Frontend Observability (RUM)
Monitor web, mobile, and hybrid frontends using Real User Monitoring with DQL. Targets the new RUM experience only — do not use classic RUM data.
Data Model
Three data sources, each for a different question:
| Source | Use for | Granularity |
|---|---|---|
timeseries dt.frontend.* | Trends, dashboards, alerting | Aggregated metric |
fetch user.events | Root cause, individual page views / requests / clicks / errors | Per-event |
fetch user.sessions | Bounce rate, session duration, session-level aggregates | Per-session |
Rule of thumb: start with metrics for the shape of the problem, drill into events for the why. Use sessions when the question is about user journeys, not individual interactions.
Full event model: https://docs.dynatrace.com/docs/semantic-dictionary/model/rum/user-events
Common Filters
frontend.name— frontend identifier (e.g.my-frontend)dt.rum.user_type—real_user,synthetic,robotdt.rum.application.type—webormobiledevice.type,browser.name,os.name,geo.country.iso_code
Workflows
Each workflow maps to one or more references. Load the reference when you start the workflow, not upfront.
| Workflow | Reference |
|---|---|
| Core Web Vitals (LCP, INP, CLS) | references/web-vitals.md |
| Session, bounce, engagement analysis | references/user-sessions.md |
| User actions — interaction lifecycle, completion reasons, timeouts | references/user-actions.md |
| Errors, exceptions, trace correlation | references/error-tracking.md |
| CSP violations — security policy enforcement and blocked resources | references/csp-violations.md |
| Mobile app starts, crashes, ANR, native signals | references/mobile-monitoring.md |
| Request latency, long tasks, JS profiling, geo performance | references/web-performance-analysis.md |
| Visibility changes — tab switching, background time, engagement quality | references/visibility-changes.md |
| Slow page load — backend vs render vs network vs JS triage | references/slow-page-load-playbook.md |
| Diagnosing zero results, anomalies, ambiguous data | references/troubleshooting.md |
Performance Thresholds (quick reference)
- LCP: Good < 2.5 s | Poor > 4.0 s
- INP: Good < 200 ms | Poor > 500 ms
- CLS: Good < 0.1 | Poor > 0.25
- Mobile cold start: Good < 3 s | Poor > 5 s
- Long tasks: > 50 ms problematic, > 250 ms severe
When to Use
Use this skill for real-user web, mobile, or hybrid frontend telemetry — Core Web Vitals, sessions, clicks, errors, crashes, request latency from the browser/app, and frontend↔backend trace correlation.
Use a different skill for:
- Synthetic monitors / availability checks →
dt-obs-synthetic - Backend services, traces, spans →
dt-obs-services,dt-obs-tracing - Infrastructure, hosts →
dt-obs-hosts - Logs →
dt-obs-logs - Problems and incidents →
dt-obs-problems
