MySQL 双主 + keepalived 实现 HA

2个节点 (互为主从)

1、MySQLSrv1  192.168.1.41  (MySQL主从节点)

2、MySQLSrv2  192.168.1.42  (MySQL主从节点)

VIP: 192.168.1.47

软件版本说明：

1、操作系统  CentOS6.6_x86_64

2、MySQLServer  5.6.33

一、部署MySQL主从复制

1、用户及相关目录创建

--MySQLSrv1 节点

[root@mysqlsrv1 ~]# groupadd mysql

[root@mysqlsrv1 ~]# useradd mysql -g mysql

[root@mysqlsrv1 ~]# mkdir -p /opt/mysql

[root@mysqlsrv1 ~]# mkdir /mytmp

[root@mysqlsrv1 ~]# passwd mysql

--MySQLSrv2 节点

[root@mysqlsrv2 ~]# groupadd mysql

[root@mysqlsrv2 ~]# useradd mysql -g mysql

[root@mysqlsrv2 ~]# mkdir -p /opt/mysql

[root@mysqlsrv2 ~]# mkdir /mytmp

[root@mysqlsrv2 ~]# passwd mysql

安装依赖程序包 libaio

[root@mysqlsrv1 mytmp]# yum install libaio*

[root@mysqlsrv2 mytmp]# yum install libaio*

2、设置用户操作系统资源的限制

--以避免在启动mysql服务是会报：

2017-04-11 17:27:03 3175 [Warning] Buffered warning: Changed limits: max_open_files: 1024 (requested 5000)

2017-04-11 17:27:03 3175 [Warning] Buffered warning: Changed limits: table_open_cache: 431 (requested 2000)

之类的警告信息

[root@mysqlsrv1 ~]# vi /etc/security/limits.conf

在文件的最后添加如下内容

mysql soft nproc 2047

mysql hard nproc 16384

mysql soft nofile 1024

mysql hard nofile 65535

3、解压上传的二进制安装包程序并复制到目标目录下

--MySQLSrv1 节点

[root@mysqlsrv1 mytmp]# tar -xzvf mysql-5.6.33-linux-glibc2.5-x86_64.tar.gz

[root@mysqlsrv1 mytmp]# mv mysql-5.6.33-linux-glibc2.5-x86_64 /opt/mysql/3306

--MySQLSrv2 节点

[root@mysqlsrv2 mytmp]# tar -xzvf mysql-5.6.33-linux-glibc2.5-x86_64.tar.gz

[root@mysqlsrv2 mytmp]# mv mysql-5.6.33-linux-glibc2.5-x86_64 /opt/mysql/3306

4、便于方便管理创建单独的日志文件存放目录

--MySQLSrv1 节点

[root@mysqlsrv1 3306]# mkdir logs

--MySQLSrv2 节点

[root@mysqlsrv2 3306]# mkdir logs

5、数据库初始化安装

--MySQLSrv1 节点

[root@mysqlsrv1 ~]# cd /opt/mysql/3306

[root@mysqlsrv1 3306]# scripts/mysql_install_db --user=mysql --basedir=/opt/mysql/3306 --datadir=/opt/mysql/3306/data

--MySQLSrv2 节点

[root@mysqlsrv2 ~]$ cd /opt/mysql/3306

[root@mysqlsrv2 3306]$ scripts/mysql_install_db --user=mysql --basedir=/opt/mysql/3306 --datadir=/opt/mysql/3306/data

6、目录权限修改

--MySQLSrv1 节点

[root@mysqlsrv1 ~]# chown -R mysql:mysql /opt/mysql

--MySQLSrv2 节点

[root@mysqlsrv2 ~]# chown -R mysql:mysql /opt/mysql

注：1、为了使用方便创建mysql用户环境变量，如下所示：

   [mysql@mysqlsrv1 ~]$ vi ./.bash_profile

   添加如下内容：

   MYSQL3306_HOME=/opt/mysql/3306

   PATH=$PATH:$MYSQL3306_HOME/bin

   export MYSQL3306_HOME PATH

   [mysql@mysqlsrv2 ~]$ vi ./.bash_profile

   添加如下内容：

   MYSQL3306_HOME=/opt/mysql/3306

   PATH=$PATH:$MYSQL3306_HOME/bin

   export MYSQL3306_HOME PATH

7、参数文件配置

--MySQLSrv1 节点  

[mysql@mysqlsrv1 ~]$ vi /opt/mysql/3306/my.cnf

[client]

default_character_set = utf8

port = 3306

socket = /tmp/mysql3306.sock

[mysqld]

