# REL12: How do you test reliability?

## References

- [AWS REL12](https://docs.aws.amazon.com/wellarchitected/latest/framework/rel-12.html)
- [LitmusChaos](https://litmuschaos.io/)
- [Gremlin](https://www.gremlin.com/)

## Date

2025-11-27

## Focus Area

Failure Management

## Tổng quan

REL12 tập trung vào testing reliability through chaos engineering.

## Best Practices

### REL12-BP01: Use playbooks to investigate failures
Failure investigation playbooks.

### REL12-BP02: Perform post-incident analysis
Blameless postmortems.

### REL12-BP03: Test functional requirements
Functional testing.

### REL12-BP04: Test scaling and performance requirements
Load testing.

### REL12-BP05: Test resiliency using chaos engineering
Chaos experiments.

### REL12-BP06: Conduct game days regularly
Game day exercises.

## Chaos Engineering

1. Define steady state
2. Hypothesize
3. Introduce variables
4. Run experiment
5. Analyze results

## Checklist

- [ ] Failure playbooks exist
- [ ] Post-incident analysis process
- [ ] Load testing performed
- [ ] Chaos experiments run
- [ ] Game days scheduled
