What is GameDay in Chaos Engineering?

Question

Accepted Answer

**GameDay** — planned experiment with intentional failures to test resilience.

**Process:**
1. **Planning:** goals, scenarios, success criteria, rollback plan.
2. **Execution:** Chaos Mesh/Litmus experiments.
3. **Measurement:** MTTD, MTTR, data loss, user impact.
4. **Analysis:** Findings, action items.

**Example scenario:**
```markdown
## GameDay: API Resilience
### Goals
- API survives Redis failure.
- Alert arrives within <1 min.
- Recovery within <5 min.

### Results
| Metric | Target | Actual |
|---------|------|------|
| Alert | <1 min | 45 sec |
| MTTR | <5 min | 3 min |
| User impact | None | 2% 5xx |
```

**Tools:** Chaos Mesh, Litmus, Gremlin, AWS FIS.

DevOps: What is GameDay in Chaos Engineering?