider">
<bean class="com.meidusa.amoeba.mysql.server.MysqlClientAuthenticator">

# 提供客户端连接amoeba时需要使用这里设定的账号 (这里的账号密码和amoeba连接后端数据库服务器的密码无关)

<property name="password">123456</property>

<property name="filter">
<bean class="com.meidusa.toolkit.net.authenticate.server.IPAccessController">
<property name="ipFile">${amoeba.home}/conf/access_list.conf</property>
</bean>
</property>
</bean>
</property>

</service>

<runtime class="com.meidusa.amoeba.mysql.context.MysqlRuntimeContext">


<property name="executeThreadSize">128</property>


<property name="statementCacheSize">500</property>


<property name="serverCharset">utf8</property>


<property name="queryTimeout">60</property>
</runtime>

</proxy>


<connectionManagerList>
<connectionManager name="defaultManager" class="com.meidusa.toolkit.net.MultiConnectionManagerWrapper">
<property name="subManagerClassName">com.meidusa.toolkit.net.AuthingableConnectionManager</property>
</connectionManager>
</connectionManagerList>


<dbServerLoader class="com.meidusa.amoeba.context.DBServerConfigFileLoader">
<property name="configFile">${amoeba.home}/conf/dbServers.xml</property>
</dbServerLoader>

<queryRouter class="com.meidusa.amoeba.mysql.parser.MysqlQueryRouter">
<property name="ruleLoader">
<bean class="com.meidusa.amoeba.route.TableRuleFileLoader">
<property name="ruleFile">${amoeba.home}/conf/rule.xml</property>
<property name="functionFile">${amoeba.home}/conf/ruleFunctionMap.xml</property>
</bean>
</property>
<property name="sqlFunctionFile">${amoeba.home}/conf/functionMap.xml</property>
<property name="LRUMapSize">1500</property>
<property name="defaultPool">writedb</property>　　#设置amoeba默认的池，这里设置为writedb

<property name="writePool">writedb</property>　　#这两个选项默认是注销掉的，需要取消注释，这里用来指定前面定义好的俩个读写池
<property name="readPool">myslave</property>　　 #

<property name="needParse">true</property>
</queryRouter>
</amoeba:configuration>

5.分别在masterdb和slavedb上为amoedb授权

mysql> GRANT ALL ON testdb.* TO 'test1'@'192.168.2.203' IDENTIFIED BY '111111';

flush privileges;

6.启动amoeba

[root@bogon amoeba]# /usr/local/amoeba/bin/launcher
Error: JAVA_HOME environment variable is not set.
[root@bogon amoeba]# vim /etc/profile^C
[root@bogon amoeba]# source /etc/profile
[root@bogon amoeba]# /usr/local/amoeba/bin/launcher
Java HotSpot(TM) 64-Bit Server VM warning: ignoring option PermSize=16m; support was removed in 8.0
Java HotSpot(TM) 64-Bit Server VM warning: ignoring option MaxPermSize=96m; support was removed in 8.0

The stack size specified is too small, Specify at least 228k
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.

报错:

Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.

从错误文字上看，应该是由于stack size太小，导致JVM启动失败，要如何修改呢？
其实Amoeba已经考虑到这个问题，并将JVM参数配置写在属性文件里。现在，让我们通过该属性文件修改JVM参数。
修改jvm.properties文件JVM_OPTIONS参数。

[root@bogon amoeba]# vim /usr/local/amoeba/jvm.properties 
改成：JVM_OPTIONS="-server -Xms1024m -Xmx1024m -Xss256k -XX:PermSize=16m -XX:MaxPermSize=96m"
原为：JVM_OPTIONS="-server -Xms256m -Xmx1024m -Xss196k -XX:PermSize=16m -XX:MaxPermSize=96m"

