專案到某個規模，會有很多事情要考量
- 如何快速獲得市場
- 我的設計能否支撐我預期的 scale
在 scale 的 issue 中，其中就是要想你的 infrastructure 的 cost
這邊作者提出他常用的一些參考數字
並非精準的數字，但可以用來評估了
有些公司還有 AWS 的 discounts，所以數字也有機會蠻大的差異
整理表 ec2instances.info
這邊的參考數字是 eu-west-1 region
| Median monthly cost | |
|---|---|
| 1 modern vCPU (4 AWS ECUs) | 58 $/month |
| With 1 year convertible reservation (all up front) | 43 $/month |
| With 3 years convertible reservation (all up front) | 30 $/month |
| With spot pricing (estimated) | 30 $/month |
AWS represents the computing power of its machines in Elastic Compute Units, and 4 ECUs represent more or less the power of a modern CPU. So the prices above are for one CPU or core, not one instance.
Here’s the price of 1 ECU in $ per hour across all instance types I looked at:
如果規劃是
- low latency
- high throughput
- planning to store everything in Redis
那除了上面 CPU 的 $ 之外，還要付 RAM 的費用
Elasticache
- is more or less twice as expensive for on-demand
- but prices drop quite quickly when looking at reserved instances.
| Median monthly cost | |
|---|---|
| 1 GB RAM | 10 $/month |
| 1 GB RAM 1 year convertible reservation (all up front) | 8 $/month |
| 1 GB RAM 3 years convertible reservation (all up front) | 5 $/month |
| SSD | 0.11 $/month |
| Hard Disk | 0.05 $/month |
| S3 | 0.02 $/month |
| S3 Glacier | 0.004 $/month |
這邊是純粹的 storage cost
- 所以要思考你的 data usage patterns 是什麼？
- How much CPU will you need to run that in-memory database 24/7?
S3 也是一樣
- how much will you pay in writing/reading requests?
要提供 data 給 end users 或需要跨區的，就要思考這邊
| Type of data transfer | Cost of transferring 1GB |
|---|---|
| EU/US region to any other region | 0.02 $/GB |
| APAC region to any other region | 0.09 $/GB |
| EU/US region to Internet | 0.05 $/GB |
| APAC region to Internet | 0.08 $/GB |
| Between two AZs in the same region | 0.01 $/GB |
| Inside the same AZ | Free |
- AWS 重要的不是價格實惠
- AWS 重要的是架構、backup、emergency deployment
特定情境下（網站提供漫畫看）
- pushing over 1PB/month of images
- at the lowest rate of $0.02/GB with cloudfront/S3
- it would be $20,000 per month
- bandwidth cost is stupid expensive on AWS
But they ended up paying nothing by using cloudflare who gave them unmetered bandwidth.
until they got throttled earlier this year but they got out of that by upgrading to a measly $200/month plan
這 case 跟很多 case 一樣，都說明的 CDN 大幅降低成本，聽到的幾乎都說可以省 70% 以上...
關於 bandwidth
- Over 10tb of transfer you can (and should) negotiate some cheaper pre-committed pricing on bandwidth.
慢慢接觸吧，這些要碰的人才有感受