basedir = /opt/mysql/3306

datadir = /opt/mysql/3306/data

user = mysql

port = 3306

server_id = 13306

character_set_server = utf8

socket = /tmp/mysql3306.sock

pid-file = /tmp/mysql3306.pid

log-bin = /opt/mysql/3306/logs/bin_log

relay-log = /opt/mysql/3306/logs/relay_log

log-error = /opt/mysql/3306/logs/mysql_error.log

explicit_defaults_for_timestamp = true

expire_logs_days = 10

max_binlog_size = 100M

binlog-do-db = testdb   #复制数据库名称

binlog-ignore-db = mysql

slave-skip-errors = all

auto-increment-increment = 2

auto-increment-offset = 1

--MySQLSrv2 节点

[mysql@mysqlsrv2 ~]$ vi /opt/mysql/3306/my.cnf

[client]

default_character_set = utf8

port = 3306

socket = /tmp/mysql3306.sock

[mysqld]

basedir = /opt/mysql/3306

datadir = /opt/mysql/3306/data

user = mysql

port = 3306

server_id = 23306

character_set_server = utf8

socket = /tmp/mysql3306.sock

pid-file = /tmp/mysql3306.pid

log-bin = /opt/mysql/3306/logs/bin_log

relay-log = /opt/mysql/3306/logs/relay_log

log-error = /opt/mysql/3306/logs/mysql_error.log

explicit_defaults_for_timestamp = true

expire_logs_days = 10

max_binlog_size = 100M

binlog-do-db = testdb   #复制数据库名称

binlog-ignore-db = mysql

slave-skip-errors = all

auto-increment-increment = 2

auto-increment-offset = 2

8、清理配置参数文件

在Linux平台下，mysql程序默认会按照以下顺序扫描路径寻找配置文件

/etc/my.cnf

/etc/mysql/my.cnf

SYSCONFDIR/my.cnf   #通过CMake源代码编译时指定的SYSCONFDIR的参数指定的路径

$MYSQL3306_HOME/my.cnf  #MYSQL_HOME环境变量所在路径，即mysql安装路径(basedir)

~/.my.cnf  #~表示到当更前用户根目录下寻找

通过命令(root用户只需查询)  find  /  -iname  my.cnf  查询配置文件的存在性，仅保留 MYSQL3306_HOME/my.cnf 配置文件。

注：使用如下命令可查看mysql实例的配置文件搜索顺序

[root@mysqlsrv1 bin]# mysql --help | grep '/my.cnf'

9、配置启动脚本

--MySQLSrv1 节点实例

[root@mysqlsrv1 3306]# cp support-files/mysql.server /etc/init.d/mysql3306

[root@mysqlsrv1 3306]# vi /etc/init.d/mysql3306

将如下内容

#basedir=...

#datadir=...

修改为：

basedir=/opt/mysql/3306

datadir=/opt/mysql/3306/data

--MySQLSrv2 节点实例

[root@mysqlsrv2 3306]# cp support-files/mysql.server /etc/init.d/mysql3306

[root@mysqlsrv2 3306]# vi /etc/init.d/mysql3306

将如下内容

#basedir=...

#datadir=...

修改为：

basedir=/opt/mysql/3306

datadir=/opt/mysql/3306/data

10、数据库服务启动

--MySQLSrv1 节点

[mysql@mysqlsrv1 ~]$ service  mysql3306  start

--MySQLSrv2 节点

[mysql@mysqlsrv2 ~]$ service  mysql3306  start

注：启动若报如下错误

Starting MySQL.2017-04-13T07:19:57.334037Z mysqld_safe The file /usr/local/mysql/bin/mysqld

does not exist or is not executable. Please cd to the mysql installation

directory and restart this script from there as follows:

./bin/mysqld_safe&

See http://dev.mysql.com/doc/mysql/en/mysqld-safe.html for more information

ERROR! The server quit without updating PID file (/tmp/mysql3306.pid).

