MySQL/MariaDB Health Monitoring with Python: Connections, Slow Queries, Replication (Free Tool)

Why MySQL Health Monitoring Matters

MySQL and MariaDB power the majority of web applications. Without proper monitoring, you will not notice connection pool exhaustion, slow query accumulation, or replication lag until your application starts timing out.

dargslan-mysql-health is a free Python CLI tool that gives you instant visibility into your MySQL/MariaDB server health — connection usage, slow queries, replication status, and database sizes — all without external dependencies.

Install dargslan-mysql-health

pip install dargslan-mysql-health

Requires the mysql CLI client to be installed on your system (included in mysql-client or mariadb-client packages).

Quick Health Report

dargslan-mysql report

Displays server version, uptime, connection statistics, slow query info, and any detected issues.

Health Checks

Connection Monitoring

dargslan-mysql connections

Shows current connections, max connections, max used connections, and usage percentage. Alerts when usage exceeds 80% (warning) or 95% (critical).

Slow Query Analysis

dargslan-mysql slow

Checks if the slow query log is enabled, the long_query_time threshold, and total slow query count. Alerts when slow queries exceed 1000.

Database Sizes

dargslan-mysql databases

Lists all databases with their size in MB, sorted by size descending. Useful for identifying which databases are consuming the most disk space.

Replication Status

dargslan-mysql replication

Checks if replication is configured, IO/SQL thread status, seconds behind master, and last error. Critical alerts for broken replication.

Custom Connection

# Connect to remote server
dargslan-mysql report -H 10.0.0.5 -P 3306 -u admin -p secretpass

# Or use environment variables
export MYSQL_USER=admin
export MYSQL_PASSWORD=secretpass
dargslan-mysql report

Python API

from dargslan_mysql_health import MySQLHealth

mh = MySQLHealth(host="localhost", user="root")

# Full audit
issues = mh.audit()
for issue in issues:
    print(f"[{issue['severity'].upper()}] {issue['message']}")

# Connection status
conn = mh.connection_status()
print(f"Connections: {conn['current_connections']}/{conn['max_connections']} ({conn['usage_percent']}%)")

# Database sizes
for db in mh.database_sizes():
    print(f"{db['database']}: {db['size_mb']} MB")

# Server info
info = mh.server_info()
print(f"MySQL {info['version']}, uptime: {info['uptime_human']}")

# Replication
repl = mh.replication_status()
if repl['configured']:
    print(f"IO: {repl['io_running']}, SQL: {repl['sql_running']}")
    print(f"Lag: {repl['seconds_behind']}s")

Severity Levels

Monitoring Automation

# Add to crontab for hourly checks
0 * * * * dargslan-mysql issues >> /var/log/mysql-health.log 2>&1

# Or use in Python monitoring script
import json
mh = MySQLHealth()
issues = mh.audit()
if any(i["severity"] == "critical" for i in issues):
    # Send alert (email, Slack, PagerDuty, etc.)
    send_alert("MySQL CRITICAL", json.dumps(issues))

Download the Free Cheat Sheet

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