The RED and USE Methods
Learn two classic monitoring methodologies, RED for request-driven services and USE for resources, and when to apply each to focus your dashboards.
The RED and USE Methods is a free System Observability: Logging, Metrics & Tracing (ELK + OpenTelemetry) lesson on CoddyKit — lesson 4 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the System Observability: Logging, Metrics & Tracing (ELK + OpenTelemetry) learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Why Methodologies?
With endless metrics available, teams drown in dashboards. RED and USE are proven recipes that tell you which few signals actually matter.
The RED Method
RED targets request-driven services and tracks three signals: Rate, Errors, and Duration.
- Rate: requests per second
- Errors: failed requests per second
- Duration: latency distribution
RED in Practice
For every service, chart these three. Together they answer how busy it is, whether it is failing, and whether it is slow.
rate(http_requests_total[5m])
rate(http_requests_total{status=~"5.."}[5m])
histogram_quantile(0.95, http_request_duration_seconds_bucket)Why RED Works
RED reflects what users feel: are their requests served, served correctly, and served quickly. It maps directly to user experience.
The USE Method
USE targets resources and tracks Utilization, Saturation, and Errors for each component like CPU, memory, disk, and network.
USE Defined
For each resource:
- Utilization: percent of time busy
- Saturation: queued work waiting
- Errors: error events
USE in Practice
Walk the resource list and apply USE to each, finding bottlenecks systematically rather than guessing.
CPU: utilization %, run-queue length, throttles
Disk: busy %, IO wait queue, IO errorsSaturation Is the Key
High utilization can be fine; saturation, the backlog of waiting work, is the early warning that a resource is becoming a bottleneck.
RED vs USE
They are complementary.
- RED: service health from the user view
- USE: resource health from the system view
RED tells you something is wrong; USE often tells you why.
Combining Both
A latency spike (RED Duration) might trace to disk saturation (USE). Using both methods links symptom to cause.
Building Focused Dashboards
Design service dashboards around RED and host dashboards around USE. This keeps panels meaningful instead of a wall of noise.
Quick Check
Match method to target.
Recap
You learned two focusing methodologies: RED (Rate, Errors, Duration) for request-driven services from the user perspective, and USE (Utilization, Saturation, Errors) for resources from the system perspective. RED reveals symptoms, USE reveals causes, and together they keep dashboards meaningful.
Frequently asked questions
Is the “The RED and USE Methods” lesson free?
Yes — the full text of “The RED and USE Methods” is free to read here on the web, and the System Observability: Logging, Metrics & Tracing (ELK + OpenTelemetry) course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the System Observability: Logging, Metrics & Tracing (ELK + OpenTelemetry) course, upgrade to CoddyKit PRO.
What will I learn in “The RED and USE Methods”?
Learn two classic monitoring methodologies, RED for request-driven services and USE for resources, and when to apply each to focus your dashboards. You practise System Observability: Logging, Metrics & Tracing (ELK + OpenTelemetry) with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start System Observability: Logging, Metrics & Tracing (ELK + OpenTelemetry)?
No prior experience is required. System Observability: Logging, Metrics & Tracing (ELK + OpenTelemetry) on CoddyKit is structured for beginners through advanced learners; this is — lesson 4 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “The RED and USE Methods” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this System Observability: Logging, Metrics & Tracing (ELK + OpenTelemetry) lesson?
Yes. Every System Observability: Logging, Metrics & Tracing (ELK + OpenTelemetry) lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- Correlating Logs, Metrics, Traces
- Anomaly Detection and AI Ops
- SLOs, SLIs, and Error Budgets
- The RED and USE Methods