Amazon EC2 的 t3/t3a/t4g 的 CPU credit 保留七天的限制

Twitter 上看到朋友提到 t3 系列的機器有保留七天的 CPU credit:

在「CPU credits and baseline utilization for burstable performance instances」這邊有提到,t3/t3a/t4g 的設計都是讓你可以塞 24h 小時的量:

這邊講的七天是這段:

CPU credits on a running instance do not expire.

For T2, the CPU credit balance does not persist between instance stops and starts. If you stop a T2 instance, the instance loses all its accrued credits.

For T3 and T4g, the CPU credit balance persists for seven days after an instance stops and the credits are lost thereafter. If you start the instance within seven days, no credits are lost.

開著的機器的 CPU credit 不會過期,只會到最大上限 (在同一篇文件裡面的表格有提到),t2 的機器關掉後 (stop) CPU credit 就會直接消失,而 t3/t3a/t4g 則在關掉後會保留七天。

之前沒注意到文件上的這點。

另外之前在測試自己架設 Sentry 時還測過 t3a.medium -> r5a.large -> t3a.medium 這樣換過去又換回來的情況,本來的 CPU credit 是可以繼續用的,看起來 CPU credit 不會因為 family type 改變就不見 (不過不確定這個是不是 undefined behavior...)。

AWS 推出使用 AMD CPU 的 t3a.*

AWS 推出了 t3a.* 的 EC2 instance:「Now Available – AMD EPYC-Powered Amazon EC2 T3a Instances」。

目前開放的區域有限,但算是個開始:

You can launch T3a instances today in seven sizes in the US East (N. Virginia), US West (Oregon), Europe (Ireland), US East (Ohio), and Asia Pacific (Singapore) Regions in On-Demand, Spot, and Reserved Instance form.

價錢大約再低個 10% 左右:

Pricing is 10% lower than the equivalent existing T3 instances; see the On-Demand, Spot, and Reserved Instance pricing pages for more info.

有些超小的機器可以考慮重開的時候就順便換過去...