解决方法：

[root@mysqlsrv1 ~]# mkdir -p /usr/local/mysql/bin

[root@mysqlsrv1 ~]# ln -s /opt/mysql/3306/bin/mysqld /usr/local/mysql/bin/mysqld

[root@mysqlsrv2 ~]# mkdir -p /usr/local/mysql/bin

[root@mysqlsrv2 ~]# ln -s /opt/mysql/3306/bin/mysqld /usr/local/mysql/bin/mysqld

11、登录数据库以添加远程登录帐号信息

[mysql@mysqlsrv1 ~]$ mysql -u root -p  -P 3306 --socket=/tmp/mysql3306.sock

[mysql@mysqlsrv2 ~]$ mysql -u root -p  -P 3306 --socket=/tmp/mysql3306.sock

注：使用mysql用户执行上述命令前，先配置相关环境变量值

/home/mysql/.bash_profile

添加如下内容：

MYSQL3306_HOME=/opt/mysql/3306

PATH=$PATH:$MYSQL3306_HOME/bin

export MYSQL3306_HOME PATH

注：上述登录数据库是需有参数  --socket ,否则会报出如下错误:

Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock

--为了安全起见，先删除默认生成的用户相关信息在创建一个指定名称的数据库管理员帐号

mysql> use mysql;

mysql> delete from db;

mysql> delete from user;

mysql> grant all privileges on *.* to 'sysadmin'@'localhost' identified by 'mysql' with grant option;

mysql> grant all privileges on *.* to 'sysadmin'@'127.0.0.1' identified by 'mysql' with grant option;

mysql> flush privileges;

mysql> select host,user from user where user='sysadmin';

12、在两个节点创建复制专用帐号

mysql> grant replication slave on *.* to 'repl'@'%' identified by 'repl';

Query OK, 0 rows affected (0.01 sec)

mysql> flush privileges;

Query OK, 0 rows affected (0.00 sec)

13、查看 master 主机信息

[mysql@mysqlsrv1 ~]$ mysql -u sysadmin -p -P 3306 -S /tmp/mysql3306.sock

mysql> show master status \G

*************************** 1. row ***************************

                       File: bin_log.000002

               Position: 120

     Binlog_Do_DB: testdb

Binlog_Ignore_DB: mysql

Executed_Gtid_Set:

1 row in set (0.00 sec)

mysql>

[mysql@mysqlsrv2 ~]$ mysql -u sysadmin -p -P 3306 -S /tmp/mysql3306.sock

mysql> show master status \G

*************************** 1. row ***************************

                       File: bin_log.000002

               Position: 120

     Binlog_Do_DB: testdb

Binlog_Ignore_DB: mysql

Executed_Gtid_Set:

1 row in set (0.00 sec)

mysql>

14、配置两个节点之间互为主从角色，并启动复制

--MySQLSrv1 节点

[mysql@mysqlsrv1 ~]$ mysql -u sysadmin -p -P 3306 -S /tmp/mysql3306.sock

mysql> show slave status \G

Empty set (0.00 sec)

mysql> change master to

   -> master_host='192.168.1.42',

   -> master_port=3306,

   -> master_user='repl',

   -> master_password='repl',

   -> master_log_file='bin_log.000002',

   -> master_log_pos=120;

Query OK, 0 rows affected, 2 warnings (0.06 sec)

mysql> start slave;

Query OK, 0 rows affected (0.17 sec)

mysql>

--MySQLSrv2 节点

[mysql@mysqlsrv2 ~]$ mysql -u sysadmin -p -P 3306 -S /tmp/mysql3306.sock

mysql> show slave status \G

Empty set (0.00 sec)

mysql> change master to

   -> master_host='192.168.1.41',

   -> master_port=3306,

   -> master_user='repl',

   -> master_password='repl',

   -> master_log_file='bin_log.000002',

   -> master_log_pos=120;

Query OK, 0 rows affected, 2 warnings (0.06 sec)

mysql> start slave;

Query OK, 0 rows affected (0.17 sec)

mysql>

15、复制功能测试

--MySQLSrv1 节点

mysql> create database testdb;

mysql> use testdb;

Database changed

mysql> select database();

+------------+

| database() |

+------------+

| testdb |

+------------+

1 row in set (0.00 sec)

--MySQLSrv2 节点

mysql> use testdb;

mysql> create table t1(id int, name varchar(20));

Query OK, 0 rows affected (1.71 sec)

mysql> select * from t1;

Empty set (0.00 sec)

--MySQLSrv1 节点

mysql> insert into t1 (id,name) values(1,'重庆');

Query OK, 1 row affected (0.00 sec)

mysql> select * from t1;

+------+----------+

| id | name |

+------+----------+

| 1 | 重庆 |

--MySQLSrv2 节点

mysql> select * from t1;

Empty set (0.01 sec)

mysql> select * from t1;

