AWS Global Accelerator 的 TCP 協定

AWS Global Accelerator 是讓使用者先連到最近的 AWS 節點,再透過 AWS 的骨幹網路連到服務上 (可以參考之前寫的「AWS 推出 Global Accelerator,用 AWS 的網路加速」這篇),當時就有說支援 TCP 與 UDP,但剛剛看到「AWS Global Accelerator launches TCP Termination at the Edge」這篇的時候才注意到,本來的產品是把 TCP 封包當作 UDP 在處理,也就是 TCP 3-way handshake 還是要到服務節點本身處理。

現在這個 TCP Termination 的功能則是先在最近的節點上建立 TCP 連線,然後同時往後端的建立連線接起來:

Typically, a TCP connection is established by using a three-way handshake (that is, three messages) between the client on the internet and the application endpoint in the AWS Region. So the farther away the client is from the endpoint, the longer the initial connection setup takes. With TCP termination at the edge, Global Accelerator reduces initial setup time by establishing a TCP connection between the client and the AWS edge location closest to the client. At nearly the same time, Global Accelerator creates a second TCP connection between the edge location and the application endpoint in the AWS Region. With this process, the client gets a faster response from the Global Accelerator edge location, and the connection from the edge location to the application endpoint in the Region is optimized to run over the AWS global network.

這樣連線的速度就會更快,但有可能會有前面建起來但後面建不起來的情況需要處理,一般的應用程式應該還好,畢竟地球上有個 GFW 也常幹這種事情...

AWS 大阪區要轉成正式區域

看到 AWS 公佈了大阪區要轉成正式區域的消息:「In the Works – AWS Osaka Local Region Expansion to Full Region」。

大阪區本來是東京區的 local region,主要是提供給東京區的用戶備份以及備援,現在如果變成 full region 的話可以觀察看看 routing,如果從日本西側進骨幹的話,有機會快個 4ms (直線約 400km)?


目前喊出來的目標是 2021 年年初會有 3 AZ,也就是標準 region 的架構:

Today, we are excited to announce that, due to high customer demand for additional services in Osaka, the Osaka Local Region will be expanded into a full AWS Region with three Availability Zones by early 2021.

AWS Outposts 總算要開始出貨了

去年 AWSre:Invent 喊的 AWS Outposts 總算是有東西要出貨了:「AWS Outposts Now Available – Order Yours Today!」。

放在自家實體的機櫃,然後掛到 AWS 上變成一個特殊的 region。目前一個特殊的 region 只能放 16 個機櫃,但預期之後可以更多:

Capacity Expansion – Today, you can group up to 16 racks into a single capacity pool. Over time we expect to allow you to group thousands of racks together in this manner.

不過要注意的是,需要有 AWS Enterprise Support 才能下單,而且看起來硬體的維修也包在內了:

Support – You must subscribe to AWS Enterprise Support in order to purchase an Outpost. We will remotely monitor your Outpost, and keep it happy & healthy over time. We’ll look for failing components and arrange to replace them without disturbing your operations.

看了一下價錢的頁面,如果以北美的 upfront 來算,最便宜的是 OR-L8IF4WFOR-I0OGL02 的 USD$225,504.81,最貴的是 OR-HSZHMMF 的 USD$898,129.52,暫時應該用不到 XDDD

AWS 在 us-west-2 開 Local Zone

AWS 宣佈 us-west-2 (Oregon) 開 Local Zone,這應該是 AWS 第一次在美國開 Local Zone,上次看到好像是 ap-northeast-1 (Tokyo) 的 Osaka 區:「AWS Now Available from a Local Zone in Los Angeles」。

控制都還是在 us-west-2 的範圍控制,但代碼會是 us-west-2-lax-1a (目前只有一區),之後會開 us-west-2-lax-1b (第二區):

In the fullness of time (as Andy Jassy often says), there could very well be more than one Local Zone in any given geographic area. In 2020, we will open a second one in Los Angeles (us-west-2-lax-1b), and are giving consideration to other locations. We would love to get your advice on locations, so feel free to leave me a comment or two!

剛剛登入進去 VPC 的 Subnets 想要增加看看,沒看到 us-west-2-lax-1a 的選項可以選,看起來還是需要另外申請?