再次启动

[root@bogon ~]# /usr/local/amoeba/bin/launcher
at org.codehaus.plexus.classworlds.launcher.Launcher.launchStandard(Launcher.java:329)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:239)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:409)
at org.codehaus.classworlds.Launcher.mainWithExitCode(Launcher.java:127)
at org.codehaus.classworlds.Launcher.main(Launcher.java:110)
Caused by: com.meidusa.toolkit.common.bean.util.InitialisationException: default pool required!,defaultPool=writedb invalid
at com.meidusa.amoeba.route.AbstractQueryRouter.init(AbstractQueryRouter.java:469)
at com.meidusa.amoeba.context.ProxyRuntimeContext.initAllInitialisableBeans(ProxyRuntimeContext.java:337)
... 11 more
2016-10-24 18:46:37 [INFO] Project Name=Amoeba-MySQL, PID=1577 , System shutdown ....
Java HotSpot(TM) 64-Bit Server VM warning: ignoring option PermSize=16m; support was removed in 8.0
Java HotSpot(TM) 64-Bit Server VM warning: ignoring option MaxPermSize=96m; support was removed in 8.0
2016-10-24 18:50:19 [INFO] Project Name=Amoeba-MySQL, PID=1602 , starting...
log4j:WARN log4j config load completed from file:/usr/local/amoeba/conf/log4j.xml
2016-10-24 18:50:21,668 INFO context.MysqlRuntimeContext - Amoeba for Mysql current versoin=5.1.45-mysql-amoeba-proxy-3.0.4-BETA
log4j:WARN ip access config load completed from file:/usr/local/amoeba/conf/access_list.conf
2016-10-24 18:50:22,852 INFO net.ServerableConnectionManager - Server listening on 0.0.0.0/0.0.0.0:8066.

7.查看端口

5、测试

远程登陆mysql客户端通过指定amoeba配置文件中指定的用户名、密码、和端口以及amoeba服务器ip地址链接mysql数据库

[root@lys2 ~]# mysql -h192.168.2.203 -uroot -p -P8066
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1364055863
Server version: 5.1.45-mysql-amoeba-proxy-3.0.4-BETA Source distribution

Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql>

在testdb中创建表test并插入数据

mysql> use testdb;
Database changed
mysql> create table test_table(id int,password varchar(40) not null);
Query OK, 0 rows affected (0.19 sec)

mysql> show tables;
+------------------+
| Tables_in_testdb |
+------------------+
| test_table       |
+------------------+
1 row in set (0.02 sec)

mysql> insert into test_table(id,password) values('1','test1');
Query OK, 1 row affected (0.04 sec)

mysql> select * from test_table;
+------+----------+
| id   | password |
+------+----------+
|    1 | test1    |
+------+----------+
1 row in set (0.02 sec)

分别登陆masterdb和slavedb查看数据

masterdb：

mysql> use testdb;
Database changed
mysql> show tables;
+------------------+
| Tables_in_testdb |
+------------------+
| test_table       |
+------------------+
1 row in set (0.00 sec)

mysql> select * from test_table;
+------+----------+
| id   | password |
+------+----------+
|    1 | test1    |
+------+----------+
1 row in set (0.03 sec)

mysql一主和双主区别 mysql一主两从优势_mysql

slavedb：

mysql> use testdb;
Database changed
mysql> show tables;
+------------------+
| Tables_in_testdb |
+------------------+
| test_table       |
+------------------+
1 row in set (0.00 sec)

mysql> select * from test_table;
+------+----------+
| id   | password |
+------+----------+
|    1 | test1    |
+------+----------+
1 row in set (0.00 sec

停掉masterdb，然后在客户端分别执行插入和查询功能

masterdb：

　　[root@bogon ~]# service mysqld stop
　　Shutting down MySQL. SUCCESS!

