SRE Cheat Sheet 2026

The 30 highest-yield SRE facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. Which deployment strategy sends a small percentage of production traffic to a new version while the rest uses the old version? → Canary deployment
2. A team uses Elasticsearch, Logstash, and Kibana (ELK stack). What is Logstash's role? → Ingesting, transforming, and shipping log data to Elasticsearch
3. What is 'traffic shaping' used for in capacity management? → Controlling the rate and distribution of incoming requests to protect backend capacity
4. Why is post-incident review important? → To analyze the root cause and prevent recurrence
5. In Kubernetes, what does a Helm chart provide? → A package of pre-configured Kubernetes resources
6. A runbook step says 'restart the service if latency exceeds 2 seconds.' This is an example of what type of runbook content? → Remediation step
7. What is the purpose of a 'blameless post-mortem' in on-call culture? → To analyze what went wrong and improve systems without attributing personal fault
8. Which of the following is an example of toil that is ALSO a reliability risk if left unaddressed? → Manually rotating API keys before they expire
9. Why are postmortems important after incidents? → To learn from incidents and improve systems
10. Which practice involves deliberately taking down entire availability zones in production to test failover? → Region evacuation drills
11. What is the purpose of a 'capacity model' in SRE practice? → Mapping resource consumption to traffic levels to forecast infrastructure needs
12. In the context of SRE and IaC, what is a 'golden image'? → A pre-built, pre-configured machine image used as a base for new instances
13. Which formula correctly expresses the error budget for a 99.9% monthly SLO? → 0.1% of total minutes in the month ≈ 43.8 minutes of allowed downtime
14. What is the primary purpose of using Infrastructure as Code (IaC)? → To automate infrastructure setup and ensure consistent environments
15. What is the purpose of an incident response playbook? → To define and document standard response steps
16. What does SLI stand for in SRE terminology? → Service Level Indicator
17. In the context of capacity planning, what is 'demand forecasting'? → Predicting future resource needs based on business and traffic growth trends
18. Which metric best indicates that a system has recovered from a chaos experiment? → All steady state indicators returning to pre-experiment values
19. What is the primary purpose of a log aggregation pipeline in an SRE context? → To centralize logs from multiple sources for unified search and analysis
20. How does Terraform support IaC practices? → By allowing declarative infrastructure provisioning as code
21. Which tool is commonly used for configuration management in SRE practices? → Ansible
22. Which practice helps reduce risk during changes? → Canary deployments and feature flags
23. Which of the following best describes Infrastructure as Code? → Infrastructure managed using scripts and configuration files
24. What is 'latency injection' used to test in a microservices architecture? → How upstream callers handle slow dependencies, including timeout and retry behavior
25. Which of the following best describes a key competency required for observability & logging in SRE practice? → Strong analytical skills combined with effective communication and ethical judgment
26. Which practice ensures that a failed pipeline step stops downstream stages from running? → Fast-fail (fail-fast) configuration where any failing step aborts the pipeline
27. Which load testing approach best simulates realistic production traffic for capacity planning? → Replay of recorded production traffic traces
28. What does 'headroom' refer to in capacity planning? → Reserved capacity above current usage to absorb unexpected demand
29. What does 'fault injection' mean in the context of resilience testing? → Deliberately introducing errors, latency, or resource exhaustion into a running system
30. When should chaos experiments first be run in a CI/CD pipeline? → In staging or pre-production environments before changes reach production