Not just “how to use it” but explaining “why it was designed this way”.

Learning Path#

Foundational Concepts#

If you’re new to Observability, follow this order.

1. Three Pillars of Observability - Roles of Metrics, Logs, Traces and their interconnections
2. Metrics Fundamentals - Understanding Counter, Gauge, Histogram, Summary types
3. Prometheus Architecture - Pull model, time series DB, service discovery

PromQL Deep Dive#

A deep exploration of the Prometheus query language.

4. PromQL Overview - PromQL learning roadmap
5. Syntax Basics - Selectors, label matching, time ranges
6. Aggregation Operators - sum, avg, count, topk, by/without
7. rate and increase - Core of Counter metric processing
8. histogram_quantile - Calculating percentiles (P50/P95/P99)
9. Recording Rules - Pre-computing complex queries
10. Alerting Rules - Writing alerting rules

SRE Golden Signals#

Applying the 4 core indicators proposed by Google SRE by service type.

11. Golden Signals Overview - Introduction to 4 signals and USE/RED methods
12. Latency - Latency measurement strategies
13. Traffic - Traffic/throughput monitoring
14. Errors - Error rate definition and classification
15. Saturation - Saturation (resource utilization)
16. Application by Service Type - Guide for Web API, Kafka, DB

Logging and Tracing#

Integrating logs and distributed tracing beyond metrics.

17. Log Aggregation - Loki vs ELK comparison, log design patterns
18. Distributed Tracing - Span, Trace ID, Context Propagation
19. OpenTelemetry - Observability standards and integration methods

Operations#

Practical knowledge for effective operations.

20. Dashboard Design - Effective visualization principles

Document Structure Pattern#

Each concept document follows this structure:

1. TL;DR - Key summary (within 5 lines)
2. Why is it needed? - Problem situation and solution
3. Core Concepts - Detailed explanation + diagrams
4. Practical Examples - Code ready to apply
5. Trade-offs - Pros/cons and selection criteria
6. Next Steps - Related document links

Recommended Learning Path#

graph TD
    subgraph "Beginner (1-2 hours)"
        A["Three Pillars"] --> B["Metrics Fundamentals"]
        B --> C["Prometheus Architecture"]
    end

    subgraph "PromQL Deep Dive (2-3 hours)"
        D["Syntax Basics"] --> E["Aggregation Operators"]
        E --> F["rate/increase"]
        F --> G["histogram_quantile"]
        G --> H["Recording Rules"]
        H --> I["Alerting Rules"]
    end

    subgraph "SRE Perspective (1-2 hours)"
        J["Golden Signals Overview"] --> K["4 Signals Deep Dive"]
        K --> L["Application by Service Type"]
    end

    C --> D
    C --> J
    I --> L