目标：配置一个keepalived双机热备架构，并配置主从复制
规划：
master1 zlm177 192.168.17.177
master2 zlm188 192.168.17.188
vip 192.168.17.166
环境： Red Hat Enterprise Linux 6.4
Percona Server 5.6.15
keepalived-1.2.13.tar
cp keepalived-1.2.13.tar /usr/local/src
cd /usr/local/src
tar zxvf keepalived-1.2.13.tar -C /opt/
cd /opt/keepalived-1.2.13
./configure --prefix=/usr/local/keepalived
make;makeinstall 或 make && makeinstall
注意，在编译过程中会提示缺少gcc和openssl包，用yum install装一下就能够了
RHEL6.4也能够配置CentOS的yum，详细方法这里就不讲了
yum install gcc
yum install openssl openssl-devel
还会提示xxx依赖包也须要安装，一并装上，用yum的优点就是安装方便。让系统自己主动推断须要哪些包，自己主动下载并安装。完毕编译以后，软件安装就结束了
/usr/local/keepalived/etc/keepalived/keepalived.conf
在主端打开该配置文件。把原有内容清空。再加入下面内容：
! Configuration File for keepalived
global_defs { --全局配置
notification_email {
aaron8219@xxx.xxx --接收通知的邮箱
}
router_id aaron8219 --能够用字母。也能够使数字。能够一致。也能够不一致，仅仅是一个标识
}
vrrp_instance my_177 {
state BACKUP --BACKUP从端模式
interface eth0
virtual_router_id 88 --默觉得51。取值范围在1~255的整数，主从两端必须一致。才表示是同一个组
priority 90
advert_int 1 --检查间隔，默认1s
nopreempt --设置非抢占模式,
authentication {
auth_type PASS
auth_pass 1234
}
virtual_ipaddress { --指定vip,
192.168.17.166
}
}
##关于vip的说明：vip随着state的变化而添加删除，当state为master的时候就加入。当state为backup的时候删除。主要是由优先级来决定的，和state设置的值没有多大关系(state同样的情况下)，至于vip究竟在主端还是从端，还和nopreempt有关，这里vip能够设置多个IP地址
##关于nopreempt的说明：仅仅能设置在state为backup的节点上。且这个节点的优先级必须比另外的高
virtual_server 192.168.17.166 3306 { --虚拟服务器ip和port
delay_loop 2
lb_algo wrr --带有权重的轮询
lb_kind DR
persistence_timeout 60
protocol TCP
real_server 192.168.17.177 3306 { --真实服务器ip和port
weight 3 --权重为3
notify_down /opt/mysql/mysql.sh --指定自杀脚本的路径
TCP_CHECK {
connect_timeout 10
nb_get_retry 3
delay_before_retry 3
connect_port 3306
}
}
}
从端的配置文件大同小异，仅仅要把IP和实例名改成自己的就能够了，而且设置从端的priority为90，而主端为100
有一点要注意的是，主从两端的state，都配置成了backup，由于使用了nopreempt，即非抢占模式
举个样例，当主端先启动mysql实例和keepalived后，假设此时从端也启动了mysql实例和keepalived。那么vip不会跳到从端上去。即使它的优先级为100。要大于主端的90
而假设不设置nopreempt。那么这个时候。又分2种情况：
1.state同样，即都是master或都是backup
优先级高的，会占有vip。和角色无关
2.state不同。即master->backup或backup->master
优先级高的。会占有vip，和角色无关
前提不同。结果都是一样的，即优先级是主导，谁的优先级高。vip就漂到谁那里
创建一个自杀脚本来推断mysql进程是否启动
touch /opt/mysql/mysql.sh
加入下面内容：
#!/bin.sh
pkill keepalived --表示kill掉keepalived进程
-f 指定keepalived的參数文件
-D 表示在操作系统日志里显示具体记录
推断keepalived进程是否正常启动，仅仅要查看/var/log/messages里的日志就能够了
tail -30f /var/log/message
注意。假设没有启动mysql而先启动了keepalived。那么之前notify_down參数中指定的脚本就会被运行，表示没有找到mysql进程，把keeplied自己的进程给kill掉。
Jul 25 02:51:22 zlm188 Keepalived[3440]: Starting Keepalived v1.2.13 (07/22,2014)
Jul 25 02:51:22 zlm188 Keepalived[3441]: Starting Healthcheck child process, pid=3442
Jul 25 02:51:22 zlm188 Keepalived[3441]: Starting VRRP child process, pid=3443
Jul 25 02:51:22 zlm188 Keepalived_vrrp[3443]: Netlink reflector reports IP 192.168.17.188 added
Jul 25 02:51:22 zlm188 Keepalived_healthcheckers[3442]: Netlink reflector reports IP 192.168.17.188 added
Jul 25 02:51:22 zlm188 Keepalived_healthcheckers[3442]: Netlink reflector reports IP fe80::a00:27ff:fe71:6b7b added
Jul 25 02:51:22 zlm188 Keepalived_healthcheckers[3442]: Registering Kernel netlink reflector
