MySQL

Collect query throughput, connection pool, InnoDB buffer pool, replication status, and slow query metrics from MySQL using mysqld_exporter.

Pattern: mysqld_exporter → Prometheus scrape → xScaler remote_write

---

Dashboard

---

Prerequisites

• MySQL 5.7 or later (or MariaDB 10.3+)
• A dedicated monitoring user
• Prometheus or Grafana Alloy
• xScaler tenant credentials

---

Step 1 — Create a monitoring user

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

---

Step 2 — Run mysqld_exporter

docker run --rm -d \
  --name mysql-exporter \
  --network host \
  -e DATA_SOURCE_NAME="xscaler_monitor:strongpassword@(localhost:3306)/" \
  prom/mysqld-exporter \
  --collect.global_status \
  --collect.global_variables \
  --collect.info_schema.innodb_metrics \
  --collect.info_schema.processlist \
  --collect.slave_status

Verify:

curl -s http://localhost:9104/metrics | grep mysql_up
# mysql_up 1

---

Step 3 — Scrape and forward to xScaler

Prometheus

scrape_configs:
  - job_name: mysql
    static_configs:
      - targets: ['localhost:9104']
        labels:
          instance: primary

remote_write:
  - url: https://euw1-01.m.xscalerlabs.com/api/v1/push
    authorization:
      credentials: <token>
    headers:
      X-Scope-OrgID: <tenant-id>

Grafana Alloy

prometheus.scrape "mysql" {
  targets    = [{"__address__" = "localhost:9104"}]
  forward_to = [prometheus.remote_write.xscaler.receiver]
}

prometheus.remote_write "xscaler" {
  endpoint {
    url = "https://euw1-01.m.xscalerlabs.com/api/v1/push"
    authorization {
      type        = "Bearer"
      credentials = "<token>"
    }
    headers = { "X-Scope-OrgID" = "<tenant-id>" }
  }
}

---

OpenTelemetry Collector

receivers:
  mysql:
    endpoint: localhost:3306
    username: xscaler_monitor
    password: strongpassword
    collection_interval: 15s

processors:
  memory_limiter:
    check_interval: 1s
    limit_mib: 256
  batch:
    timeout: 10s

exporters:
  otlphttp/xscaler:
    endpoint: https://euw1-01.m.xscalerlabs.com
    headers:
      Authorization: "Bearer <token>"
      X-Scope-OrgID: "<tenant-id>"

service:
  pipelines:
    metrics:
      receivers:  [mysql]
      processors: [memory_limiter, batch]
      exporters:  [otlphttp/xscaler]

---

Logs

Collect error log, slow query log, and general query log. Add the following to your Alloy config:

local.file_match "mysql_logs" {
  path_targets = [{
    __address__ = "localhost",
    __path__    = "/var/log/mysql/*.log",
    instance    = constants.hostname,
    job         = "integrations/mysql",
  }]
}

loki.source.file "mysql_logs" {
  targets    = local.file_match.mysql_logs.targets
  forward_to = [loki.write.xscaler.receiver]
}

loki.write "xscaler" {
  endpoint {
    url = "https://euw1-01.l.xscalerlabs.com/api/v1/logs/push"

    http_client_config {
      authorization {
        type        = "Bearer"
        credentials = env("XSCALER_TOKEN")
      }
    }

    headers = { "X-Scope-OrgID" = env("XSCALER_TENANT_ID") }
  }
}

Key metrics

Metric	Description
mysql_up	Exporter reachability (1 = up)
mysql_global_status_threads_connected	Current open connections
mysql_global_variables_max_connections	Max allowed connections
mysql_global_status_queries	Total queries executed
mysql_global_status_slow_queries	Queries exceeding long_query_time
mysql_global_status_innodb_buffer_pool_reads	InnoDB disk reads (cache misses)
mysql_global_status_innodb_buffer_pool_read_requests	InnoDB buffer pool requests
mysql_global_status_bytes_received	Bytes received from clients
mysql_global_status_bytes_sent	Bytes sent to clients
mysql_slave_status_seconds_behind_master	Replication lag (seconds)

---

Useful PromQL queries

# Connection usage %
mysql_global_status_threads_connected
/ mysql_global_variables_max_connections * 100

# Query rate/sec
rate(mysql_global_status_queries[5m])

# InnoDB buffer pool hit ratio (should be > 99%)
(1 - rate(mysql_global_status_innodb_buffer_pool_reads[5m])
   / rate(mysql_global_status_innodb_buffer_pool_read_requests[5m])) * 100

# Slow queries rate
rate(mysql_global_status_slow_queries[5m])

# Replication lag
mysql_slave_status_seconds_behind_master