客户端：

mysql> insert into test_table(id,password) values('2','test2');
ERROR 1044 (42000): Amoeba could not connect to MySQL server[192.168.2.204:3306],拒绝连接
mysql> select * from test_table;
+------+----------+
| id   | password |
+------+----------+
|    1 | test1    |
+------+----------+
1 row in set (0.01 sec)

mysql一主和双主区别 mysql一主两从优势_mysql

可以看到，关掉masterdb和写入报错，读正常

开启masterdb上的msyql 关闭slave上的mysql

masterdb：

[root@bogon ~]# service mysqld start
Starting MySQL.. SUCCESS!

slavedb：

[root@localhost ~]# service mysqld stop
Shutting down MySQL. SUCCESS!

客户端再次尝试

mysql> insert into test_table(id,password) values('2','test2');
Query OK, 1 row affected (0.19 sec)

mysql> select * from test_table;
ERROR 1044 (42000): poolName=myslave, no valid pools

可以看到插入成功，读取失败

开启slavedb上的mysql，查看数据是否自动同步

slavedb:

[root@localhost ~]# service mysqld start
Starting MySQL... SUCCESS!

客户端：

mysql一主和双主区别 mysql一主两从优势_mysql

mysql> select * from test_table;
+------+----------+
| id   | password |
+------+----------+
|    1 | test1    |
|    2 | test2    |
+------+----------+
2 rows in set (0.01 sec)

mysql一主和双主区别 mysql一主两从优势_mysql

接着客户端：

mysql一主和双主区别 mysql一主两从优势_mysql

mysql> insert into test_table(id,password) values('3','test3');
Query OK, 1 row affected (0.03 sec)

mysql> select * from test_table;
+------+----------+
| id   | password |
+------+----------+
|    1 | test1    |
|    2 | test2    |
|    3 | test3    |
+------+----------+
3 rows in set (0.02 sec)

mysql一主和双主区别 mysql一主两从优势_mysql

OK 一切正常，到此全部结束

实现双主模式

2、修改mysql的配置文件

首先修改DB1主机的配置文件，在/etc/my.cnf文件中的[mysqld]段添加以下内容

mysql一主和双主区别 mysql一主两从优势_mysql

[root@bogon ~]# vim /etc/my.cnf
server-id = 1　　　　#节点标示，主从节点不能相同，必须全局唯一
log-bin=mysql-bin　　#开启mysql的binlog日志功能
relay-log = mysql-relay-bin 　　#开启relay-log日志，relay-log日志记录的是从服务器I/O线程将主服务器的二进制日志读取过来记录到从服务器本地文件，然后SQL线程会读取relay-log日志的内容并应用到从服务器
replicate-wild-ignore-table=mysql.%　　#复制过滤选项
replicate-wild-ignore-table=test.%
replicate-wild-ignore-table=information_schema.%

mysql一主和双主区别 mysql一主两从优势_mysql

然后修改DB2主机的配置文件，

mysql一主和双主区别 mysql一主两从优势_mysql

[root@localhost ~]# vim /etc/my.cnf
server-id = 2
log-bin=mysql-bin
relay-log = mysql-relay-bin
replicate-wild-ignore-table=mysql.%
replicate-wild-ignore-table=test.%
replicate-wild-ignore-table=information_schema.%

mysql一主和双主区别 mysql一主两从优势_mysql

最后分别重启DB1和DB2使配置生效

3、创建复制用户并授权

注：在执行主主互备之前要保证两台server上数据一致

首先在DB1的mysql库中创建复制用户

mysql一主和双主区别 mysql一主两从优势_mysql

mysql> grant replication slave on *.* to 'repl_user'@'192.168.2.205' identified by 'repl_passwd';
Query OK, 0 rows affected (0.04 sec)

mysql> show master status;
+------------------+----------+--------------+------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000004 |      271 |              |                  |
+------------------+----------+--------------+------------------+
1 row in set (0.00 sec)

mysql一主和双主区别 mysql一主两从优势_mysql

然后在DB2的mysql库中将DB1设为自己的主服务器

mysql一主和双主区别 mysql一主两从优势_mysql

mysql> change master to \
    -> master_host='192.168.2.204',  
    -> master_user='repl_user',
    -> master_password='repl_passwd',
    -> master_log_file='mysql-bin.000004',  
    -> master_log_pos=271;
Query OK, 0 rows affected (0.07 sec)

mysql一主和双主区别 mysql一主两从优势_mysql

这里需要注意master_log_file和master_log_pos两个选项，这两个选项的值是在DB1上通过“show master status” 查询到的结果