Jul 25 02:51:22 zlm188 Keepalived_vrrp[3443]: Netlink reflector reports IP fe80::a00:27ff:fe71:6b7b added
Jul 25 02:51:22 zlm188 Keepalived_healthcheckers[3442]: Registering Kernel netlink command channel
Jul 25 02:51:22 zlm188 Keepalived_vrrp[3443]: Registering Kernel netlink reflector
Jul 25 02:51:22 zlm188 Keepalived_vrrp[3443]: Registering Kernel netlink command channel
Jul 25 02:51:22 zlm188 Keepalived_vrrp[3443]: Registering gratuitous ARP shared channel
Jul 25 02:51:22 zlm188 Keepalived_vrrp[3443]: Opening file '/usr/local/keepalived/etc/keepalived/keepalived.conf'.
Jul 25 02:51:22 zlm188 Keepalived_healthcheckers[3442]: Opening file '/usr/local/keepalived/etc/keepalived/keepalived.conf'.
Jul 25 02:51:22 zlm188 Keepalived_healthcheckers[3442]: Configuration is using : 11566 Bytes
Jul 25 02:51:22 zlm188 Keepalived_vrrp[3443]: Configuration is using : 62964 Bytes
Jul 25 02:51:22 zlm188 Keepalived_vrrp[3443]: Using LinkWatch kernel netlink reflector...
Jul 25 02:51:22 zlm188 Keepalived_vrrp[3443]: VRRP_Instance(my_178) Entering BACKUP STATE
Jul 25 02:51:22 zlm188 Keepalived_vrrp[3443]: VRRP sockpool: [ifindex(2), proto(112), unicast(0), fd(10,11)]
Jul 25 02:51:22 zlm188 Keepalived_healthcheckers[3442]: Using LinkWatch kernel netlink reflector...
Jul 25 02:51:22 zlm188 Keepalived_healthcheckers[3442]: Activating healthchecker for service [192.168.17.188]:3306
Jul 25 02:51:25 zlm188 Keepalived_healthcheckers[3442]: TCP connection to [192.168.17.188]:3306 failed !!!
Jul 25 02:51:25 zlm188 Keepalived_healthcheckers[3442]: Removing service [192.168.17.188]:3306 from VS [192.168.17.166]:3306
Jul 25 02:51:25 zlm188 Keepalived_healthcheckers[3442]: Executing [/opt/mysql/mysql.sh] for service [192.168.17.188]:3306 in VS [192.168.17.166]:3306
Jul 25 02:51:25 zlm188 Keepalived_healthcheckers[3442]: Lost quorum 1-0=1 > 0 for VS [192.168.17.166]:3306
Jul 25 02:51:25 zlm188 Keepalived[3441]: Stopping Keepalived v1.2.13 (07/22,2014)
在从端启动keepalived，跟踪日志文件能够发现，跑了一遍以后自己主动stopping了。这也说明。之前的配置是ok的了，否则就要检查一下。哪里配置有误，尤其要注意virtual_route_id必须保持一致，而route_id则不强行要求一致。实例名也不要反复
1.检验vip的情况
#ip address show或ip a show
2.用vip登录mysql数据库(前提是已开启了mysqld和keepalived进程)
#mysql -h192.168.17.166 -uaaron8219 -pzlm
3.关闭某一端网卡后，測试vip的去向。以及能否通过vip正常登陆
#ifdown eth0
#ip a show
#mysql -h192.168.17.166 -uaaron8219 -pzlm
4.重新启动某一端(主机模拟主机故障)，測试vip的去向，以及能否通过vip正常登陆
#init 6
#ip a show
#mysql -h192.168.17.166 -uaaron8219 -pzlm
5.直接kill掉keepalived进程。測试vip的去向，以及能否通过vip正常登陆
#pkill keepalived
#ip a show
#mysql -h192.168.17.166 -uaaron8219 -pzlm
1.两端配置同步所需參数
确保server-id与slave不一致，通常server-id的格式能够设置成ip末尾2-3位+port号
比方我的环境master的ip是192.168.17.177，port是3306
那么server-id能够设置成1773306，对应地。slave就设置成1883306
下面參数都是在/etc/my.cnf文件里配置
server-id=1773306
log-bin=percona-bin --启用binlog
set-variable=binlog-ignore-db=mysql --不记录数据库mysql的更新日志，避免了Master上的权限设置等被同步到Slave上
2.两端加入复制用户
mysql> grant repliecation slave on *.* to 'rep'@'192.168.17.%' identified by 'rep';
假设想要在Slave上有权限运行 "LOAD TABLE FROM MASTER" 或 "LOAD DATA FROM MASTER" 语句的话，必须授予全局的 FILE 和 Select 权限：
