查看“Prometheus 监控插件mysqld exporter”的源代码

== 要增加授权 ==
 mysql> GRANT PROCESS, REPLICATION CLIENT, SELECT ON *.* TO 'exporter'@'localhost' IDENTIFIED BY 'exporter123' WITH MAX_USER_CONNECTIONS 3;
 mysql> flush privileges;
== 安装mysqld_exporter ==
 wget https://github.com/prometheus/mysqld_exporter/releases/download/v0.12.1/mysqld_exporter-0.12.1.linux-amd64.tar.gz
 tar xzvf  mysqld_exporter-0.12.1.linux-amd64.tar.gz
 mv mysqld_exporter-0.12.1.linux-amd64.tar.gz  mysqld_exporter
 chown -R root:root /usr/local/prometheus/mysqld_exporter/mysqld_exporter
 chmod 755 /usr/local/prometheus/mysqld_exporter/mysqld_exporter

== 修改启动参数 ==
启动参数参考 https://github.com/prometheus/mysqld_exporter

 vim /usr/lib/systemd/system/mysqld_exporter.service
 [Unit]
 Description=mysqld_exporter
 After=network.target
 [Service]
 Type=simple
 User=mysql
 Environment=DATA_SOURCE_NAME=exporter:exporter123@(localhost:3306)/
 ExecStart=/usr/local/prometheus/mysqld_exporter/mysqld_exporter --web.listen-address=0.0.0.0:9104 
   --config.my-cnf /etc/my.cnf \
   --collect.slave_status \
   --collect.slave_hosts \
   --log.level=error \
   --collect.info_schema.processlist \
   --collect.info_schema.innodb_metrics \
   --collect.info_schema.innodb_tablespaces \
   --collect.info_schema.innodb_cmp \
   --collect.info_schema.innodb_cmpmem 
 Restart=on-failure
 [Install]
 WantedBy=multi-user.targe

 [Unit]
 Description=mysqld_exporter
 
 [Service]
 Type=simple
 Restart=on-failure
 ExecStart=/usr/local/mysqld_exporter/mysqld_exporter --config.my-cnf=/usr/local/mysqld_exporter/my.cnf 
 
 [Install]
 WantedBy=multi-user.target

== 启动exporter ==

 chown -R root:root /usr/lib/systemd/system/mysqld_exporter.service
 chmod 644 /usr/lib/systemd/system/mysqld_exporter.service
 systemctl daemon-reload
 systemctl enable mysqld_exporter.service
 systemctl start mysqld_exporter.service


访问localhost:9104/metrics可以看到mysql的指标


== 修改prometheus配置文件 ==
scrape_configs下面添加

 vim /usr/local/prometheus/prometheus.yml
 scrape_configs:
   - job_name: 'mysql'
     static_configs:
       - targets: ['localhost:9104']

== 设置报警规则 ==
可参考示例：https://github.com/prometheus/mysqld_exporter/blob/master/example.rules

 groups:
 - name: GaleraAlerts
   rules:
   - alert: MySQLReplicationNotRunning
     expr: mysql_slave_status_slave_io_running == 0 or mysql_slave_status_slave_sql_running
       == 0
     for: 2m
     labels:
       severity: critical
     annotations:
       description: Slave replication (IO or SQL) has been down for more than 2 minutes.
       summary: Slave replication is not running