maxoperf concepts
Real-User Monitoring (RUM)
RUM — passive measurement of real browser sessions via a small JS beacon that reports page-views, Core Web Vitals, JS errors, and slow XHR calls.
Also known as: real user monitoring, browser RUM
Definition
Real-User Monitoring captures performance and error data from actual user sessions in the browser via a small beacon script. Each event arrives at an ingest endpoint and is rolled up into per-app dashboards (Web Vitals p75, JS error top-list, slow XHR routes, geographic split).
In Maxoperf
Maxoperf product planning treats RUM as a complement to synthetic checks and load tests. When RUM is part of a workflow, use it to explain the human experience after a release, not to prove that a system can absorb a traffic spike.
Common pitfalls
- Sampling at 100 % for a high-traffic site — pick a sample rate that fits your check budget; raise it during incidents.
- Forgetting to redact URL query strings that carry tokens — the beacon library accepts a redaction callback for that reason.
FAQ
How does RUM differ from a synthetic monitor?
A synthetic monitor fires a scripted request from a controlled probe; RUM measures whatever the real user just did, from whatever device, network, and country they are on. Both are useful — different signals.
Does RUM replace synthetic monitoring?
No. RUM explains what real users experienced; synthetic monitoring checks important paths even when no users are active.