接着在DB2上启动slave服务

mysql> start slave;
Query OK, 0 rows affected (0.01 sec)

下面查看DB2上slave的运行状态，

mysql一主和双主区别 mysql一主两从优势_mysql

mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.2.204
                  Master_User: repl_user
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000005
          Read_Master_Log_Pos: 271
               Relay_Log_File: mysql-relay-bin.000002
                Relay_Log_Pos: 253
        Relay_Master_Log_File: mysql-bin.000005
             Slave_IO_Running: Yes　　　　#重点
            Slave_SQL_Running: Yes　　　　#重点
              Replicate_Do_DB: 
          Replicate_Ignore_DB: 
           Replicate_Do_Table: 
       Replicate_Ignore_Table: 
      Replicate_Wild_Do_Table: 
  Replicate_Wild_Ignore_Table: mysql.%,test.%,information_schema.%　　#跳过的表
                   Last_Errno: 0
                   Last_Error: 
                 Skip_Counter: 0
          Exec_Master_Log_Pos: 271
              Relay_Log_Space: 409
              Until_Condition: None
               Until_Log_File: 
                Until_Log_Pos: 0
           Master_SSL_Allowed: No
           Master_SSL_CA_File: 
           Master_SSL_CA_Path: 
              Master_SSL_Cert: 
            Master_SSL_Cipher: 
               Master_SSL_Key: 
        Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
                Last_IO_Errno: 0
                Last_IO_Error: 
               Last_SQL_Errno: 0
               Last_SQL_Error: 
  Replicate_Ignore_Server_Ids: 
             Master_Server_Id: 1
1 row in set (0.00 sec)

mysql一主和双主区别 mysql一主两从优势_mysql

到这里，从DB1到DB2的mysql主从复制已经完成。接下来开始配置从DB2到DB1的mysql主从复制

在DB2的mysql库中创建复制用户

mysql一主和双主区别 mysql一主两从优势_mysql

mysql> grant replication slave on *.* to 'repl_user'@'192.168.2.204' identified by 'repl_passwd';
Query OK, 0 rows affected (0.00 sec)

mysql> show master status;
+------------------+----------+--------------+------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000005 |      271 |              |                  |
+------------------+----------+--------------+------------------+
1 row in set (0.00 sec)

mysql一主和双主区别 mysql一主两从优势_mysql

然后在DB1的mysql库中将DB2设为自己的主服务器

mysql一主和双主区别 mysql一主两从优势_mysql

mysql> change master to \
    -> master_host='192.168.2.205',
    -> master_user='repl_user',
    -> master_password='repl_passwd',
    -> master_log_file='mysql-bin.000005',
    -> master_log_pos=271;
Query OK, 0 rows affected (0.07 sec)

mysql一主和双主区别 mysql一主两从优势_mysql

最后，在DB1上启动slave服务

mysql> start slave;
Query OK, 0 rows affected (0.01 sec)

