配置MySQL5.7基于GTID的双主复制 

 

一、       安装前规划

1.1   大体架构规划如下

Master1/Slave 192.168.9.71:3306

Master2/Slave 192.168.9.72:3306

数据库搭建过程请参考《mysql5.7部署文档》

二、       双主复制搭建

2.1 创建同步用户repl(master上)

grant replication slave on *.* to 'repl'@'%' identified by '123456';

flush privileges;

注：其中'repl'@'%'部分可以修改为'repl'@'xxx.xxx.xxx.*'或'repl'@'xxx.xxx.xxx.xxx'的形式，出于安全目的用以限制网段或IP访问（其中xxx为具体IP）

2.2 Master1 my.cnf添加同步参数

server_id=1

log-bin = /mysql/3306/binlog/bin.log #binlog存放路径,需要根据实际情况修改

log_bin_index = /mysql/3306/binlog/bin.index

max-binlog-size=209715200

expire-logs-days = 7

sync-binlog = 1

binlog_format="ROW"

log_bin_trust_function_creators = 1

binlog_cache_size = 2097152

上诉参数数据库搭建过程已经配置。

# replication settings #

gtid_mode = on

enforce_gtid_consistency = 1

log_slave_updates

master_info_repository = TABLE

relay_log_info_repository = TABLE

relay_log = /mysql/3306/binlog/relay.log

relay_log_index = /mysql/3306/binlog/relay_log.index

relay_log_purge = 1

relay_log_recovery = 1

report-port = 3306

report-host = 192.168.9.71

slave-rows-search-algorithms = 'INDEX_SCAN,HASH_SCAN'

# new replication settings #

slave-parallel-type = LOGICAL_CLOCK

slave-parallel-workers = 8

slave_preserve_commit_order=1

slave_transaction_retries=128

# auto-increment #

auto-increment-increment = 2

auto-increment-offset = 1

2.3 Master2 my.cnf添加同步参数

server_id=2

log-bin = /mysql/3306/binlog/bin.log #binlog存放路径,需要根据实际情况修改

log_bin_index = /mysql/3306/binlog/bin.index

max-binlog-size=209715200

expire-logs-days = 7

sync-binlog = 1

binlog_format="ROW"

log_bin_trust_function_creators = 1

binlog_cache_size = 2097152

上诉参数数据库搭建过程已经配置。

# replication settings #

gtid_mode = on

enforce_gtid_consistency = 1

log_slave_updates

master_info_repository = TABLE

relay_log_info_repository = TABLE

relay_log = /mysql/3306/binlog/relay.log

relay_log_index = /mysql/3306/binlog/relay_log.index

relay_log_purge = 1

relay_log_recovery = 1

report-port = 3306

report-host = 192.168.9.72

slave-rows-search-algorithms = 'INDEX_SCAN,HASH_SCAN'

# new replication settings #

slave-parallel-type = LOGICAL_CLOCK

slave-parallel-workers = 8

slave_preserve_commit_order=1

slave_transaction_retries=128

# auto-increment #

auto-increment-increment = 2

auto-increment-offset = 2

注：

1）   以上添加参数如已在my.cnf文件里则无需添加，其中主库server_id的数字不能和备库server_id相同，

一般一主一从架构中，备库server_id默认设为2即可

2）   log-slave-updates参数用来控制slave库是否把replication的event也写进binlog，如果是M->S1->S2的级联同步架构，则S1(第一个slave库)需要打开binlog和把log-slave-updates参数设为1

3）   auto_increment_increment 控制列中的值的增量值，也就是步长。

4）   auto_increment_offset 确定AUTO_INCREMENT列值的起点，也就是初始值。

在主主同步配置时，需要将两台服务器的：

auto_increment_offset        分别配置为1和2。这是序号，第一台从1开始，第二台就是2，以此类推.....

auto_increment_increment     增长量都配置为2

2.4  Master1备份与Master2导入

2.4.1         mysqldump备份

Master1备份:

mysqldump -uroot -p --single-transaction --default-character-set=utf8 --master-data=2 --flush-logs --triggers --routines --events  --all-databases > allDB.`hostname`_`date +"%Y%m%d%H%M"`.sql

Master2导入：

mysql> reset master;

