What it is: The process where Auto Scaling removes unhealthy instances and adds replacements to keep desired capacity.
What it’s for:
Default behavior (exam detail):
ASG creates a scaling activity to terminate the unhealthy instance first.
Then (while/after termination), another scaling activity launches a new instance to replace it. :contentReference[oaicite:6]{index=6}
Note:
Hard words:
*terminate* /ˈtɝːmɪneɪt/: chấm dứt (tắt/huỷ instance)
*replace* /rɪˈpleɪs/: thay thế
*maintenance policy* /ˈmeɪntənəns ˈpɑːləsi/: chính sách bảo trì