查看DB1上slave的运行状态

mysql一主和双主区别 mysql一主两从优势_mysql

mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.2.205
                  Master_User: repl_user
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000005
          Read_Master_Log_Pos: 271
               Relay_Log_File: mysql-relay-bin.000002
                Relay_Log_Pos: 253
        Relay_Master_Log_File: mysql-bin.000005
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
              Replicate_Do_DB: 
          Replicate_Ignore_DB: 
           Replicate_Do_Table: 
       Replicate_Ignore_Table: 
      Replicate_Wild_Do_Table: 
  Replicate_Wild_Ignore_Table: mysql.%,test.%,information_schema.%
                   Last_Errno: 0
                   Last_Error: 
                 Skip_Counter: 0
          Exec_Master_Log_Pos: 271
              Relay_Log_Space: 409
              Until_Condition: None
               Until_Log_File: 
                Until_Log_Pos: 0
           Master_SSL_Allowed: No
           Master_SSL_CA_File: 
           Master_SSL_CA_Path: 
              Master_SSL_Cert: 
            Master_SSL_Cipher: 
               Master_SSL_Key: 
        Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
                Last_IO_Errno: 0
                Last_IO_Error: 
               Last_SQL_Errno: 0
               Last_SQL_Error: 
  Replicate_Ignore_Server_Ids: 
             Master_Server_Id: 2
1 row in set (0.00 sec)

mysql一主和双主区别 mysql一主两从优势_mysql

二、配置keepalived实现mysql双主高可用

1、安装keepalived

mysql一主和双主区别 mysql一主两从优势_mysql

[root@bogon src]# tar zxf keepalived-1.2.24.tar.gz 
[root@bogon src]# cd keepalived-1.2.24
[root@bogon keepalived-1.2.24]# ./configure --sysconf=/etc --with-kernel-dir=/lib/modules/2.6.32-642.3.1.el6.x86_64/
[root@bogon keepalived-1.2.24]# make && make install
[root@bogon keepalived-1.2.24]# ln -s /usr/local/sbin/keepalived /sbin/
[root@bogon keepalived-1.2.24]# chkconfig --add keepalived
[root@bogon keepalived-1.2.24]# chkconfig --level 35 keepalived on
[root@bogon keepalived-1.2.24]# yum  -y install ipvsadm  ####之前没安装ipvsadm，导致 keepalived配置中lvs配置部分不生效，其中定义的notify_down 字段死活不生效，查了好久在发现是没安装ipvsadm导致的，泪奔！！！
[root@bogon keepalived-1.2.24]# ipvsadm

mysql一主和双主区别 mysql一主两从优势_mysql

2、配置keepalived

DB1上keepalived.conf配置为

mysql一主和双主区别 mysql一主两从优势_mysql

[root@bogon keepalived-1.2.24]# cat /etc/keepalived/keepalived.conf 
! Configuration File for keepalived

global_defs {
   notification_email {
     acassen@firewall.loc
     failover@firewall.loc
     sysadmin@firewall.loc
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   smtp_server 192.168.200.1
   smtp_connect_timeout 30
   router_id LVS_DEVEL
   vrrp_skip_check_adv_addr
   vrrp_strict
   vrrp_garp_interval 0
   vrrp_gna_interval 0
}




vrrp_instance HA_1 {
    state BACKUP　　　　#在DB1和DB2上均配置为BACKUP
    interface eth1
    virtual_router_id 90 
    priority 100
    advert_int 1
    nopreempt　　　　#不抢占模式，只有优先级高的机器上设置即可，优先级低的机器可不设置
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
    192.168.2.33
    }
}

virtual_server 192.168.2.33 3306 {
     delay_loop 2
     lb_algo wrr
     lb_kind DR
     persistence_timeout 60　　#会话保持时间 
     protocol TCP
     real_server 192.168.2.204 3306 {
         weight 3
         notify_down /root/shutdown.sh　　#检测到服务down后执行的脚本 
         TCP_CHECK {
             connect_timeout 10　　#连接超时时间
             nb_get_retry 3　　　　#重连次数
             delay_before_retry 3　　 #重连间隔时间  
             connect_port 3306　　　　 #健康检查端口
         } 
     }
}

mysql一主和双主区别 mysql一主两从优势_mysql

DB2上keepalived.conf配置为

mysql一主和双主区别 mysql一主两从优势_mysql

[root@localhost keepalived-1.2.24]# cat /etc/keepalived/keepalived.conf 
! Configuration File for keepalived

