MySQL双主-高可用
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单台数据库实例安装
请参考:二进制包安装MySQL
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资源规划
主机名 |
os 版本 |
MySQL 版本 |
主机 IP |
MySQL VIP |
db01.lyk.com |
centos 6.4 |
mysql-5.6.21-linux-glibc2.5-x86_64 |
172.31.30.12 |
172.31.30.222 |
db02.lyk.com |
centos 6.4 | mysql-5.6.21-linux-glibc2.5-x86_64 | 172.31.30.11 |
3.修改MySQL配置文件
修改DB01的配置文件:
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vi
/etc/my
.cnf
#在[mysqld]添加如下内容#
server-
id
= 100
log-bin =
/usr/local/mysql/data/ttpai-bin
binlog_format = MIXED
#非必需
relay-log =
/usr/local/mysql/data/ttpai-relay-bin
binlog-ignore-db = mysql
binlog-ignore-db =
test
binlog-ignore-db = information_schema
binlog-ignore-db = performance_schema
replicate-wild-ignore-table = mysql.%
replicate-wild-ignore-table =
test
.%
replicate-wild-ignore-table = information_schema.%
replicate-wild-ignore-table = performance_schema.%
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修改DB02的配置文件:
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vi
/etc/my
.cnf
#在[mysqld]添加如下内容#
server-
id
= 110
log-bin =
/usr/local/mysql/data/ttpai-bin
binlog_format = MIXED
#非必需
relay-log =
/usr/local/mysql/data/ttpai-relay-bin
binlog-ignore-db = mysql
binlog-ignore-db =
test
binlog-ignore-db = information_schema
binlog-ignore-db = performance_schema
replicate-wild-ignore-table = mysql.%
replicate-wild-ignore-table =
test
.%
replicate-wild-ignore-table = information_schema.%
replicate-wild-ignore-table = performance_schema.%
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4.手动同步数据库
如果DB01上已经有MySQL数据,那么执行主主互备之前,需要将DB01和DB02上的两个MySQL的数据保持同步,首先在DB01上备份MySQL数据,执行如下SQL:
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mysql> FLUSH TABLES
WITH
READ
LOCK;
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在不退出终端的情况下(推出锁失效),再开启一个session,直接打包MySQL的数据文件或者mysqldump工具导出:
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cd
/usr/local/mysql/
tar
zcvf data.
tar
.gz data/
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将data.tar.gz 传输到DB02,依次重启DB01和DB02。
其实,可以在不执行READ LOCK语句,直接使用mysqldump语句备份,最起码个人测试是数据不会丢失或者说出现同步异常。使用如下命令:
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mysqldump --default-character-
set
=gbk --opt --triggers -R -E --hex-blob --single-transaction --master-data=2 ttpai > ttpai.sql
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其中--master-data=2可以锁定binlog的文件名及坐标。
5.创建授权复制用户
DB01执行:
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mysql> grant REPLICATION SLAVE ON *.* TO lyk@
'172.31.30.11'
IDENTIFIED BY
'lyk123'
;
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DB02执行:
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mysql> grant REPLICATION SLAVE ON *.* TO lyk@
'172.31.30.12'
IDENTIFIED BY
'lyk123'
;
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其中关于坐标的值,可以执行如下SQL得到:
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mysql> show master status;
+------------------+-----------+--------------+--------------------------------------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+-----------+--------------+--------------------------------------------------+-------------------+
| ttpai-bin.000093 | 502389306 | | mysql,
test
,information_schema,performance_schema | |
+------------------+-----------+--------------+--------------------------------------------------+-------------------+
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如果使用mysqldump 可以使用如下命令:
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head
-n50 ttpai.sql
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6.启动互为主从的模式
在DB02上执行:
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mysql>CHANGE MASTER TO
MASTER_LOG_FILE=
'ttpai-bin.000050'
,
MASTER_LOG_POS=754861035,
MASTER_HOST=
'172.31.30.12'
,
MASTER_USER=
'lyk'
,
MASTER_PASSWORD=
'lyk123'
;
mysql>start slave;
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在DB01上执行:
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mysql>CHANGE MASTER TO
MASTER_LOG_FILE=
'ttpai-bin.000050'
,
MASTER_LOG_POS=754861035,
MASTER_HOST=
'172.31.30.12'
,
MASTER_USER=
'lyk'
,
MASTER_PASSWORD=
'lyk123'
;
mysql>start slave;
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验证同步结果:
