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Amazon EBS Snapshot 支援 Lifecycle Management

以往用 Amazon EBS Snapshot 需要用 Lambda 當 cron job 建立 snapshot,以及管理要存的數量 (要刪掉舊的),現在 AWS 直接提供服務幫你處理:「New – Lifecycle Management for Amazon EBS Snapshots」。文章的截圖就說明了這個新功能:

不收另外的費用,不過目前只有開放三區,東京不在裡面:

You can create and use Data Lifecyle Manager policies at no charge; you pay the usual storage charges for the EBS snapshots that it creates.

Data Lifecycle Manager is available in the US East (N. Virginia), US West (Oregon), and EU (Ireland) Regions.

先繼續用 Lambda,等東京有的時候再換過去...

Amazon EFS 開放東京區使用,提供 Provisioned Throughput

兩篇 Amazon EFS 的消息:「Amazon Elastic File System (Amazon EFS) Available in Asia Pacific (Tokyo) Region」、「Amazon EFS Now Supports Provisioned Throughput」。

ap-northeast-1 等很久的功能終於上線了,另外本來 EFS 對速度是有限制的,現在則是提供付費方案讓你可以確保效能... (採用 credit 架構,不過一般是夠用的... 空間在 1TB 以下可以 burst 到 100MB/sec,參考「Throughput Modes」這篇的說明)

這樣有蠻多架構可以花錢來解了...

EBS 可以動態擴充 Magnetic Volume 的大小了...

AWS 宣佈可以動態擴充 EBS (Magnetic Volume) 的大小了:「Amazon EBS Extends Elastic Volumes to Support EBS Magnetic (Standard) Volume Type」。EBS (Magnetic Volume) 被歸類到前個世代的產品,意外的把這個功能支援了前個世代的產品...

前世代的 Magnetic Volume 與 Throughput Optimized HDD (st1) & Cold HDD (sc1) 來比較起來貴了一些,但可以當作開機空間,另外低消只有 1GB (而 st1sc1 是 500GB),不過如果與 General Purpose SSD (gp2) 比的話,只要 I/O 有點量,整體的價錢就會超過 gp2,目前看起來還是用 gp2 會好一些...

Amazon EFS 在首爾先開了...

Amazon EFS 其實就是 AWS 提供的雲端版 NFS 或是 CIFS,這對於某些應用來說很好用,尤其效能不是主要考量時,像是從外面買來的商用軟體需要找個空間放資料...

不過沒想到在亞洲第一個開的點居然是首爾 (i.e. ap-northeast-2):「Amazon Elastic File System (Amazon EFS) Available in Asia Pacific (Seoul) Region」。

提到 AWS 的首爾區,台北過去的直線距離雖然比大阪與東京都近,但各家的路由都是從日本繞過去,不然其實首爾的點應該會是台灣的首選... 不曉得北京與上海到首爾的連線情況又是如何,找機會開台機器測試看看。

ALB 支援 Slow Start 了

這個功能在 ELB Classic 年代時有跟 AWS 提過,到 ALB 支援了 (總算...):「Application Load Balancer Announces Slow Start Support for its Load Balancing Algorithm」。

Application Load Balancers now support a slow start mode that allows you to add new targets without overwhelming them with a flood of requests. With the slow start mode, targets warm up before accepting their fair share of requests based on a ramp-up period that you specify.

然後時間可以設定,從 30 秒到 15 分鐘:

Slow start mode can be enabled by target group and can be configured for a duration of 30 seconds to 15 minutes. The load balancer linearly increases the number of requests sent to a new target in a target group up to its fair share during the slow start ramp-up window.

就之前的經驗來說,這在跑 PHP 的時候會很需要這個功能 (之前是在 F5 的設備上設定)。其他的語言因為性質不太一樣,可能不會這麼吃這個功能。

主要是因為 PHP 是在 request 進來時 compile 並且 cache。所以在機器剛起來時,儘量將 CPU 留給 opcache,把常用的頁面 compile 完並且放進 cache,而不是讓大量的連線灌進來,這樣對使用體驗不會太好... (要避免 CPU 吃滿 100% 很久,造成每個連線都很慢才跑完)

AWS 推出 Slow Start 後對 auto scaling 時的順暢度會好不少...