+------+----------+

| id | name |

+------+----------+

| 1 | 重庆 |

+------+----------+

1 row in set (0.00 sec)

mysql>

-------------- 两个节点之间的互为主从的复制功能正常 ---------------------------

二、部署keepalived服务

1、安装程序文件

[root@mysqlsrv1 ~]#  yum install keepalived

[root@mysqlsrv2 ~]#  yum install keepalived

注：

配置文件  /etc/keepalived/keepalived.conf

日志文件  /var/log/messages

2、修改配置文件内容

--MySQLSrv1 节点

global_defs {

notification_email {

[email protected]

}

notification_email_from  [email protected]

smtp_server 127.0.0.1

smtp_connect_timeout 30

router_id MYSQL_HA      #标识，双主相同

}

vrrp_instance VI_1 {

state BACKUP          #两台都设置BACKUP

interface eth0

virtual_router_id 51      #主备相同

priority 100          #优先级，backup设置90

advert_int 1

nopreempt            #不主动抢占资源，只在master这台优先级高的设置，backup不设置

authentication {

auth_type PASS

auth_pass 1111

}

virtual_ipaddress {

192.168.1.47

}

}

virtual_server 192.168.1.41 3306 {

delay_loop 2

#lb_algo rr              #LVS算法，用不到，我们就关闭了

#lb_kind DR              #LVS模式，如果不关闭，备用服务器不能通过VIP连接主MySQL

persistence_timeout 50  #同一IP的连接60秒内被分配到同一台真实服务器

protocol TCP

real_server 192.168.1.41 3306 {  #检测本地mysql，backup也要写检测本地mysql

weight 3

notify_down /usr/local/keepalived/mysql_check.sh    #当mysq服down时，执行此脚本，杀死keepalived实现切换

TCP_CHECK {

connect_timeout 3    #连接超时

nb_get_retry 3      #重试次数

delay_before_retry 3 #重试间隔时间

 }

}

--MySQLSrv2 节点

global_defs {

notification_email {

[email protected]

}

notification_email_from  [email protected]

smtp_server 127.0.0.1

smtp_connect_timeout 30

router_id MYSQL_HA      #标识，双主相同

}

vrrp_instance VI_1 {

state BACKUP          #两台都设置BACKUP

interface eth0

virtual_router_id 51      #主备相同

priority 90          #优先级，backup设置90

advert_int 1

#nopreempt            #不主动抢占资源，只在master这台优先级高的设置，backup不设置

authentication {

auth_type PASS

auth_pass 1111

}

virtual_ipaddress {

192.168.1.47

}

}

virtual_server 192.168.1.42 3306 {

delay_loop 2

#lb_algo rr              #LVS算法，用不到，我们就关闭了

#lb_kind DR              #LVS模式，如果不关闭，备用服务器不能通过VIP连接主MySQL

persistence_timeout 50  #同一IP的连接60秒内被分配到同一台真实服务器

protocol TCP

real_server 192.168.1.42 3306 {  #检测本地mysql，backup也要写检测本地mysql

weight 3

notify_down /usr/local/keepalived/mysql_check.sh    #当mysq服down时，执行此脚本，杀死keepalived实现切换

TCP_CHECK {

connect_timeout 3    #连接超时

nb_get_retry 3      #重试次数

delay_before_retry 3 #重试间隔时间

 }

}

--mysql_check.sh 文件(两个节点相同)

#!/bin/bash

pkill keepalived

3、创建测试用户：

MySQLSrv1 节点

mysql  -u  sysadmin  -p  -P 3306  -S  /tmp/mysql3306.sock

mysql> grant all privileges on *.* to 'yangchao'@'%' identified by 'yangchao';

mysql> flush privileges;

4、keepalived 测试

启动 MySQLSrv1 节点 keepalived 服务

[root@mysqlsrv1 ~]# service  keepalived  start

启动 MySQLSrv2 节点 keepalived 服务

[root@mysqlsrv2 ~]# service  keepalived  start

在 MySQLSrv1 节点查看VIP

在 MySQLSrv2 节点查看VIP

由上测试可知, keepalived 成功在节点 MySQLSrv1 上绑定VIP 192.168.1.47

在 MySQLSrv1 节点重新启动 keepalived 服务：

由上测试可知，keepalived 服务绑定的IP地址成功漂移到 MySQLSrv2 节点。

5、MySQL 服务测试

--在 MySQLSrv1 节点登录

由上测试可知，虽然在 MySQLSrv1 节点登录，但登录到的节点是VIP实际绑定的 MySQLSrv2 节点。

插入数据：

在 MySQLSrv2 节点上停止 mysql 服务

停止mysql服务后，自动停止了所在节点的keepalived服务。

在 MySQLSrv1 节点查看

keepalived 服务成功漂移到 MySQLSrv1 节点。