LF Observability study guide
LF Observability · Work through your exam, one topic at a time.
The Linux Foundation Certified Observability Specialist (LFCOS) is positioned as a Linux Foundation certification aimed at engineers who build and operate observable systems. Before you plan study time or budget, note an important limitation: the only permitted source for this page, the Linux Foundation training site's LFCOS certification URL, returned a "Page Not Found" error when retrieved. That page contains no exam objectives, no domain weights, no question count, no duration, no passing score, no fee, and no retake or validity policy. Everything numeric or policy-related is therefore unconfirmed here rather than guessed. Topics on this exam: Observability Fundamentals, Metrics, Logs, and Traces, OpenTelemetry Instrumentation and Collection, and Observability Platforms and Operations. The LF Observability study guide has 4 sections and about 1,443 words.
01Observability Fundamentals
Observability Fundamentals checks whether you can separate monitoring from observability and apply SLIs, SLOs, error budgets, and telemetry economics. Monitoring answers known questions; observability lets you ask new questions from high-dimensional telemetry.
375 words, about 2 min02Metrics, Logs, and Traces
Metrics, Logs, and Traces tests data-model fluency: instrument types, aggregation, correlation, sampling, and storage trade-offs across the three pillars. Prometheus metric types: counter is monotonic; gauge is arbitrary; histogram exposes buckets plus sum and count; summary exposes client-side quantiles.
380 words, about 2 min03OpenTelemetry Instrumentation and Collection
OpenTelemetry Instrumentation and Collection tests the API/SDK split, auto- and manual instrumentation, resources and semantic conventions, context propagation, and Collector pipeline design. The OpenTelemetry API is stable and safe to call without an SDK; it becomes a no-op.
349 words, about 2 min04Observability Platforms and Operations
Observability Platforms and Operations tests backend selection, querying, retention, dashboards, alerting, SLO operations, cost control, security, and Kubernetes deployment patterns. Prometheus uses pull-based scraping, service discovery, and local TSDB; remote write feeds long-term stores such as Thanos or Mimir.
339 words, about 2 min