global_defs {
   notification_email {
     acassen@firewall.loc
     failover@firewall.loc
     sysadmin@firewall.loc
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   smtp_server 192.168.200.1
   smtp_connect_timeout 30
   router_id LVS_DEVEL
   vrrp_skip_check_adv_addr
   vrrp_strict
   vrrp_garp_interval 0
   vrrp_gna_interval 0
}




vrrp_instance HA_1 {
    state BACKUP
    interface eth1
    virtual_router_id 90 
    priority 90
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
    192.168.2.33
    }
}

virtual_server 192.168.2.33 3306 {
     delay_loop 2
     lb_algo wrr
     lb_kind DR
     persistence_timeout 60
     protocol TCP
     real_server 192.168.2.205 3306 {
         weight 3
         notify_down /root/shutdown.sh
         TCP_CHECK {
             connect_timeout 10
             nb_get_retry 3
             delay_before_retry 3
             connect_port 3306
         } 
     }
}

mysql一主和双主区别 mysql一主两从优势_mysql

编写检测服务down后所要执行的脚本shutdown.sh

[root@bogon ~]# cat /root/shtdown.sh 
#!/bin/bash
killall keepalived

注：此脚本是上面配置文件notify_down选项所用到的，keepalived使用notify_down选项来检查real_server的服务状态，当发现real_server服务故障时，便触发此脚本；我们可以看到，脚本就一个命令，通过killall keepalived强制杀死keepalived进程，从而实现了MySQL故障自动转移。另外，我们不用担心两个MySQL会同时提供数据更新操作，因为每台MySQL上的keepalived的配置里面只有本机MySQL的IP+VIP，而不是两台MySQL的IP+VIP

启动keepalived并查看日志

mysql一主和双主区别 mysql一主两从优势_mysql

[root@bogon keepalived-1.2.24]# chmod 755 /etc/init.d/keepalived 
[root@bogon keepalived-1.2.24]# service keepalived start
正在启动 keepalived：                                      [确定]
[root@bogon keepalived-1.2.24]# tail -f /var/log/messages
Oct 24 22:37:35 bogon Keepalived_vrrp[20835]: Sending gratuitous ARP on eth1 for 192.168.2.33
Oct 24 22:37:35 bogon Keepalived_vrrp[20835]: Sending gratuitous ARP on eth1 for 192.168.2.33
Oct 24 22:37:35 bogon Keepalived_vrrp[20835]: Sending gratuitous ARP on eth1 for 192.168.2.33
Oct 24 22:37:35 bogon Keepalived_vrrp[20835]: Sending gratuitous ARP on eth1 for 192.168.2.33
Oct 24 22:37:40 bogon Keepalived_vrrp[20835]: Sending gratuitous ARP on eth1 for 192.168.2.33
Oct 24 22:37:40 bogon Keepalived_vrrp[20835]: VRRP_Instance(HA_1) Sending/queueing gratuitous ARPs on eth1 for 192.168.2.33
Oct 24 22:37:40 bogon Keepalived_vrrp[20835]: Sending gratuitous ARP on eth1 for 192.168.2.33
Oct 24 22:37:40 bogon Keepalived_vrrp[20835]: Sending gratuitous ARP on eth1 for 192.168.2.33
Oct 24 22:37:40 bogon Keepalived_vrrp[20835]: Sending gratuitous ARP on eth1 for 192.168.2.33
Oct 24 22:37:40 bogon Keepalived_vrrp[20835]: Sending gratuitous ARP on eth1 for 192.168.2.33

mysql一主和双主区别 mysql一主两从优势_mysql

三、测试功能

1、在远程客户端通过vip登陆测试

mysql一主和双主区别 mysql一主两从优势_mysql

[root@www ansible]# mysql -h 192.168.2.33 -uroot -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2372
Server version: 5.5.37-log Source distribution

Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql>

mysql一主和双主区别 mysql一主两从优势_mysql

从sql输出结果看，可以通过vip登陆，并且登陆了DB1服务器

2、创建一个数据库，然后在这个库重创建一个表，并插入数据

mysql一主和双主区别 mysql一主两从优势_mysql

mysql> create database repldb;
Query OK, 1 row affected (0.02 sec)

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| repldb             |
| test               |
+--------------------+
5 rows in set (0.06 sec)

mysql> use repldb;
Database changed
mysql> create table repl_table(id int,email varchar(80),password varchar(40) not null);
Query OK, 0 rows affected (0.03 sec)

mysql> show tables;
+------------------+
| Tables_in_repldb |
+------------------+
| repl_table       |
+------------------+
1 row in set (0.01 sec)

mysql> insert into repl_table(id,email,password) values(1,"master@163.com","qweasd");
Query OK, 1 row affected (0.00 sec)

mysql一主和双主区别 mysql一主两从优势_mysql

登陆DB2主机的mysql，可数据是否复制成功

mysql一主和双主区别 mysql一主两从优势_mysql

mysql> show variables like "%hostname%";
+---------------+-----------------------+
| Variable_name | Value                 |
+---------------+-----------------------+
| hostname      | localhost.localdomain |
+---------------+-----------------------+
1 row in set (0.01 sec)

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| repldb             |
| test               |
+--------------------+
5 rows in set (0.05 sec)

mysql> use repldb;
Database changed
mysql> show tables;
+------------------+
| Tables_in_repldb |
+------------------+
| repl_table       |
+------------------+
1 row in set (0.00 sec)


mysql> select * from repl_table;
+------+----------------+----------+
| id   | email          | password |
+------+----------------+----------+
|    1 | master@163.com | qweasd   |
+------+----------------+----------+
1 row in set (0.08 sec)

mysql一主和双主区别 mysql一主两从优势_mysql

3、停止DB1主机上的mysql，查看故障是否自动转移

[root@bogon ~]# service mysqld stop
Shutting down MySQL.. SUCCESS!

登陆192.168.2.33查看：

mysql一主和双主区别 mysql一主两从优势_mysql

mysql> show variables like "%hostname%";
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id:    610
Current database: repldb

+---------------+-----------------------+
| Variable_name | Value                 |
+---------------+-----------------------+
| hostname      | localhost.localdomain |
+---------------+-----------------------+
1 row in set (0.01 sec)

mysql一主和双主区别 mysql一主两从优势_mysql

可以看到现在登陆的是DB2 故障自动切换成功

接着，插入数据看DB1是否能复制

mysql一主和双主区别 mysql一主两从优势_mysql

mysql> insert into repl_table(id,email,password) values(2,"slave@163.com","qweasd");
Query OK, 1 row affected (0.06 sec)

mysql> use repldb;
Database changed
mysql> select * from repl_table;
+------+----------------+----------+
| id   | email          | password |
+------+----------------+----------+
|    1 | master@163.com | qweasd   |
|    2 | slave@163.com  | qweasd   |
+------+----------------+----------+
2 rows in set (0.00 sec)

mysql一主和双主区别 mysql一主两从优势_mysql

登陆DB1查看表数据

mysql一主和双主区别 mysql一主两从优势_mysql

[root@bogon ~]# service mysqld start
Starting MySQL. SUCCESS! 
[root@bogon ~]# mysql -uroot -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.5.37-log Source distribution

Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> use repldb;
Database changed
mysql> select * from repl_table;
+------+----------------+----------+
| id   | email          | password |
+------+----------------+----------+
|    1 | master@163.com | qweasd   |
|    2 | slave@163.com  | qweasd   |
+------+----------------+----------+
2 rows in set (0.02 sec)

mysql一主和双主区别 mysql一主两从优势_mysql

复制成功！

到此全部完成！！！

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