SRE Principles
Site Reliability Engineering (SRE) applies software engineering to operations problems. SREs define reliability targets (SLOs), manage error budgets, and use toil automation to scale operations without proportionally scaling headcount.
40 min•By Priygop Team•Last updated: Feb 2026
SRE Core Concepts
- Toil — Manual, repetitive, automatable operational work. SREs aim to keep toil below 50% of work. Reduce via automation
- Error budget — (1 - SLO) × period = allowed downtime. 99.9% SLO = 8.7 hours/year. Budget enables risk vs reliability tradeoff
- Incident management — Severity levels (P1-P4). On-call rotations. Blameless post-mortems with action items. PagerDuty, OpsGenie
- Runbooks — Step-by-step guides for on-call responders. What to check, what to do. Reduce MTTR (Mean Time to Recovery)
- Capacity planning — Forecast resource needs based on growth. Load testing before peak events (Black Friday)
- Chaos engineering — Intentional fault injection: kill pod, introduce latency, block network. Netflix Chaos Monkey, Chaos Mesh
- SLO burn rate alerts — Alert when error budget burns 14x faster than normal (predicts exhaustion in 1 hour)