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

EC2 的 X1e 推出更小台的機種

本來 EC2x1e 家族只有 x1e.32xlarge,現在拆小拿出來租了:「Amazon EC2 Update – X1e Instances in Five More Sizes and a Stronger SLA」。

這次算是補足中間的缺口,因為先前的洞有點大:r4.16xlarge 是 488GB RAM,而往上就變成 x1e.32xlarge 的 3904GB,中間都沒有其他選擇可以用。這次 x1e.8xlarge (976GB) 與 x1e.16xlarge (1952GB) 算是補上了這邊的缺口,拿來跑需要大量記憶體,但還不需要到 4TB RAM 等級的程式...

Amazon EC2 的 CRI 支援一年版本了...

Amazon EC2 的 CRI (Convertible Reserved Instance) 支援一年的合約了:「EC2 Convertible Reserved Instance Update – New 1-Year CRI, Merges & Splits」,這樣彈性再多了一些:

Today we are introducing Convertible RIs with a 1-year term, complementing the existing 3-year term.

不過 CRI 主要是用在需要換 family type 的情境下,如果是已知 family type (像是一般性的 worker 會選 C4 或是剛推出的 C5) 那麼就直接選擇 Regional RI 就好...

基本上就是讓財務操作上多個選擇 :o

Amazon EC2 推出新的 GPU 系列機器

這次 Amazon EC2 推出了 G3 instance:「New – Next-Generation GPU-Powered EC2 Instances (G3)」。

這次開放的只有這幾區,亞洲目前還沒有在內:

You can launch these instances today in the US East (Ohio), US East (Northern Virginia), US West (Oregon), US West (Northern California), AWS GovCloud (US), and EU (Ireland) Regions as On-Demand, Reserved Instances, Spot Instances, and Dedicated Hosts, with more Regions coming soon.

這次使用的 GPU 是 Nvidia 的 Tesla M60:

Today we are taking a step forward and launching the G3 instance type. Powered by NVIDIA Tesla M60 GPUs, these instances are available in three sizes (all VPC-only and EBS-only)[.]

G3 (M60) 應該會比 G2 (K520) 快,但未必會比 P2 (K80) 快,尤其是 double precision 的部份,可以參考「Nvidia Tesla」這邊的數據。所以還是得看應用程式才能決定要用 G3 還是 P2...

MongoDB 的 Index 種類

Percona 的人寫了一篇簡單的文章介紹 MongoDB 的 Index:「MongoDB Indexing Types: How, When and Where Should They Be Used?」。

官方文件的「Indexes」算清楚,不過有些地雷沒講,像是 Unique Indexes 只這樣說:

The unique property for an index causes MongoDB to reject duplicate values for the indexed field. Other than the unique constraint, unique indexes are functionally interchangeable with other MongoDB indexes.

但 Percona 的人就有說出「地雷」,算是不錯的補充教材 XDDD

Unique indexes work as in relational databases. They guarantee that the value doesn’t repeat and raise an error when we try to insert a duplicated value. Unique doesn’t work across shards.

話說前陣子聽到傳言抱怨,MongoDB 的文件是行銷 & 團隊寫出來的,一堆限制都沒寫在明顯的地方... XD

ScyllaDB 1.7 支援 Counters 了

在「Scylla release: version 1.7」這邊看到 ScyllaDB 支援 Counters 的消息了 (雖然剛出來,掛著 Experimental 的消息):

Scylla now supports Counters as a native type. A counter column is a column whose value is a 64-bit signed integer and on which two operations are supported: incrementing and decrementing.

這其實是 Cassandra 其中一個強項,針對 counter 這種應用特化的資料型態。