MySQL高可用性 —— keepalived HA mysql集群（双主）

准备环境
安装MySQL
配置主从
安装keepalived

准备环境

两台安装了CentOS7的主机官网下载

虚拟机也可以

MySQL离线包官网下载

mysql-8.0.12-linux-glibc2.12-x86_64.tar.xz

安装MySQL

解压MySQL到目录/usr/local/bin

tar –xvf mysql-8.0.12-linux-glibc2.12-x86_64.tar.xz

添加环境变量

vim /etc/profile
export MYSQL_PATH=/usr/local/bin/mysql-8.0.12-linux-glibc2.12-x86_64
export PATH=${MYSQL_PATH}/bin:$PATH
source /etc/profile

修改配置文件 /etc/my.cnf

[mysql_safe]一栏是为集群部署准备的配置
log-error 错误日志路径，需要自己事先新建${MYSQL_PATH}/log/error.log。如果不需要，请删除这一项配置，否则安装不成功。

初始化MySQL，切记拷贝好初始密码

${MYSQL_PATH}/bin/mysqld --initialize --user=xiaoming

添加MySQL服务，并设置成开机启动

cp ${MYSQL_PATH}/support-files/mysql.server /etc/init.d/mysql
chkconfig --add mysql
service mysql start

登录MySQL，修改密码

mysql -uroot -p
alter user \'root\'@\'localhost\' identified with mysql_native_password by \'123456\'

创建通用用户，赋予权限

create user \'root\'@\'%\' identified by \'123456\'
alter user \'root\'@\'%\' identified with mysql_native_password by \'123456\'
grant all privileges on *.* to \'root\'@\'%\' with grant option
flush privileges

配置主从

在另一台主机上安装MySQL，步骤如上，并修改配置文件

注意server_id和auto-increment-offset配置

登录MySQL，配置两个MySQL互为主从

show master status;
change master to master_host="192.168.9.57", master_user="root", master_port=3306, master_password="123456", master_log_file="binlog.000001", master_log_pos=155
start slave;
show slave status \G

show master status;
change master to master_host="192.168.9.58", master_user="root", master_port=3306, master_password="123456", master_log_file="binlog.000001", master_log_pos=155
start slave;
show slave status \G

注意master_host
注意master_log_file和master_log_pos，并不是每个MySQL服务安装后都会是一样的值，通过show master status可以查看

几个可选的MySQL调优参数

skip-name-resolve
innodb_write_io_threads=8
innodb_read_io_threads=8
max_connections=1024
mysqlx_max_connections=1024
slow_query_log=1
long_query_time=1
log_bin_trust_function_creators=1
max_allowed_packet=128M
read_buffer_size=8M
read_rnd_buffer_size=8M
sort_buffer_size=8M
innodb_buffer_pool_size=3G
innodb_buffer_pool_instances=8

重启MySQL

service mysql restart

安装keepalived

官网下载

keepalived-2.0.7.tar.gz

离线安装

# 解压安装包
tar –zxvf keepalived-2.0.7.tar.gz

# 配置安装地址
./configure –prefix=/usr/local/bin/keepalived/svr

# 离线安装示例：openssl-devel 
rpm –ivh openssl-devel-1.0.2k-12.el7.x86_64.rpm

# 安装
make && make install

其他离线包

配置keepalived开机启动

# 拷贝启动文件和配置文件
cp /usr/local/bin/keepalived/keepalived-2.0.7/keepalived/etc/init.d/keepalived /etc/init.d/
cp /usr/local/bin/keepalived/svr/etc/keepalived/keepalived.conf /etc/keepalived/
cp /usr/local/bin/keepalived/keepalived-2.0.7/keepalived/etc/sysconfig/keepalived /etc/sysconfig/

# 添加开机启动服务
chkconfig –add keepalived

修改配置文件

注意注释掉vrrp_strict，否则会导致虚拟IP无法PING通

编写上图中mysql.sh脚本

# 赋予脚本可执行权限
chmod +x /etc/keepalived/bin/mysql.sh

# 启动keepalived
service keepalived start

# 重启网络
service network restart

查看服务器虚拟IP信息：

ip addr show dev ens33

修改mysql启动脚本

vim /etc/init.d/mysql

另一台主机上的配置大同小异

# 选择master优先级
priority 50 

# 真实服务地址
real_server 192.168.9.58 3306