mysql> GRANT FILE,Select,REPLICATION SLAVE ON *.* TO 'rep'@'%' IDENTIFIED BY 'rep';
3.设置同步
假设是新库，两边直接重置master的binlog
mysql> reset master;
②mysql> mysqldump -uroot -p --all-databases -l -F >full_db.sql
scp full_db.sql root@192.168.17.188:/data/mysql/percona_3306/data
或
②cd /data/mysql/percona_3306
tar zcvf data.tar.gz ./data
scp data.tar.gz root@192.168.17.188
③mysql> unlock tables;
从库导入主库的数据库
mysql> mysql -uroot -p </data/mysql/percona_3306/data/full_db.sql
或
mysql> source /data/mysql/percona_3306/data/full_db.sql
)
4.主库查询日志状态
mysql> show master statusG
5.从库依据主库的binlog位置和position来运行同步
6.启动slave
mysql> start slave;
启动后报错
Slave I/O: Fatal error: The slave I/O thread stops because master and slave have equal MySQL server UUIDs; these UUIDs must be different for replication to work. Error_code: 1593
由于从库是直接通过虚拟机拷贝镜像的方式创建的。所以UUID反复了，UUID是存放在
/data/mysql/percona_3306/data/auto.cnf文件里的
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.17.177
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: percona-bin.000011
Read_Master_Log_Pos: 540
Relay_Log_File: node78-relay-bin.000018
Relay_Log_Pos: 285
Relay_Master_Log_File: percona-bin.000011
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:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 540
Relay_Log_Space: 459
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: 773306
Master_UUID: 917ecbfc-10dc-11e4-b624-080027267b03
Master_Info_File: /data/mysql/percona_3306/data/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Slave has read all relay log; waiting for the slave I/O thread to update it
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set:
Auto_Position: 0
7.測试
主库測试数据库zlm的tb_zlm表中运行插入一行数据：
(testing)root@localhost [(none)]> select * from zlm.tb_zlm;
+------+-----------+
| id | name |
+------+-----------+
| 1 | aaron8219 |
| 2 | zlm |
| 3 | abc |
+------+-----------+
3 rows in set (0.00 sec)
(testing)root@localhost [(none)]> insert into zlm.tb_zlm values(4,'def');
Query OK, 1 row affected (0.03 sec)
从库查询zlm.tb_zlm表：
(testing)root@localhost [(none)]> select * from zlm.tb_zlm;
+------+-----------+
| id | name |
+------+-----------+
| 1 | aaron8219 |
| 2 | zlm |
| 3 | abc |
| 4 | def |
+------+-----------+
4 rows in set (0.00 sec)
从库上也进行相同的配置，就可以完毕互为主从，仅仅要从对应的master的binlog的pos位置開始change maseter就能够了
结论：仅仅要配置的VRRP组里面有一台机器开启了mysqld和keepalived进程，不论什么通过vip实现的数据库连接訪问，都是正常的。这样不管是哪个节点down掉了，都不会影响mysql数据库的可用性，是一个最简单的mysql高可用架构。自此，通过keepalived来实现互为主从的双机热备架构就完毕了，假设再复杂一点。安装lvpsadm来实现虚拟server的配置，那么就是一个经典的keepalived+lvs架构
规划：
master1 zlm177 192.168.17.177
master2 zlm188 192.168.17.188
vip 192.168.17.166
环境： Red Hat Enterprise Linux 6.4
Percona Server 5.6.15
一、软件安装
keepalived-1.2.13.tar
cp keepalived-1.2.13.tar /usr/local/src
cd /usr/local/src
tar zxvf keepalived-1.2.13.tar -C /opt/
cd /opt/keepalived-1.2.13
./configure --prefix=/usr/local/keepalived
make;makeinstall 或 make && makeinstall
注意，在编译过程中会提示缺少gcc和openssl包，用yum install装一下就能够了
RHEL6.4也能够配置CentOS的yum，详细方法这里就不讲了
yum install gcc
yum install openssl openssl-devel
还会提示xxx依赖包也须要安装，一并装上，用yum的优点就是安装方便。让系统自己主动推断须要哪些包，自己主动下载并安装。完毕编译以后，软件安装就结束了
