Deploy MySQL and mysqld_exporter with Docker Compose and Configure Prometheus Monitoring

This article provides a step‑by‑step tutorial for deploying MySQL and the Prometheus MySQL exporter (mysqld_exporter) using Docker Compose, and then configuring Prometheus to monitor the database.

1. Deploy MySQL with Docker Compose

Create a directory for MySQL data and a docker-compose.yaml file containing the following service definition:

version: '3.1'
services:
  db:
    image: mysql
    restart: always
    container_name: mysql
    environment:
      TZ: Asia/Shanghai
      LANG: en_US.UTF-8
      MYSQL_ROOT_PASSWORD: 123456
      command:
        - --default-authentication-plugin=mysql_native_password
        - --character-set-server=utf8mb4
        - --collation-server=utf8mb4_general_ci
        - --lower_case_table_names=1
        - --performance_schema=1
        - --sql-mode=""
        - --skip-log-bin
    volumes:
      - /data/mysql/conf:/etc/mysql/conf.d
      - /data/mysql/data:/var/lib/mysql
    ports:
      - 3306:3306

Run the container with docker-compose up -d .

2. Deploy mysqld_exporter with Docker Compose

Create a separate directory and a docker-compose.yaml file for the exporter:

version: '3.3'
services:
  mysqld-exporter:
    image: prom/mysqld-exporter
    container_name: mysqld-exporter
    restart: always
    command:
      - '--collect.info_schema.processlist'
      - '--collect.info_schema.innodb_metrics'
      - '--collect.info_schema.tablestats'
      - '--collect.info_schema.tables'
      - '--collect.info_schema.userstats'
      - '--collect.engine_innodb_status'
    environment:
      - DATA_SOURCE_NAME=exporter:password@(192.168.18.69:3306)/
    ports:
      - 9104:9104

Start the exporter with docker-compose up -d .

3. Configure Prometheus to scrape the exporter

Add a new job to prometheus.yml :

- job_name: 'mysqld_exporter'
  static_configs:
    - targets: ['192.168.18.69:9104']
  labels:
    instance: mysql服务器

Reload the configuration using curl -X POST http://localhost:9090/-/reload (or docker exec -it prometheus promtool check config /etc/prometheus/prometheus.yml to verify).

4. Add alert rules for MySQL

Create mysqld.yml with the following rule groups:

groups:
  - name: MySQL
    rules:
      - alert: MysqlDown
        expr: mysql_up == 0
        for: 30s
        labels:
          severity: critical
        annotations:
          summary: "MySQL Down, 实例:{{ $labels.instance }}"
          description: "MySQL_exporter 连不上 MySQL，当前状态为：{{ $value }}"
      - alert: MysqlSlowQueries
        expr: increase(mysql_global_status_slow_queries[2m]) > 0
        for: 2m
        labels:
          severity: warning
        annotations:
          summary: "Mysql慢日志告警, 实例:{{ $labels.instance }}"
          description: "MySQL 在过去 2 分钟有新的 {{ $value }} 条慢查询"

After adding the rules, reload Prometheus as described above.

Following these steps results in a fully monitored MySQL instance with automatic alerts for downtime and performance issues.