Monitoring

Introduction Observability is the ability to understand the internal state of a system based on its external outputs. Unlike traditional monitoring, which tells you what is broken, observability helps you understand why it’s broken, even for issues you’ve never encountered before. Core Principle: “You can’t fix what you can’t see. You can’t see what you don’t measure.” The Three Pillars Overview ┌─────────────────────────────────────────┐ │ OBSERVABILITY │ ├─────────────┬──────────────┬────────────┤ │ METRICS │ LOGS │ TRACES │ ├─────────────┼──────────────┼────────────┤ │ What/When │ Why/Details │ Where │ │ Aggregated │ Individual │ Causal │ │ Time-series │ Events │ Flows │ │ Dashboards │ Search │ Waterfall │ └─────────────┴──────────────┴────────────┘ When to Use Each: …

Introduction Prometheus queries can become slow and resource-intensive as your metrics scale. This guide covers PromQL optimization techniques, recording rules, and performance best practices to keep your monitoring fast and efficient. PromQL Optimization Understanding Query Performance Factors affecting query performance: Number of time series matched Time range queried Query complexity Cardinality of labels Rate of data ingestion Check query stats: # Grafana: Enable query inspector # Shows: Query time, series count, samples processed 1. Limit Time Series Selection Bad (matches too many series): …

Introduction Service Level Indicators (SLIs), Service Level Objectives (SLOs), and Service Level Agreements (SLAs) are fundamental concepts in Site Reliability Engineering. Understanding and implementing them correctly is crucial for maintaining reliable services. Core Concepts SLI (Service Level Indicator) Definition: A quantitative measure of service reliability from the user’s perspective. Common SLIs: Availability: Percentage of successful requests Latency: Proportion of requests served faster than threshold Throughput: Requests processed per second Error Rate: Percentage of failed requests Example SLI Definitions: …