二、配置软件參数（VRRP）
/usr/local/keepalived/etc/keepalived/keepalived.conf
在主端打开该配置文件。把原有内容清空。再加入下面内容：
! Configuration File for keepalived
global_defs { --全局配置
notification_email {
aaron8219@xxx.xxx --接收通知的邮箱
}
router_id aaron8219 --能够用字母。也能够使数字。能够一致。也能够不一致，仅仅是一个标识
}
vrrp_instance my_177 {
state BACKUP --BACKUP从端模式
interface eth0
virtual_router_id 88 --默觉得51。取值范围在1~255的整数，主从两端必须一致。才表示是同一个组
priority 90
advert_int 1 --检查间隔，默认1s
nopreempt --设置非抢占模式,
authentication {
auth_type PASS
auth_pass 1234
}
virtual_ipaddress { --指定vip,
192.168.17.166
}
}
##关于vip的说明：vip随着state的变化而添加删除，当state为master的时候就加入。当state为backup的时候删除。主要是由优先级来决定的，和state设置的值没有多大关系(state同样的情况下)，至于vip究竟在主端还是从端，还和nopreempt有关，这里vip能够设置多个IP地址
##关于nopreempt的说明：仅仅能设置在state为backup的节点上。且这个节点的优先级必须比另外的高
virtual_server 192.168.17.166 3306 { --虚拟服务器ip和port
delay_loop 2
lb_algo wrr --带有权重的轮询
lb_kind DR
persistence_timeout 60
protocol TCP
real_server 192.168.17.177 3306 { --真实服务器ip和port
weight 3 --权重为3
notify_down /opt/mysql/mysql.sh --指定自杀脚本的路径
TCP_CHECK {
connect_timeout 10
nb_get_retry 3
delay_before_retry 3
connect_port 3306
}
}
}
从端的配置文件大同小异，仅仅要把IP和实例名改成自己的就能够了，而且设置从端的priority为90，而主端为100
有一点要注意的是，主从两端的state，都配置成了backup，由于使用了nopreempt，即非抢占模式
举个样例，当主端先启动mysql实例和keepalived后，假设此时从端也启动了mysql实例和keepalived。那么vip不会跳到从端上去。即使它的优先级为100。要大于主端的90
而假设不设置nopreempt。那么这个时候。又分2种情况：
1.state同样，即都是master或都是backup
优先级高的，会占有vip。和角色无关
2.state不同。即master->backup或backup->master
优先级高的。会占有vip，和角色无关
前提不同。结果都是一样的，即优先级是主导，谁的优先级高。vip就漂到谁那里
创建一个自杀脚本来推断mysql进程是否启动
touch /opt/mysql/mysql.sh
加入下面内容：
#!/bin.sh
pkill keepalived --表示kill掉keepalived进程
三、执行測试
-f 指定keepalived的參数文件
-D 表示在操作系统日志里显示具体记录
推断keepalived进程是否正常启动，仅仅要查看/var/log/messages里的日志就能够了
tail -30f /var/log/message
注意。假设没有启动mysql而先启动了keepalived。那么之前notify_down參数中指定的脚本就会被运行，表示没有找到mysql进程，把keeplied自己的进程给kill掉。
Jul 25 02:51:22 zlm188 Keepalived[3440]: Starting Keepalived v1.2.13 (07/22,2014)
Jul 25 02:51:22 zlm188 Keepalived[3441]: Starting Healthcheck child process, pid=3442
Jul 25 02:51:22 zlm188 Keepalived[3441]: Starting VRRP child process, pid=3443
Jul 25 02:51:22 zlm188 Keepalived_vrrp[3443]: Netlink reflector reports IP 192.168.17.188 added
Jul 25 02:51:22 zlm188 Keepalived_healthcheckers[3442]: Netlink reflector reports IP 192.168.17.188 added
Jul 25 02:51:22 zlm188 Keepalived_healthcheckers[3442]: Netlink reflector reports IP fe80::a00:27ff:fe71:6b7b added
Jul 25 02:51:22 zlm188 Keepalived_healthcheckers[3442]: Registering Kernel netlink reflector
Jul 25 02:51:22 zlm188 Keepalived_vrrp[3443]: Netlink reflector reports IP fe80::a00:27ff:fe71:6b7b added
Jul 25 02:51:22 zlm188 Keepalived_healthcheckers[3442]: Registering Kernel netlink command channel
Jul 25 02:51:22 zlm188 Keepalived_vrrp[3443]: Registering Kernel netlink reflector
Jul 25 02:51:22 zlm188 Keepalived_vrrp[3443]: Registering Kernel netlink command channel
Jul 25 02:51:22 zlm188 Keepalived_vrrp[3443]: Registering gratuitous ARP shared channel
Jul 25 02:51:22 zlm188 Keepalived_vrrp[3443]: Opening file '/usr/local/keepalived/etc/keepalived/keepalived.conf'.
