tiering

Amazon EFS 這次推出的是再多推出一個 storage class：「Optimize your storage costs for rarely-accessed files with Amazon EFS Archive」。

先前應該是 2019 的時候推出了 IA：「Amazon EFS 的 IA Storage Class」，現在的 Archive 就是新的 storage class，儲存成本更便宜，但取用成本更高。

以 us-east-1 的價錢來看，可以到 Archive 的成本是 IA 的一半：

Standard (GB-Month)	$0.30
Infrequent Access (GB-Month)	$0.016
Archive (GB-Month)	$0.008
Backup - Warm / Cold (GB-Month)	$0.05 / $0.01

讀取成本則是 IA 的三倍：(這邊的 Tiering 指的是自動化的搬遷的服務)

All storage classes - Reads (per GB transferred)	$0.03
All storage classes - Writes (per GB transferred)	$0.06
Infrequent Access - Reads (incremental charge per GB transferred)	$0.01
Infrequent Access - Tiering (per GB transferred)*	$0.01
Archive - Reads (incremental charge per GB transferred)	$0.03
Archive - Tiering (per GB transferred)*	$0.03

基本上就是 Amazon S3 那套分級方法陸陸續續搬過來的感覺。

然後注意到這個「Regional (Multi-AZ) with Elastic Throughput」是新的計價方案，就算是 Standard storage class，I/O 是要算錢的。

在舊的方案「Regional (Multi-AZ) with legacy throughput modes」裡面，Standard 的 I/O 是不用額外付費，已經包在裡面，除非你直接購買 Provisioned (保證速度)：

Standard (GB-Month)	$0.30
Infrequent Acces (GB-Month)	$0.025
Backup - Warm / Cold (GB-Month)	$0.05 / $0.01

Provisioned Throughput (MB/s-Month)	$6.00
Infrequent Access - Reads (per GB transferred)	$0.01
Infrequent Access - Tiering (per GB transferred)*	$0.01

翻了一下 Internet Archive 可以確認前幾天 2023/11/26 的 pricing 頁面還是舊的，也就是說這是這次推出來的改變：「Amazon EFS Pricing」。

看了一下目前 blog 上最近掛 Amazon EFS 類別的三篇都沒提到這件事情 (「New – Announcing Amazon EFS Elastic Throughput」、「Optimize your storage costs for rarely-accessed files with Amazon EFS Archive」以及「Replication failback and increased IOPS are new for Amazon EFS」)，要用的人自己注意一下？

Amazon S3 推出了新的 Storage Class，後面直接用演算法分析 access pattern (所以要跑一陣子才會生效)，然後決定要放到 Standard 或是 Standard IA 裡：「Announcing S3 Intelligent-Tiering — a New Amazon S3 Storage Class」。

混了 Standard 與 Standard IA：

S3 Intelligent-Tiering stores objects in two access tiers: one tier that is optimized for frequent access and another lower-cost tier that is optimized for infrequent access.

然後連續 30 天沒有被存取的就會被丟到 Standard IA，如果有被存取的話就會被搬回來，而搬移的部份不用收費：

For a small monthly monitoring and automation fee per object, S3 Intelligent-Tiering monitors access patterns and moves objects that have not been accessed for 30 consecutive days to the infrequent access tier. There are no retrieval fees in S3 Intelligent-Tiering. If an object in the infrequent access tier is accessed later, it is automatically moved back to the frequent access tier. No additional tiering fees apply when objects are moved between access tiers within the S3 Intelligent-Tiering storage class.

從費用上可以看到演算法本身是有費用的，換算一下 1M objects 是 USD$2.5/month，好像還可以...

Monitoring and Automation, All storage / Month $0.0025 per 1,000 objects

不過有蠻多要注意的 pattern。像是這邊有提到 128KB 以下的檔案不會搬到 IA 上，但不知道算不算 Monitoring 的費用？

S3 Intelligent-Tiering has a minimum eligible object size of 128KB for auto-tiering. Smaller objects may be stored but will always be charged at the Frequent Access tier rates.

另外這邊講 S3 Intelligent-Tiering 的三十天也不知道是不是 Standard + Standard IA，或是分開算：

S3 Intelligent-Tiering, S3 Standard-IA, and S3 One Zone-IA storage are charged for a minimum storage duration of 30 days.

可以先觀望一下...