Grafana Alloy MySQL Monitoring

Use Grafana Alloy on MySQL servers to ship MySQL and host metrics to Grafana Cloud. Alloy is Grafana’s collector: it scrapes exporters locally and remote-writes the results.

This guide assumes you are installing Alloy on a Linux server that already runs MySQL (or MariaDB) on localhost:3306. Store generated passwords in 1Password with the rest of the server credentials.

Install Alloy

The Grafana Cloud collector wizard generates the fleet-management, Prometheus, and Loki blocks for this stack. Keep those generated values. Do not copy another server’s remotecfg id.

1. Open collector setup

   Log in to Grafana Cloud and open Connections → Collector / Collector setup.

2. Install Alloy

   Choose Alloy and follow the Linux install instructions for the target server. Run the install commands on the server itself.

   The installer writes /etc/alloy/config.alloy and sets GCLOUD_RW_API_KEY for Alloy’s systemd service. Leave that environment variable in place.

3. Confirm the service is running

   sudo systemctl status alloy.service

Create the MySQL exporter user

Alloy should not use the database root user. Create a dedicated exporter account with a tight privilege set and a connection cap.

1. Generate a password

   openssl rand -base64 48 | tr -dc 'A-Za-z0-9' | head -c 32; echo

   Store the password in 1Password before continuing. The command above produces alphanumeric characters only, so it is safe to paste into the Alloy DSN later.

2. Open a MySQL admin session

   sudo mysql

   Use whatever admin login the server already has if sudo mysql is not configured.

3. Create the user and grants

   Replace YourGeneratedPassword with the password from step 1.

   CREATE USER 'exporter'@'localhost' IDENTIFIED BY 'YourGeneratedPassword' WITH MAX_USER_CONNECTIONS 3;
   
   GRANT PROCESS, REPLICATION CLIENT ON *.* TO 'exporter'@'localhost';
   GRANT SELECT ON performance_schema.* TO 'exporter'@'localhost';
   
   FLUSH PRIVILEGES;

   MAX_USER_CONNECTIONS 3 stops the exporter from exhausting MySQL connection slots if scrapes overlap.

Configure Alloy

Edit the Alloy config and merge the MySQL and host-metrics blocks into the file the installer created.

sudo nano /etc/alloy/config.alloy

Keep the generated remotecfg, prometheus.remote_write, and loki.write blocks exactly as the wizard wrote them (URLs, usernames, and GCLOUD_RW_API_KEY). Set remotecfg id to the Forge server name, for example uk-ldn-project-01. Do not copy another server’s id.

Then append the following MySQL and system-metrics pipelines. Replace MYSQL_EXPORTER_PASSWORD with the password created above.

// ------- MySQL Export -------

prometheus.exporter.mysql "mysql" {
  data_source_name = "exporter:MYSQL_EXPORTER_PASSWORD@(localhost:3306)/"

  enable_collectors = [
    "global_status",
    "global_variables",
    "slave_status",
    "info_schema.innodb_metrics",
    "info_schema.processlist",
    "info_schema.tables",
    "perf_schema.eventsstatements",
    "perf_schema.file_instances",
    "perf_schema.memory_events",
  ]
}

discovery.relabel "mysql" {
  targets = prometheus.exporter.mysql.mysql.targets

  rule {
    target_label = "instance"
    replacement  = constants.hostname
  }
}

prometheus.scrape "mysql" {
  targets    = discovery.relabel.mysql.output
  forward_to = [prometheus.remote_write.metrics_service.receiver]
  job_name   = "mysql"
}

// ------- System Stats Export -------

discovery.relabel "integrations_node_exporter" {
  targets = prometheus.exporter.unix.integrations_node_exporter.targets

  rule {
    target_label = "instance"
    replacement  = constants.hostname
  }

  rule {
    target_label = "job"
    replacement  = "integrations/node_exporter"
  }
}

prometheus.exporter.unix "integrations_node_exporter" {
  disable_collectors = ["ipvs", "btrfs", "infiniband", "xfs", "zfs"]

  filesystem {
    fs_types_exclude     = "^(autofs|binfmt_misc|bpf|cgroup2?|configfs|debugfs|devpts|devtmpfs|tmpfs|fusectl|hugetlbfs|iso9660|mqueue|nsfs|overlay|proc|procfs|pstore|rpc_pipefs|securityfs|selinuxfs|squashfs|sysfs|tracefs)$"
    mount_points_exclude = "^/(dev|proc|run/credentials/.+|sys|var/lib/docker/.+)($|/)"
    mount_timeout        = "5s"
  }
}

prometheus.scrape "integrations_node_exporter" {
  targets    = discovery.relabel.integrations_node_exporter.output
  forward_to = [prometheus.remote_write.metrics_service.receiver]
  job_name   = "integrations/node_exporter"
}

Do not duplicate components

If the wizard already added a node exporter scrape pipeline, keep a single copy. Duplicate component labels will prevent Alloy from starting.

Restart and verify

1. Restart Alloy

   sudo systemctl restart alloy.service

2. Check the service

   sudo systemctl status alloy.service

   It should be active (running). If it failed, inspect the logs:

   sudo journalctl -u alloy.service -e

   Common causes are a syntax error in config.alloy, a duplicated component label, or a bad MySQL DSN/password.

3. Confirm metrics in Grafana

   In Grafana Cloud, open Explore against the Prometheus datasource and look for:

   • mysql_up (should be 1)
   • mysql_global_status_uptime
   • node_cpu_seconds_total (host metrics)

   Filter on the server instance label (the machine hostname) if several collectors are reporting.

What this collects

Pipeline	Source	Typical use
mysql	prometheus.exporter.mysql	Connections, InnoDB, processlist, statement stats, replication
integrations/node_exporter	prometheus.exporter.unix	CPU, memory, disk, filesystem

Host metrics complement Forge’s server resource monitors. Alloy is the source for Grafana dashboards and longer-term trends; Forge monitors remain the first-line alerting on the server itself.