Query OK, 0 rows affected (0.01 sec)

mysql -uroot -p < allDB.`hostname`_`date +"%Y%m%d%H%M"`.sql

2.4.2         配置同步

Master1配置同步参数

CHANGE MASTER TO

MASTER_HOST = '192.168.9.72',

MASTER_PORT = 3306,

MASTER_USER = 'repl',

MASTER_PASSWORD = '123456',

MASTER_AUTO_POSITION = 1;

Master2配置同步参数

CHANGE MASTER TO

MASTER_HOST = '192.168.9.71',

MASTER_PORT = 3306,

MASTER_USER = 'repl',

MASTER_PASSWORD = '123456',

MASTER_AUTO_POSITION = 1;

注:

master_host参数配置主库IP地址

master_port参数配置主库端口号

master_user参数配置主库的同步用户名

master_password参数配置主库同步用户的密码

2.4.3         开启同步并查看状态（两台主机分别执行）

mysql> start slave ;

Query OK, 0 rows affected (0.04 sec)

mysql> show slave status\G;

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

Slave_IO_State: Waiting for master to send event

Master_Host: 192.168.9.71

Master_User: repl

Master_Port: 3306

Connect_Retry: 60

Master_Log_File: bin.000004

Read_Master_Log_Pos: 194

Relay_Log_File: relay.000002

Relay_Log_Pos: 355

Relay_Master_Log_File: bin.000004

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: 194

Relay_Log_Space: 552

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

Master_UUID: 15c4b75c-cd03-11e9-be6b-080027364db6

Master_Info_File: mysql.slave_master_info

SQL_Delay: 0

SQL_Remaining_Delay: NULL

Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates

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: 15c4b75c-cd03-11e9-be6b-080027364db6:1-231665

Auto_Position: 1

Replicate_Rewrite_DB:

Channel_Name:

Master_TLS_Version:

1 row in set (0.00 sec)

ERROR:

No query specified

三、       使用Keepalived实现故障转移

3.1 Keepalived安装

1、下载安装包

http://www.keepalived.org/download.html Keepalived for Linux - Version 2.0.18

2、编译安装Keepalived

tar -zxvf keepalived-2.0.18.tar.gz cd keepalived-2.0.18 ./configure --prefix=/usr/local/keepalived make && make install

3、将Keepalived注册为系统服务

cp /usr/local/keepalived/sbin/keepalived /usr/sbin/ cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/ mkdir -p /etc/keepalived cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf cp /mysql/keepalived-2.0.18/keepalived/etc/init.d/keepalived /etc/init.d/keepalived

3.2 Keepalived配置，实现故障转移

备注：Keepalived使用vip 192.168.9.73实现故障转移。

Master1：/etc/keepalived/keepalived.conf

! Configuration File for keepalived global_defs { notification_email { figo@live.cn } notification_email_from luwenju@live.cn smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id MySQL-ha script_user root enable_script_security } vrrp_instance VI_1 { state BACKUP interface eth1 virtual_router_id 51 priority 100 advert_int 1 nopreempt authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.9.73 } } virtual_server 192.168.9.73 3306 { delay_loop 2 lb_algo wrr lb_kind DR persistence_timeout 60 protocol TCP real_server 192.168.9.71 3306 { weight 3 notify_down /usr/local/MySQL.sh TCP_CHECK { connect_timeout 10 nb_get_retry 3 delay_before_retry 3 connect_port 3306 } } }

Master2：/etc/keepalived/keepalived.conf

! Configuration File for keepalived global_defs { notification_email { figo@live.cn } notification_email_from luwenju@live.cn smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id MySQL-ha script_user root enable_script_security } vrrp_instance VI_1 { state BACKUP interface eth1 virtual_router_id 51 priority 90 advert_int 1 # nopreempt authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.9.73 } } virtual_server 192.168.9.73 3306 { delay_loop 2 lb_algo wrr lb_kind DR persistence_timeout 60 protocol TCP real_server 192.168.9.72 3306 { weight 3 notify_down /usr/local/MySQL.sh TCP_CHECK { connect_timeout 10 nb_get_retry 3 delay_before_retry 3 connect_port 3306 } } }

3.3 Keepalived依赖脚本

MySQL.sh 当mysql服务down时，执行此脚本，杀死keepalived实现切换

 

check_Mysql_KeepAlived.sh 是为了检查mysqld进程是否存活的脚本，当发现连接不上mysql，自动把keepalived进程杀死，让VIP进行漂移。或者mysqld存活时自动启动未启动的keepalived进程

