Raspberry Pi 4 的 Type C 無法使用 Macbook Charger 供電的問題

Raspberry Pi 4 出來後有些災情 (畢竟又加了不少東西近去),在 Hacker News 上看到的 Type C 介面的充電問題:「Raspberry Pi 4 not working with some chargers (scorpia.co.uk)」,引用的原文可以在「Pi4 not working with some chargers (or why you need two cc resistors)」這邊看到,裡面提到了新的 Type C 供電介面在接某些充電器時不會供電 (包括了 Macbook 的充電器):

The new pi has been released and it has a USB Type-C connector for power however people are finding some chargers are not working with it (notably macbook chargers). Some have speculated that this is due to a manufacturer limitation on the power supplies however it is actually due to the incorrect detection circuitry on the Pi end of the USB connection.

這樣說有點偏頗,但是 Macbook 的充電器一向是 Type C 裡的指標,如果這顆充電器跟其他裝置配合上有問題,通常都是代表其他裝置的實作有問題... (噗)

這次發現的電阻問題看起來有點苦 (看起來需要改版子),目前文章作者建議的 workaround 主要就是「不要用那麼好的設備」,比較簡單的包括了 Type C 的線不要那麼好 (像是找充手機用的線就好,不要找拿可以跑 5A 的線),或是透過 Type A 轉 Type C 的線也應該可以避開這個問題,最差的情況應該是找其他的充電器:

Now onto some solutions. Assuming the issue you are having is caused by the problem discussed above, using a non e-marked cable (most USB-C phone charger cables are likely this type) rather than an e-marked cable (many laptop charger/thunderbolt cables and any 5A capable cable will be in this category) will allow for the pi to be powered. In addition using older chargers with A-C cables or micro B to C adaptors will also work if they provide enough power as these don’t require CC detection to provide power. Ultimately though the best solution in the long run will be for there to be a board revision for the pi 4 which adds the 2nd CC resistor and fixes the problem.

對於已經入手的人,如果真的中獎,workaround cost 應該還在可以控制的範圍...

AWS 推出新的 Bare Metal Instances

AWS 針對各個 family type 都推出 Bare Metal 版本:「Now Available – Five New Amazon EC2 Bare Metal Instances: M5, M5d, R5, R5d, and z1d」。

AWS 第一次推出 Bare Metal 版本是在 2017 年年末推出的 i3.metal:「Amazon EC2 推出第一款 Bare Metal 的 Instance」,這樣算一算也一年多了,這次算是補產品線...

要注意的是,這次推出依照區域有不同的機種,像是 Ohio 沒有 z1d.metal 但有其他四種,N. California 則是沒有 m5d.metal 但有其他四種... 要先看一下表格才能確認每一區的情況 @_@

EC2 開始陸續推出支援 100Gbps 網路的機器

AWS 開始陸陸續續在推出有 100Gbps 能力的 EC2 instance 了:「New – EC2 P3dn GPU Instances with 100 Gbps Networking & Local NVMe Storage for Faster Machine Learning + P3 Price Reduction」。

從「Amazon EC2 Instance Types」這邊可以看到先前只有 c5n.18xlarge 有支援 100Gbps 網路,現在推出的 p3dn.24xlarge 是第二個支援的...

另外是 P3 系列的降價消息,比較奇怪的是從 2018/12/06 開始生效,而不是從月初開始。另外區域與條件也有一些複雜,有常在用的人可以翻一下說明...

Amazon EC2 推出 T3 系列機器了...

Amazon EC2 推出新的 family type,T3 系列了:「Introducing Amazon EC2 T3 Instances」。

官方宣稱比 T2 系列的機器快 30%:

T3 instances also feature the latest 2.5 GHz Intel Xeon Scalable processors which combined with the AWS Nitro System result in up to a 30% better price to performance improvement over T2 instances.

另外 T3 低階系列的機器 (t3.nanot3.microt3.small) 都是 2 vCPU 了,而且「CPU credits earned per hour」是原來的兩倍,但 t3.mediumt3.large 就跟原來一樣了,而再更大台的 t3.xlarget3.2xlarge 又比較大了... (參考「CPU Credits and Baseline Performance」)

另外是價錢上的差異,T3 的單價反而比 T2 低了一些:以 us-east-1 來看,t3.nano 是 USD$0.0052/hr,而 t2.nano 則是 USD$0.0058/hr,大約是 10% 的差距。

Reserved Instance 也是類似的情況,t3.nano 是 USD$27/y 與 USD$51/3y,t2.nano 則是 USD$29/y 與 USD$57/3y。

這次發佈把台灣團隊常用的區域都納入了,包括了北美的 us-east-1 (北維吉尼亞)、us-west-2 (奧勒崗) 與亞洲的 ap-northeast-1 (東京)、ap-southeast-1 (新加坡):

Amazon EC2 T3 Instances are available immediately in the US East (N. Virginia), US East (Ohio), US West (N. California), US West (Oregon), Canada (Central), Asia Pacific (Singapore), Asia Pacific (Sydney), Asia Pacific (Tokyo), Europe (Frankfurt), Europe (Ireland), Europe (London), and South America (Sao Paulo) AWS Regions.

現有的機器都可以考慮換過去了... 這也是買三年 RI 最好的時機了 XD

Amazon Elasticsearch 支援 I3 instance (i.e. 1.5 PB Disk) 了

Amazon Elasticsearch 支援 I3 instance 了:「Run Petabyte-Scale Clusters on Amazon Elasticsearch Service Using I3 instances」。

Amazon Elasticsearch Service now supports I3 instances, allowing you to store up to 1.5 petabytes of data in a single Elasticsearch cluster for large log analytics workloads.

i3.16xlarge 單台是 15.2 TB 的硬碟空間,100 台就會是 1.5 PB,不知道跑起來會多慢 XDDD

Amazon Elasticsearch Service – Amazon Web Services (AWS) | FAQs 這邊還沒修正 XD:

You can request a service limit increase up to 100 instances per domain by creating a case with the AWS Support Center. With 100 instances, you can allocate about 150 TB of EBS storage to a single domain.

