Port Monitor

Port monitors verify that a TCP service is accepting connections on a specific host and port. They are ideal for services where a protocol-level HTTP check is not appropriate.

Configuration

IP or Host - A hostname or IP address without http:// or https://.
TCP Port - A port from 1 to 65535.
Request Timeout - The number of seconds to wait for the TCP connection.
Schedule and Regions - How often and where the checks run.

Incident Detection

Port monitors support consecutive failure and recovery thresholds plus immediate confirmation checks on alternate runners when possible.

Results

Port monitor checks record success or failure, errors, timing metrics, and region details. Incident pages include root cause, timing, affected regions, assertions, and traceroute details when available.

Use Cases

Database listener checks such as PostgreSQL on 5432 or MySQL on 3306.
SSH, SMTP, LDAP, Redis, Kafka, or custom TCP services.
Private service reachability from self-hosted runners.
Firewall or load balancer validation.

Limitations

A successful connection proves the port is open, not that the service completes application-level work.
For HTTP services, use an HTTP monitor so status codes, body validation, SSL, and domain checks are available.

Examples

Host: db.example.com
Port: 5432
Timeout: 30 seconds
Schedule: Every 5 minutes
Regions: Self-hosted us-east-1