另外算了一下 Oregon (用 Portland 算) 到 Los Angels 的直線距離,大約要 1300km 左右 (比台北到香港還遠不少),光速單趟大約要 6.5ms?這樣對一些應用程式應該是會有感覺...

This Local Zone is designed to provide very low latency (single-digit milliseconds) to applications that are accessed from Los Angeles and other locations in Southern California.


Amazon Aurora MySQL 5.7 也可以上 Global Database 了

AWSAmazon Aurora MySQL 5.7 版本推出了 Amazon Aurora Global Database:「Aurora Global Database is Now Supported on Amazon Aurora MySQL 5.7」。

看起來 MySQL 系的 Global Database 就是跨區的 master-slave 架構 (所以標榜降低了 read latency,但沒有提到 write latency):

An Amazon Aurora Global Database is a single database that spans multiple AWS regions, enabling low latency global reads and disaster recovery from region-wide outages.

另外可以看到是 1 秒,所以應該是 async replication:

Aurora Global Database replicates writes in the primary region with typical latency of <1 second to secondary regions, for low latency global reads.


In disaster recovery situations, you can promote the secondary region to take full read-write responsibilities in under a minute.


Amazon S3 的 Replication 也給出 SLA 了

Amazon S3 的 cross-region replication 與 same-region replication 也提供 SLA 了:「S3 Replication Update: Replication SLA, Metrics, and Events」。

  • Most of the objects will be replicated within seconds.
  • 99% of the objects will be replicated within 5 minutes.
  • 99.99% of the objects will be replicated within 15 minutes.


When you enable this feature, you benefit from the associated Service Level Agreement. The SLA is expressed in terms of a percentage of objects that are expected to be replicated within 15 minutes, and provides for billing credits if the SLA is not met:

  • 99.9% to 98.0% – 10% credit
  • 98.0% to 95.0% – 25% credit
  • 95% to 0% – 100% credit

不過只保證 99% 的物件在五分鐘內會被 replicate 有點低,應該跟底層的網路 latency 有關?

AWS Ground Station 增加了巴林的基地站

先前 AWS Ground Station 提供的地面站都在美國 (美東與美西),這代表有些衛星就打不到了... 這次宣佈增加中東巴林的點,差不多是美西的對面,也因此增加了不少涵蓋率:「AWS Ground Station is now available in Middle East (Bahrain) region」。

雖然現在的公司有在用衛星,但以價錢與支援的頻帶看起來,應該連測試都沒機會... XD

Amazon SES 增開三區...

Amazon SES 居然加開服務區域了:「Amazon SES is Now Available in Three Additional AWS Regions」。

當初猜測一直沒增加的原因是法規的問題,各國對於 spam 的處理方式不同,有些地區可能會導致 AWS 有連帶責任之類的。這次還是沒開日本與新加坡,看起來應該也是評估後覺得不會有問題的才開:

Amazon Simple Email Service (Amazon SES) is now available in the Asia Pacific (Mumbai), Asia Pacific (Sydney), and EU (Frankfurt) Regions, in addition to the US East (Virginia), US West (Oregon), and Europe (Ireland) regions.


Amazon S3 推出同一個區域的同步複製功能

Amazon S3 推出了 Same-Region Replication:「Amazon S3 introduces Same-Region Replication」。

先前的功能只有 Cross-Region Replication,可以當作異地備份的功能,現在則是推出讓同一區也可以複製...


Replicated objects can be owned by the same AWS account as the original copy or by different accounts, to protect from accidental deletion.

AWS 中東區巴林開幕

AWS 開了中東區,在巴林:「Now Open – AWS Middle East (Bahrain)」,現在的標配都是 3 AZs 了:

The Middle East (Bahrain) Region consists of three Availability Zones (AZ’s). Having three Availability Zones enables Middle East organizations to meet business continuity and disaster recovery requirements and also build highly available, fault-tolerant, and scalable applications.

翻了一下之前的計畫,中東區本來是預定 2019 上半年要提供,看起來稍微 delay 了 (不過比香港區好很多了):「AWS 將在阿拉伯聯合大公國擴點」。