Reliability & SRE Skill

Triggers

• sre
• reliability
• slo
• sli
• error budget
• chaos engineering
• postmortem
• incident
• oncall

Purpose

To treat operations as a software problem and balance improved reliability with feature velocity.

Capabilities

1. Service Level Objectives (SLO)

• SLI: What you measure (e.g., Latency < 100ms).
• SLO: The target (e.g., 99.9% of requests meet SLI).
• Structure: 28-day rolling window. 99.9% = 43m downtime.

2. Error Budgets

• Definition: 1 - SLO. The allowed unreliability.
• Policy: If budget is exhausted -> Freeze feature launches -> Focus on stability.

3. Incident Management

• Postmortems: Blameless analysis of process failure, not human error.
• Severity Levels: SEV1 (Critical/Down) to SEV4 (Minor bug).
• MTTR: Mean Time To Recovery (Focus on fixing fast, not just preventing failure).

Instructions

1. Define Golden Signals: Latency, Traffic, Errors, Saturation.
2. Chaos Engineering: Test failure modes before they happen in production.
3. Alerting: Alert on symptoms (User Pain), not causes (CPU High).

Deliverables

• slo-definition.md: Document metrics and targets.
• runbook.md: Step-by-step recovery guide for on-call.
• postmortem.md: Incident analysis.