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mysql>show slave status\G;
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自此Mysql互为主从已完毕。
7.安装lvs+keepalived
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yum instal keepalived ipvsadm
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8.编辑keepalived配置文件
DB01的配置文件:
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vi
/etc/keepalived/keepalived
.conf
global_defs {
notification_email {
sysadmin@lyk.com
}
notification_email_from monitor@lyk.com
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_Mysql
}
vrrp_instance HA_1 {
state BACKUP
interface bond0
virtual_router_id 80
priority 100
advert_int 2
nopreempt
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
172.31.30.222
}
}
virtual_server 172.31.30.222 3306 {
delay_loop 2
lb_algo wlc
lb_kind DR
nat_mask 255.255.255.0
protocol TCP
persistence_timeout 60
real_server 172.31.30.12 3306 {
weight 1
notify_down
/etc/keepalived/mysqlcheck/mysql
.sh
TCP_CHECK {
connect_port 3306
connect_timeout 3
nb_get_retry 2
delay_before_retry 1
}
}
}
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其中需要注意的是:
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state BACKUP #DB01和DB02均配置为BACKUP状态
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nopreempt #为不强占模式,DB02(slave)不用设置
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notify_down #定义监测realserver失败下一步的动作
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priority #DB02要比DB01低
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interface bond0 #没什么特别,却是我的整个搭建最耗时的痛点,稍后解释
创建notify_down的脚本(DB01和DB02都需创建):
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mkdir
-p
/etc/keepalived/mysqlcheck/
cd
/etc/keepalived/mysqlcheck/
vi
mysql.sh
#!/bin/sh
pkill keepalived
chmod
u+x mysql.sh
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其实就是干掉keepalived进程,释放VIP。
DB02的配置文件:
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global_defs {
notification_email {
sysadmin@lyk.com
}
notification_email_from monitor@lyk.com
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_Mysql
}
vrrp_instance HA_1 {
state BACKUP
interface bond0
virtual_router_id 80
priority 90
advert_int 2
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
172.31.30.222
}
}
virtual_server 172.31.30.222 3306 {
delay_loop 2
lb_algo wlc
lb_kind DR
nat_mask 255.255.255.0
protocol TCP
persistence_timeout 60
real_server 172.31.30.11 3306 {
weight 1
notify_down
/etc/keepalived/mysqlcheck/mysql
.sh
TCP_CHECK {
connect_port 3306
connect_timeout 3
nb_get_retry 2
delay_before_retry 1
}
}
}
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DB01和DB02的启动keepalived:
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/etc/init
.d
/keepalived
start
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9.测试
测试主从同步,通过VIP连接:
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mysql -h172.31.30.222 -utest -ptest ttpai
mysql> show vaiables like
'server_id'
;
#可以确认那台为master状态
mysql> create table ....
#到slave状态的数据库看都是否正常
.....
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测试keepalived实现MySQL故障转移:
可以在DB01执行
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/etc/init
.d
/mysqld
stop
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远程一直执行
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show vaiables like
'server_id'
;
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发现会卡1~3s,server_id变为110,即master变为DB02。
即使重启DB01,VIP也不会转移,因为采用的是不抢占模式,直到DB02的服务挂,才会转移VIP。
10:总结
来说下interface bond0的事儿:
一切配置都很顺,但是在测试的时候,发现VIP连接数据库,执行SQL时卡时不卡,在windows下ping VIP或者VIP所在的DB的主机IP,丢包;有没有蛋碎的感觉。开始一头雾水,后来仔细又看了一边lvs DR模式的原理,原来都和MAC地址相关联,而自己的环境网卡做了bond0(mode=0),却在交换机上没做端口聚合,可以认为网卡MAC发生紊乱。
解决:
配置交换机(H3C)
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#创建端口聚合组(不同型号,命令不同,叫法不一样)
interface Bridge-Aggregation2
description bonding
port access vlan 30
interface Bridge-Aggregation3
description bonding
port access vlan 30
#将做bonding的网卡加入对应的聚合组
interface GigabitEthernet1
/0/3
port access vlan 30
port link-aggregation group 3
......
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一切恢复正常,发生这个事件,不知是自己太低端,还是大家都没遇到,搜资料真没收到,呵呵。
注意:
LVS DR原理
bonding 模式的注意点