Percona 分析在 AWS 上跑 Percona XtraDB Cluster 的效能 (I/O bound)

Percona 的人分析了在 Amazon EC2 上跑 Percona XtraDB Cluster (PXC) 效能 (I/O bound):「Best Practices for Percona XtraDB Cluster on AWS」。

先看他們做出來的圖:

直接跳到結論的地方。如果資料可以掉,用 i3 本地 storage 的效能是最好的,如果要資料不能掉,用 EBS 的 Provisioned IOPS SSD (io1) 的效能會比 General Purpose (gp2) 好很多。

另外 instance type 的選擇上,避免用 {i3,r4}.large,因為測試出來發現 {i3,r4}.xlarge 的效能好不只一倍。

不過 Aurora 的 Multi-master 已經在 Preview 了啊,如果 Percona 的人拿到帳號的話,應該會有單位成本的效能比較可以看...

Amazon EC2 再推出兩款新機種:M5 與 H1

Amazon EC2 的新機種發表:「M5 – The Next Generation of General-Purpose EC2 Instances」、「H1 Instances – Fast, Dense Storage for Big Data Applications」。

M5M4 的後續機種 (General Purpose),所以就沒什麼特別好講的了... H1 則是與 D2 接近,而且也應該算是後繼的機種 (Dense Storage),看了看內容感覺只是個升級 (雖然給他一個新的 family type),所以也沒什麼好講...

然後支援的地區都很少...

M5 三區:

You can launch M5 instances today in the US East (Northern Virginia), US West (Oregon), and EU (Ireland) Regions in On-Demand and Spot form (Reserved Instances are also available), with additional Regions in the works.

H1 四區:

H1 instances are available today in the US East (Northern Virginia), US West (Oregon), US East (Ohio), and EU (Ireland) Regions.

產品發表會固定會有的升級 XD

Amazon EC2 推出第一款 Bare Metal 的 Instance

Amazon EC2 直接租整台主機出來了:「Amazon EC2 Bare Metal Instances with Direct Access to Hardware」。

Bare Metal 怎麼翻譯比較好啊?雖然知道是拔掉虛擬化的主機... 裸奔機?

We knew that other customers also had interesting use cases for bare metal hardware and didn’t want to take the performance hit of nested virtualization. They wanted access to the physical resources for applications that take advantage of low-level hardware features such as performance counters and Intel® VT that are not always available or fully supported in virtualized environments, and also for applications intended to run directly on the hardware or licensed and supported for use in non-virtualized environments.

反正這種機器就是要壓榨整台機器的效能,所以不會拿小台機器出來給大家玩。這次推出的是 i3 系列,叫做 i3.metal

Today we are launching a public preview the i3.metal instance, the first in a series of EC2 instances that offer the best of both worlds, allowing the operating system to run directly on the underlying hardware while still providing access to all of the benefits of the cloud. The instance gives you direct access to the processor and other hardware, and has the following specifications:

Processing – Two Intel Xeon E5-2686 v4 processors running at 2.3 GHz, with a total of 36 hyperthreaded cores (72 logical processors).
Memory – 512 GiB.
Storage – 15.2 terabytes of local, SSD-based NVMe storage.
Network – 25 Gbps of ENA-based enhanced networking.

走了十年總算走到這塊了... 不過應該花了不少時間解決各種安全性的問題,像是 network isolation 以及反刷韌體的問題 XD

ElastiCache 支援 r4.* 了

每年 AWS re:Invent 要到的時候就會有很多新的消息出來,Amazon ElastiCache 的團隊應該也是配合著這一波放出消息:「Amazon ElastiCache Now Supports the R4 Node Family」。

包括了 memcachedRedis 都支援了:

Amazon ElastiCache now supports R4 node types. R4 nodes are optimized for latency sensitive and memory intensive workloads. They come in six sizes, providing 12.3GiB to 407GiB of available in-memory capacity. By setting up a 15-shard cluster for Redis, you can scale up to 6.1TiB of in-memory capacity. For Memcached, you can set up a 20-node cluster to support up to 8.14 TiB in-memory workloads. Equipped with the Intel Broadwell processor, and improved networking, R4 node family offers superior performance over the popular R3 node family.

這兩個應用都是看記憶體吃飯的...

RDS (MySQL/MariaDB) 支援 t2、r4 以及 m4 的新機種

這個大家等好久了,尤其 MySQL 常遇到需要用記憶體換效能的情境:「Amazon RDS for MySQL and MariaDB Supports R4, T2 and M4 Instance Types」。

先前 t2 最大只能開到 t2.large (8GB RAM),對於需要大量記憶體運算的 SQL query,就有機會被 MySQL 使用 filesort 寫到硬碟裡面暫存了。這次支援這些 instance type,開發環境至少有選擇可以開到 t2.2xlarge (32GB RAM) 跟他拼。

r4 應該是正式環境期待已久的 instance type 了。r3 最大是 r3.8xlarge (244GB),跟 r4 最大的 r4.16xlarge (488GB) 剛好差了一倍。

m4 就比較微妙了,順便補上去的感覺... 不過應該還是會有應用會剛好用到。

不過還是期待前陣子出來的 c5,對於寫出很驚人的 SQL query,在 MySQL 內跑大量運算的應用會有幫助,就繼續等吧... :o