Quick answer
A practical guide to MySQL TCP monitoring, what port 3306 can tell you, and why database monitoring should complement website uptime checks.
Why MySQL needs its own monitor
When MySQL is unavailable, your application may still serve static pages or cached content. An HTTP monitor can therefore stay green while login, search, or checkout requests fail.
Monitor the service boundary
MySQL commonly uses TCP port 3306. A port monitor can verify that the database host accepts connections. This is intentionally simpler than executing credentials or queries against a production database.
Use the right level of monitoring
TCP checks answer: “Can I establish a connection?” Application checks answer: “Does my application still work?” Both can be useful, and combining them makes incident diagnosis faster.
How to interpret a failed TCP check
A refused connection, timeout, firewall change, host failure, or stopped database service can all produce an alert. Use the exact timestamp to correlate the event with operating-system and database logs.
PingStag
PingStag's TCP monitor uses a direct socket connection with a timeout and records the connection latency, making it suitable for database and infrastructure availability checks.
Sources and references
Related PingStag guides
Stop Pinging Your Frontend: Monitoring Databases at Layer 4
Why HTTP monitoring is blind to internal infrastructure failures, and how raw TCP sockets fix the gap.
How to Monitor PostgreSQL Availability on Port 5432
Learn how TCP port monitoring can detect PostgreSQL availability problems even when your website still appears to be working.
Cloudflare 403s vs Real Downtime: Decoding WAF Blocks
Your monitoring bot got blocked by a firewall, but the site is fine. How Layer-7 heuristics stop fake alerts.
How to Monitor Redis on Port 6379
Learn why Redis availability matters, how TCP port 6379 monitoring works, and where a cache availability check fits in a production monitoring strategy.