Jul 25 02:51:22 zlm188 Keepalived_healthcheckers[3442]: Opening file '/usr/local/keepalived/etc/keepalived/keepalived.conf'.
Jul 25 02:51:22 zlm188 Keepalived_healthcheckers[3442]: Configuration is using : 11566 Bytes
Jul 25 02:51:22 zlm188 Keepalived_vrrp[3443]: Configuration is using : 62964 Bytes
Jul 25 02:51:22 zlm188 Keepalived_vrrp[3443]: Using LinkWatch kernel netlink reflector...
Jul 25 02:51:22 zlm188 Keepalived_vrrp[3443]: VRRP_Instance(my_178) Entering BACKUP STATE
Jul 25 02:51:22 zlm188 Keepalived_vrrp[3443]: VRRP sockpool: [ifindex(2), proto(112), unicast(0), fd(10,11)]
Jul 25 02:51:22 zlm188 Keepalived_healthcheckers[3442]: Using LinkWatch kernel netlink reflector...
Jul 25 02:51:22 zlm188 Keepalived_healthcheckers[3442]: Activating healthchecker for service [192.168.17.188]:3306
Jul 25 02:51:25 zlm188 Keepalived_healthcheckers[3442]: TCP connection to [192.168.17.188]:3306 failed !!!
Jul 25 02:51:25 zlm188 Keepalived_healthcheckers[3442]: Removing service [192.168.17.188]:3306 from VS [192.168.17.166]:3306
Jul 25 02:51:25 zlm188 Keepalived_healthcheckers[3442]: Executing [/opt/mysql/mysql.sh] for service [192.168.17.188]:3306 in VS [192.168.17.166]:3306
Jul 25 02:51:25 zlm188 Keepalived_healthcheckers[3442]: Lost quorum 1-0=1 > 0 for VS [192.168.17.166]:3306
Jul 25 02:51:25 zlm188 Keepalived[3441]: Stopping Keepalived v1.2.13 (07/22,2014)
在从端启动keepalived，跟踪日志文件能够发现，跑了一遍以后自己主动stopping了。这也说明。之前的配置是ok的了，否则就要检查一下。哪里配置有误，尤其要注意virtual_route_id必须保持一致，而route_id则不强行要求一致。实例名也不要反复
1.检验vip的情况
#ip address show或ip a show
2.用vip登录mysql数据库(前提是已开启了mysqld和keepalived进程)
#mysql -h192.168.17.166 -uaaron8219 -pzlm
3.关闭某一端网卡后，測试vip的去向。以及能否通过vip正常登陆
#ifdown eth0
#ip a show
#mysql -h192.168.17.166 -uaaron8219 -pzlm
4.重新启动某一端(主机模拟主机故障)，測试vip的去向，以及能否通过vip正常登陆
#init 6
#ip a show
#mysql -h192.168.17.166 -uaaron8219 -pzlm
5.直接kill掉keepalived进程。測试vip的去向，以及能否通过vip正常登陆
#pkill keepalived
#ip a show
#mysql -h192.168.17.166 -uaaron8219 -pzlm
四、配置数据库同步
1.两端配置同步所需參数
确保server-id与slave不一致，通常server-id的格式能够设置成ip末尾2-3位+port号
比方我的环境master的ip是192.168.17.177，port是3306
那么server-id能够设置成1773306，对应地。slave就设置成1883306
下面參数都是在/etc/my.cnf文件里配置
server-id=1773306
log-bin=percona-bin --启用binlog
set-variable=binlog-ignore-db=mysql --不记录数据库mysql的更新日志，避免了Master上的权限设置等被同步到Slave上
2.两端加入复制用户
mysql> grant repliecation slave on *.* to 'rep'@'192.168.17.%' identified by 'rep';
假设想要在Slave上有权限运行 "LOAD TABLE FROM MASTER" 或 "LOAD DATA FROM MASTER" 语句的话，必须授予全局的 FILE 和 Select 权限：
mysql> GRANT FILE,Select,REPLICATION SLAVE ON *.* TO 'rep'@'%' IDENTIFIED BY 'rep';
3.设置同步
假设是新库，两边直接重置master的binlog
mysql> reset master;
(否则，须要把master的库用mysqldump导出（或直接打包压缩）。再拷贝到从库主机，大致过程例如以下：
