通过Prometheus监控Mysql，我们需要在Mysql端安装一个mysql-exporter，然后Prometheus通过mysql-exporter暴露的端口抓取数据。

1.安装一个MYSQL

配置MYSQL源
echo '# Enable to use MySQL 5.7
[mysql57-community]
name=MySQL 5.7 Community Server
baseurl=http://repo.mysql.com/yum/mysql-5.7-community/el/7/$basearch/
enabled=1
gpgcheck=1
gpgkey=http://repo.mysql.com/RPM-GPG-KEY-mysql' >/etc/yum.repos.d/mysql.repo

安装mysql 5.7
yum install mysql-community-server -y

启动并设置开机启动
systemctl start mysqld.service
systemctl status mysqld.service
systemctl enable mysqld.service

查看mysql初始密码
grep 'temporary password' /var/log/mysqld.log
2021-01-22T01:30:46.703325Z 1 [Note] A temporary password is generated for root@localhost: k+F<ucNmR5sK

修改mysql root密码
su - mysql
mysql -uroot -p
ALTER USER 'root'@'localhost' IDENTIFIED BY 'zaq1@WSX';
flush privileges;
到这里mysql5.7安装完成。

2.登录mysql为exporter创建账号并授权

# 创建数据库用户。
mysql> CREATE USER 'exporter'@'localhost' IDENTIFIED BY 'zaq1@WSX';
# 可查看主从运行情况查看线程，及所有数据库。
mysql> GRANT PROCESS, REPLICATION CLIENT, SELECT ON *.* TO 'exporter'@'localhost';

3.下载mysql-exporter并做配置

1.下载mysql-exporter
wget https://github.com/prometheus/mysqld_exporter/releases/download/v0.12.1/mysqld_exporter-0.12.1.linux-amd64.tar.gz
tar zxvf mysqld_exporter-0.12.1.linux-amd64.tar.gz 
mv mysqld_exporter-0.12.1.linux-amd64 /usr/local/mysql_exporter

2.创建mysql配置文件、运行时可免密码连接数据库
echo '[client]
user=exporter
password=zaq1@WSX ' >/usr/local/mysql_exporter/.my.cnf 

3.设置mysql_exporter启动服务
echo '[Unit]
Description=https://prometheus.io

[Service]
Restart=on-failure
ExecStart=/usr/local/mysql_exporter/mysqld_exporter --config.my-cnf=/usr/local/mysql_exporter/.my.cnf

[Install]
WantedBy=multi-user.target' >/etc/systemd/system/mysql_exporter.service

4.启动添加后的系统服务
systemctl daemon-reload
systemctl restart mysql_exporter.service

完成mysql_exporter部署

4.检查mysql_exporter监听端口

访问页面
http://192.168.0.107:9104/metrics

得到下面结果
# HELP go_gc_duration_seconds A summary of the GC invocation durations.
# TYPE go_gc_duration_seconds summary
go_gc_duration_seconds{quantile="0"} 0
go_gc_duration_seconds{quantile="0.25"} 0
go_gc_duration_seconds{quantile="0.5"} 0
go_gc_duration_seconds{quantile="0.75"} 0
go_gc_duration_seconds{quantile="1"} 0
go_gc_duration_seconds_sum 0
go_gc_duration_seconds_count 0

5.Prometheus监控MYSQL

Prometheus配置文件/etc/prometheus/prometheus.yml，添加如下内容:
scrape_configs:
  - job_name: 'mysql'
    # 静态添加node
    static_configs:
    # 指定监控端
    - targets: ['localhost:9104']

重启Prometheus
systemctl restart prometheus

6.检查Prometheus target

判断Prometheus是否获取mysql_exporter数据。

访问这个地址
http://192.168.0.107:9090/targets ,看到红框部分，说明Prometheus监控成功

7.Grafana导入mysql模板

还是一样
https://grafana.com/grafana/dashboards 里面找到一个模板

我这里用这个 7362

至此，mysql监控已经完成。