Amazon ECS 與 AWS Fargate 都納入 Amazon Compute SLA 計算

AWS 宣佈的這兩個服務 (Amazon ECSAWS Fargate) 都納入 99.99% 的 SLA 合約範圍:「Amazon Compute Service Level Agreement Extended to Amazon ECS and AWS Fargate」。

Amazon Elastic Container Service (Amazon ECS) and AWS Fargate are now included in the Amazon Compute Service Level Agreement (SLA) for 99.99% uptime and availability.

ECS 已經跑一陣子了可以理解,但 Fargate 的概念算比較新,剛出來沒多久就決定放進去比較意外...

AWS 提昇了 Amazon EBS 能提供的效能上限

AWS 宣佈 Amazon EBS 可以提供的效能往上提高了 (這邊講的是 Provisioned IOPS SSD,代號 io1):「Amazon EBS Improves Performance for io1 Volumes」。

單一 volume 的 IOPS 從 20K 變成 32K,thoughput 從 320MB/sec 變成 500MB/sec:

Today we are announcing an improvement in performance of Provisioned IOPS SSD (io1) Volumes from 20,000 IOPS to 32,000 IOPS and from 320 MB/s to 500 MB/s of throughput per volume.

應該是科技的進步帶動的 XD

Amazon EKS 與 AWS Fargate

在今年的 AWS re:Invent 2017 上宣佈 Amazon ECS 也支援 Kubernetes,也就是 Amazon EKS:「Amazon Elastic Container Service for Kubernetes」,一個用的人夠多就支援的概念...

目前這個服務還在 Preview,所以要申請才能用:

Amazon EKS is available in Preview. We look forward to hearing your feedback.

另外一個在 AWS re:Invent 2017 上宣佈的是 AWS Fargate,讓你連 Amazon ECS 或是 Amazon EKS 都不用管的服務,直接按照 container 的大小收費:「Introducing AWS Fargate – Run Containers without Managing Infrastructure」、「AWS Fargate: A Product Overview」。

第一個有疑慮的點是,是否會跟其他人共用相同的 host,也就是 isolation 的程度。這點在 AWS 的人在 Hacker News 上的這邊有回覆,在不同的 cluster 上不會使用同樣的底層:

NathanKP 4 days ago [-]
Fargate isolation is at the cluster level. Apps running in the same cluster may share the underlying infrastructure, apps running in different clusters won't.

另外也提到每個 cluster 都是使用者自己產生的:

NathanKP 3 days ago [-]
A customer creates a cluster on their account. You as a customer can create one or more Fargate clusters on your account to launch your containers in.

不是很正面的回覆,而且不是在官方的 forum 回的,安全性就要大家自己判斷了...

另外也有有提到與 Amazon EC2 相比,價錢當然會比較貴,但可以預期會降低 engineer 的時間成本:

NathanKP 4 days ago [-]
AWS employee here. Just want to say that we actually had a typo in the per second pricing on launch. The actual pricing is:
$0.0506 per CPU per hour
$0.0127 per GB of memory per hour
Fargate is definitely more expensive than running and operating an EC2 instance yourself, but for many companies the amount that is saved by needing to spend less engineer time on devops will make it worth it right now, and as we iterate I expect this balance to continue to tip. AWS has dropped prices more than 60 times since we started out.

目前只能接 Amazon ECS,預定 2018 可以接 Amazon EKS:

I will tell you that we plan to support launching containers on Fargate using Amazon EKS in 2018.

而目前這個版本 (可以接 Amazon ECS 的版本) 在 us-east-1 已經開放了:

Fargate is available today in the US East (Northern Virginia) region.

