Quick answer: what synthetic monitoring is
Synthetic monitoring runs scheduled, controlled checks from defined locations to test endpoints, pages or scripted user journeys. Because the inputs are repeatable, synthetics are useful for availability detection, regression checks and reproducing known workflows.
Why synthetic monitoring matters
Real-user traffic can be sparse, seasonal or absent during an outage. Synthetic probes continue testing on a fixed schedule and can alert before a user reports the problem.
What to measure
- check success and failure by location
- DNS, connection, TLS and server timing
- HTTP status and response assertions
- scripted journey step duration and failure point
- probe health and false-positive rate
How to implement it without creating noise
- Start with a simple external availability check for the most important endpoint.
- Add content or transaction assertions so a fast error page is not counted as healthy.
- Use multiple independent locations for critical public services.
- Create scripted journeys only for stable, high-value workflows and maintain them like test code.
Common mistakes
- Relying on one probe location for a global service.
- Alerting on transient network noise without confirmation.
- Writing brittle scripts that break whenever the UI changes.
How it fits with related monitoring practices
Synthetic monitoring uses controlled test traffic; RUM observes real visitors. Synthetics are excellent for repeatability and coverage when no user is present, while RUM reveals real-world diversity.
Frequently asked questions
What should I start with?
Start with one critical endpoint or user journey and an assertion that represents success, then choose probe locations and frequency based on the failure you need to detect.
Should I alert on every metric?
Alert on confirmed synthetic failures or sustained performance regressions that require action. Use retry/confirmation logic where transient network noise would otherwise create false pages.
How do I know the setup is working?
Break one assertion safely and verify the correct probe, step, response detail and notification reach the owner; then restore it and confirm recovery is recorded cleanly.
Sources and further reading for synthetic monitoring
Use primary sources for definitions and current product capabilities. The references below were reviewed for this content update.