https://blog.wongcw.com/2022/05/12/google%e7%99%bc%e5%b8%839-exaflop%e7%ae%97%e5%8a%9b%e7%9a%84cloud-tpu-v4-pods%e9%9b%86%e7%be%a4%e4%b8%a6%e9%80%b2%e5%85%a5%e5%85%ac%e9%96%8b%e9%a0%90%e8%a6%bd%e9%9a%8e%e6%ae%b5/