ec2 reserved instances 大降价了

今天收到Amazon的邮件，说 EC2 reserved instances 降价37%，偶又上网对比了 on-demand 和 与reserved 的不同，找到了：

http://www.semicomplete.com/blog/geekery/ec2-reserved-vs-ondemand

里面非常清楚的表示出了，在降价前，半年的on-demand的价格就已经达到1年期的reserved，而9个月的on-demand则达到了3年的reserved 的价格。

于是偶毅然购买了reserved.

这里有一个小知识点与大家分享：

如果你购买的 reserved instance 与 原 on-demand的类型相同（比如都是micro），而且地点相同（比如都在新加坡的ap-southeast-1a），那么Amazon会自动的把原先购买的on-demand 实例转化成reserved类型的。你不需要做任何额外的操作，也不用更换Key或者修改域名的A记录什么的。

下面是他们的解释：

https://forums.aws.amazon.com/message.jspa?messageID=232204

Hi Kito D. Mann,
As D. Johansson correctly described, the conversion of an on-demand instance to a reserved instance is purely a billing issue. Simply buy a reserved instance, and the instances will be billed as reserved instance. No changes need to be made to your AutoScaling group.

Please note that reserved instances currently need to be purchased for a specific AZ. In order to get the benefit of reserved instance pricing, your AutoScaling group should be configured to launch instances in those AZs.

For example, if you only buy a reserved instance in us-east-1a, you should setup your AutoScaling group to launch instances in us-east-1a. If your AutoScaling group is configured to launch instances in us-east-1a and us-east-1b, and AutoScaling launches an instance in us-east-1b, it will be billed as an on-demand instance unless you also buy a reserved instance in us-east-1b.

I hope that helps.
Suor

你还在犹豫什么？最新的价格：

一年期只有23美金；三年期45美金

而且大陆访问新加坡/日本速度是比较快的，SSH几乎没什么延迟。Ping值也非常小，你可以亲自试试：http://www.cloudping.info/