====== Scaling Policy ======

**What it is:** Rules that tell an ASG when to scale out/in.

**What it’s for:**
  * Automatically match capacity to load.

**Common types:**
  * **Target tracking**: keep a metric near a target (e.g., CPU ~ 50%).
  * **Step scaling**: scale by steps when thresholds are crossed.
  * **Scheduled scaling**: scale at specific times.

**Exam cues:**
  * “keep average CPU at 40%” → target tracking.
  * “scale every day at 9am” → scheduled scaling.

**Hard words:**
  * *threshold* /ˈθreʃhoʊld/: ngưỡng
  * *scheduled* /ˈskedʒuːld/: theo lịch