Amazon EFS 推出 File Sync 服務

先前 Amazon EFS 需要找台機器掛上去再同步 (無論是 EC2 的機器還是透過 VPN 將自己的機器接上去),現在推出可以直接把檔案同步進去的服務了:「Sync Files to Amazon Elastic File System Quickly, Easily and Securely with EFS File Sync」。

不過不是所有提供 Amazon EFS 的區域都有,目前只有 us-east-1us-east-2us-west-2 以及 eu-west-1

EFS File Sync is available in the US East (N. Virginia), US East (Ohio), US West (Oregon), and EU (Ireland) regions, with availability in the EU (Frankfurt) and Asia Pacific (Sydney) regions coming in December 2017.

另外這是有費用的,目前有提供的四區都是 USD$0.01/GB。

AWS 提供 Hybrid Cloud 環境下 DNS 管理的說明

不知道為什麼出現在 browser tab 上,不知道是哪邊看到的... AWS 放出了一份文件,在講 hybrid cloud 環境下當你同時有一般 IDC 機房,而且使用內部 domain 在管理時,網路與 AWS 打通後要怎麼解決 DNS resolver 的問題:「Hybrid Cloud DNS Solutions for Amazon VPC」。

有些東西在官方的說明文件內都寫過,但是是 AWS 的特殊設計,這邊就會重複說明 XDDD

像是這份文件裡提到 Amazon DNS Server 一定會在 VPC 的 base 位置加二 (舉例來說,10.0.0.0/16 的 VPC,Amazon DNS Server 會在 10.0.0.2):

Amazon DNS Server
The Amazon DNS Server in a VPC provides full public DNS resolution, with additional resolution for internal records for the VPC and customer-defined Route 53 private DNS records.4 The AmazonProvidedDNS maps to a DNS server running on a reserved IP address at the base of the VPC network range, plus two. For example, the DNS Server on a 10.0.0.0/16 network is located at 10.0.0.2. For VPCs with multiple CIDR blocks, the DNS server IP address is located in the primary CIDR block.

在官方文件裡,則是在「DHCP Options Sets」這邊提到一樣的事情:

When you create a VPC, we automatically create a set of DHCP options and associate them with the VPC. This set includes two options: domain-name-servers=AmazonProvidedDNS, and domain-name=domain-name-for-your-region. AmazonProvidedDNS is an Amazon DNS server, and this option enables DNS for instances that need to communicate over the VPC's Internet gateway. The string AmazonProvidedDNS maps to a DNS server running on a reserved IP address at the base of the VPC IPv4 network range, plus two. For example, the DNS Server on a 10.0.0.0/16 network is located at 10.0.0.2. For VPCs with multiple IPv4 CIDR blocks, the DNS server IP address is located in the primary CIDR block.

另外也還是有些東西在官方的說明文件內沒看過,像是講到 Elastic Network Interface (ENI) 對 Amazon DNS Server 是有封包數量限制的;這點我沒在官方文件上找到,明顯在量太大的時候會中獎,然後開 Support Ticket 才會發現的啊 XDDD:

Each network interface in an Amazon VPC has a hard limit of 1024 packets that it can send to the Amazon Provided DNS server every second.

Anyway... 這份文件裡面提供三種解法:

  • Secondary DNS in a VPC,直接用程式抄一份到 Amazon Route 53 上,這樣 Amazon DNS Server 就可以直接看到了,這也是 AWS 在一般情況下比較推薦的作法。
  • Highly Distributed Forwarders,每台 instance 都跑 Unbound,然後針對不同的 domain 導開,這樣可以有效避開單一 ENI 對 Amazon DNS Server 的封包數量限制,但缺點是這樣的設計通常會需要像是 Puppet 或是 Chef 之類的軟體管理工具才會比較好設定。
  • Zonal Forwarders Using Supersede,就是在上面架設一組 Unbound 伺服器集中管理,透過 DHCP 設定讓 instance 用。但就要注意量不能太大,不然 ENI 對 Amazon DNS Server 的限制可能會爆掉 XD

都可以考慮看看...

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