====== Spot Instances ======

**What it is:** Spare EC2 capacity offered at a large discount, but AWS can reclaim it at any time.

**What it’s for:**
  * Fault-tolerant, interruptible workloads (batch processing, CI jobs).
  * Big cost savings when interruptions are acceptable.

**Key ideas:**
  * Can be interrupted with short notice.
  * Not suitable for critical workloads needing guaranteed availability.

**Exam cues:**
  * “batch jobs that can be stopped and resumed” → Spot.
  * “cheapest compute option” → Spot (with interruption tolerance).

**Hard words:**
  * *spare* /sper/: dư thừa
  * *reclaim* /rɪˈkleɪm/: thu hồi
  * *interruptible* /ˌɪntəˈrʌptəbl/: có thể bị ngắt
  * *fault-tolerant* /fɔːlt ˈtɑːlərənt/: chịu lỗi