====== Route 53 Routing Policies ======

**What it is:** Strategies Route 53 uses to answer DNS queries with the “best” record.

**What it’s for:** Control how traffic is distributed across endpoints.

**Common routing policies (exam staples):**
  * **Simple**: single record response.
  * **Weighted**: split traffic by percentage (A/B test).
  * **Latency-based**: route to lowest-latency Region.
  * **Failover**: primary/secondary with health checks.
  * **Geolocation**: route by user location.
  * **Multi-value**: return multiple healthy records.

**Exam cues:**
  * “gradually shift 10% traffic to new version” → Weighted.
  * “route users to closest Region” → Latency-based.
  * “active-passive DNS failover” → Failover routing policy.

**Hard words:**
  * *weighted* /ˈweɪtɪd/: theo trọng số
  * *latency-based* /ˈleɪtənsi beɪst/: dựa trên độ trễ
  * *failover* /ˈfeɪlˌoʊvər/: chuyển dự phòng
  * *geolocation* /ˌdʒiːoʊloʊˈkeɪʃn/: định vị địa lý
  * *gradually* /ˈɡrædʒuəli/: dần dần