Simple definition
Synthetic monitoring regularly simulates a request or user journey to verify that a service works before a real user reports an outage.
Technical definition
Probes run HTTP, DNS, network, or multi-step checks at scheduled intervals. They record availability, response time, and functional results, and can trigger alerts when thresholds or expected conditions fail.
How it works / role
Each probe repeats the same scenario from one or more locations. Results are compared with expected criteria, and repeated failures can open an alert. Multiple measurement locations help distinguish a global outage from a local network or DNS issue.
What is it used for?
Detect outages quickly, measure the experience of a critical workflow, and continuously validate services from external or distributed locations.
Practical example
A probe signs in to an application every five minutes, checks the HTTP response and expected content, and alerts after three consecutive failures.
Common issues
- The scenario is too simple to represent real usage
- A probe network or DNS problem creates a false positive
- Test credentials expire or the account becomes locked
- Alert thresholds are too sensitive or too permissive
Key takeaway: Effective synthetic monitoring validates a functional outcome and uses repeated or distributed measurements to reduce false positives.