 

[root@oracle12c local]# cat /usr/local/MySQL.sh #!/bin/sh pkill keepalived [root@oracle12c local]# cat /usr/local/check_Mysql_KeepAlived.sh #!/bin/bash log_dir=/mysql/check_log check_time=`date "+%Y-%m-%d %H:%M:%S"` log_time=`date +%F` log=$log_dir/check_${log_time}.log . /root/.bash_profile count=1 while true do mysql -uroot -p12345678 -S /var/lib/mysql/mysql.sock -e "show status;" > /dev/null 2>&1 i=$? ps aux | grep mysqld | grep -v grep > /dev/null 2>&1 j=$? if [ $i = 0 ] && [ $j = 0 ] then ps aux|grep keepalived|grep -v grep > /dev/null 2>&1 k=$? if [ $k = 1 ] then /etc/init.d/keepalived start > /dev/null 2>&1 echo "$check_time,service mysqld is running,keepalived not active,start keepalived.">>$log exit 0 else echo "$check_time,services are running.">>$log exit 0 fi else if [ $i = 1 ] && [ $j = 0 ] then exit 0 else if [ $count -gt 5 ] then ps aux|grep keepalived|grep -v grep > /dev/null 2>&1 rlk=$? if [ $rlk = 0 ] then pkill keepalived > /dev/null 2>&1 echo "$check_time,service mysqld is not active,keepalived shoud be closed.">>$log break else echo "$check_time,services are not active.">>$log break fi fi let count++ continue fi fi done

脚本部署完毕后，修改部分内容，赋执行权限并配置定时任务

chmod +x /usr/local/check_Mysql_KeepAlived.sh chmod +x /usr/local/MySQL.sh crontab -e */1 * * * * /usr/local/check_Mysql_KeepAlived.sh

3.4 故障转移测试

开启Keepslave进程

service keepalived start service keepalived status

检查状态

tail -f /var/log/messages ip a

先在服务器端授权远程连接：

mysql> grant all privileges on *.* to 'root'@'%' identified by '123456'; mysql> flush privileges;

然后在第三台服务器上用vip连接数据库：

mysql -uroot -p -h 192.168.9.73 mysql> show variables like '%host%'; +-------------------------------+--------+ | Variable_name                 | Value  | +-------------------------------+--------+ | host_cache_size               | 653    | | hostname                      | mysql4 | | performance_schema_hosts_size | 100    | | report_host                   |        | +-------------------------------+--------+

如果停止当前连接节点mysql4 mysql服务：

service mysqld stop Shutting down MySQL.............[  OK  ]

过一会儿查看目标连接：

mysql> show variables like '%host%'; +-------------------------------+--------+ | Variable_name                 | Value  | +-------------------------------+--------+ | host_cache_size               | 653    | | hostname                      | mysql3 | | performance_schema_hosts_size | 100    | | report_host                   |        | +-------------------------------+--------+ 4 rows in set (0.00 sec)

此时再开启mysql4上的mysql服务：

service mysqld start Starting MySQL...[  OK  ]

再次在客户端查看连接：

mysql> show variables like '%host%'; +-------------------------------+--------+ | Variable_name                 | Value  | +-------------------------------+--------+ | host_cache_size               | 653    | | hostname                      | mysql3 | | performance_schema_hosts_size | 100    | | report_host                   |        | +-------------------------------+--------+ 4 rows in set (0.00 sec)

四、       附录

4.1             keepalived.conf参数详解

global_defs {

notification_email {

figo@live.cn

}

notification_email_from  figo@live.cn

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 {

192.168.9.57

}

}

virtual_server 192.168.9.57 3306 {

delay_loop 2

lb_algo wrr    #LVS算法

lb_kind DR     #LVS模式

persistence_timeout 60   #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 192.168.9.55 3306 {  #检测本地mysql，backup也要写检测本地mysql

weight 3

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

TCP_CHECK {

connect_timeout 10

nb_get_retry 3         #连接超时

delay_before_retry 3   #重试次数

connect_port 3306      #重试间隔时间

}

}

}

4.2             遗留问题

1、  Keepalived脑裂问题解决思路。

2、  开启GTID双主同步后备份恢复注意事项。