Quick answer
Learn how TCP port monitoring can detect PostgreSQL availability problems even when your website still appears to be working.
Why monitor PostgreSQL separately?
Your website can return a cached page while the database behind authentication, checkout, or application queries is unavailable. Monitoring the database service at its network boundary gives you another signal.
Why port 5432 matters
PostgreSQL commonly listens on TCP port 5432. A TCP monitor can test whether a host accepts a connection on that port. This does not run a SQL query, but it can tell you whether the service is reachable and accepting connections at the network layer.
Know the limitation
A successful TCP handshake does not prove that every database query will succeed. It is a Layer 4 availability check, not a full application transaction test.
Combine layers
For a production application, pair the PostgreSQL port check with a website or API monitor. The combination lets you distinguish “the database port is unreachable” from “the database is reachable but the application is malfunctioning.”
PingStag TCP monitoring
PingStag can establish direct TCP connections to a host and port and record the connection latency, giving teams a simple way to watch infrastructure that does not expose HTTP.
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 MySQL Availability on Port 3306
A practical guide to MySQL TCP monitoring, what port 3306 can tell you, and why database monitoring should complement website uptime checks.
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.