①mysql> flush tables with read lock;
②mysql> mysqldump -uroot -p --all-databases -l -F >full_db.sql
scp full_db.sql root@192.168.17.188:/data/mysql/percona_3306/data
或
②cd /data/mysql/percona_3306
tar zcvf data.tar.gz ./data
scp data.tar.gz root@192.168.17.188
③mysql> unlock tables;
从库导入主库的数据库
mysql> mysql -uroot -p </data/mysql/percona_3306/data/full_db.sql
或
mysql> source /data/mysql/percona_3306/data/full_db.sql
)
4.主库查询日志状态
mysql> show master statusG
5.从库依据主库的binlog位置和position来运行同步
mysql> change master to master_host='192.168.17.177',master_user='rep',master_password='rep',
master_log_file='percona-bin.000001',master_log_pos='120';
6.启动slave
mysql> start slave;
启动后报错
Slave I/O: Fatal error: The slave I/O thread stops because master and slave have equal MySQL server UUIDs; these UUIDs must be different for replication to work. Error_code: 1593
由于从库是直接通过虚拟机拷贝镜像的方式创建的。所以UUID反复了，UUID是存放在
/data/mysql/percona_3306/data/auto.cnf文件里的
能够把这个文件直接删除。或者编辑该文件，改动里面的UUID和主库不同就可以，正常以后。应该是下面的状态：
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.17.177
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: percona-bin.000011
Read_Master_Log_Pos: 540
Relay_Log_File: node78-relay-bin.000018
Relay_Log_Pos: 285
Relay_Master_Log_File: percona-bin.000011
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:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 540
Relay_Log_Space: 459
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: 773306
Master_UUID: 917ecbfc-10dc-11e4-b624-080027267b03
Master_Info_File: /data/mysql/percona_3306/data/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Slave has read all relay log; waiting for the slave I/O thread to update it
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set:
Auto_Position: 0
7.測试
主库測试数据库zlm的tb_zlm表中运行插入一行数据：
(testing)root@localhost [(none)]> select * from zlm.tb_zlm;
+------+-----------+
| id | name |
+------+-----------+
| 1 | aaron8219 |
| 2 | zlm |
| 3 | abc |
+------+-----------+
3 rows in set (0.00 sec)
(testing)root@localhost [(none)]> insert into zlm.tb_zlm values(4,'def');
Query OK, 1 row affected (0.03 sec)
从库查询zlm.tb_zlm表：
(testing)root@localhost [(none)]> select * from zlm.tb_zlm;
+------+-----------+
| id | name |
+------+-----------+
| 1 | aaron8219 |
| 2 | zlm |
| 3 | abc |
| 4 | def |
+------+-----------+
4 rows in set (0.00 sec)
从库上也进行相同的配置，就可以完毕互为主从，仅仅要从对应的master的binlog的pos位置開始change maseter就能够了
结论：仅仅要配置的VRRP组里面有一台机器开启了mysqld和keepalived进程，不论什么通过vip实现的数据库连接訪问，都是正常的。这样不管是哪个节点down掉了，都不会影响mysql数据库的可用性，是一个最简单的mysql高可用架构。自此，通过keepalived来实现互为主从的双机热备架构就完毕了，假设再复杂一点。安装lvpsadm来实现虚拟server的配置，那么就是一个经典的keepalived+lvs架构