amazon-web-services - 如何将 AWS EC2 实例与购买的预留实例关联？

Question

我们已为对我们的基础设施至关重要的 Amazon Elastic Compute Cloud (EC2) 实例购买了 Amazon Web Services (AWS) 预留实例。该实例每天以一定的时间间隔启动和停止。

我发现购买预留实例可以“保证”即使 AWS 负载很重，该实例也能可靠启动，但是有没有办法专门将此预留实例与我们想要关联的实例绑定(bind)起来？

如果我们添加另一个与我们购买的预留实例的条件完全匹配的实例，会发生什么情况？

Answer 1

您无需担心或执行任何操作来关联实例和购买的预留实例；所有这些都是由 AWS 自动完成。

预留实例纯粹是与计费和成本相关，与 EC2 实例的技术方面无关。如果您的任何正在运行的实例与您购买的任何预留实例相匹配，那么您将受益于降低的成本。对于涉及预留实例的 SLA 或实例级别的更改没有任何 promise 。当您有 2 个预留实例时，同样的情况也适用；如果您的帐户中运行着 2 个与您购买的预留实例相匹配的实例，则将应用降低的成本。

类比 - 超市优惠券优惠

If the Offer Says, buy 2 units of Product A and get one Product B absolutely Free. So you look into the offer and take 2 units of Product A and one Unit of Product B. During the billing as well, the Point of Sales Person also doesn't look into each and every product and try to check it offers; rather he or she directly keeps scaning each and every product against the bar-code scanner and that't it - when these 3 are scanned, the price for Free-Product is automatically reversed.

So similarly, you buy the Reserved Instance (Coupon) choosing the AMI, Region, AZ, Duration etc. You would do all your tech stuff as usual like deploying, patching, monitoring etc. During the billing, if the instance(s) you launched matches the Reserved Instance, then the Reserved pricing would be applied; if not that would be charged at 'On-Demand-Pricing'.

If there is a mismatch between what instance you are running and what instance you have reserved; you will not be using the benefit of Reserved-Instance pricing and be charged with On-Demand-Pricing. Also you will be wasting the investment done for the Reserved-Instance