Home » 2017 » April (Page 3)

Amazon DynamoDB Accelerator (DAX)

DynamoDB 推出的新架構,在系統上幫忙處理 cache:「Amazon DynamoDB Accelerator (DAX) – In-Memory Caching for Read-Intensive Workloads」。

DAX 跟現有的 DynamoDB API 相容:

DAX is a fully managed caching service that sits (logically) in front of your DynamoDB tables. It operates in write-through mode, and is API-compatible with DynamoDB.

因為 cache 的緣故,會是 eventually-consistent 架構:

Responses are returned from the cache in microseconds, making DAX a great fit for eventually-consistent read-intensive workloads.

然後是 r3 系列的機器組成的,限制在十台 (冒出大大的問號):

Each DAX cluster can contain 1 to 10 nodes; you can add nodes in order to increase overall read throughput. The cache size (also known as the working set) is based on the node size (dax.r3.large to dax.r3.8xlarge) that you choose when you create the cluster. Clusters run within a VPC, with nodes spread across Availability Zones.

不是很清楚這樣的好處 (比起自己用 memcached 或是其他類似的 cache 架構),也許過幾天想通了會開竅... :o

Cloudflare 推出 SSL 的 SaaS 服務

Cloudflare 把之前需要人力介入的操作,包成 API 直接提供給大家用:「Introducing SSL for SaaS」。

要解決的是「用戶自己的 domain 掛到我的服務上,而且需要 HTTPS」,而 Cloudflare 提供 API 把上面三部跑完,下面的就是 Cloudflare 自己處理 (包括取得用戶的同意):

如何讓工程師一個禮拜工作 60~80 小時

從「How do you make programmers work 60-80 hours per week?」這邊看到的,出自 Quora 的「How do you make programmers work 60-80 hours per week?」。

看到標題的時候在想「這什麼詐騙集團類型問題 XDDD」,寫 code 的工程師一天可以專注三個小時就很了不起了好嗎,然後年紀愈大就愈難專注。每天可以工作十小時鐵定是一堆時間在看 YouTubeFacebookTwitter 的好嗎 XDDD

仔細看了文章以後,發現其實作者就是在講這個:

No programmers really work 60-80 hours a week, especially in a 5 day span. That is a 12-16 hour day, 5 days a week.

I promise you that any company that has programmers “working” that many hours is really only getting 2-4 hours of real work out of them each day. The rest of the time will be filled with pointless meetings, a fair amount of web browsing, and then a whole lot of looking busy.

真的有寫程式都知道的啦...

新墨西哥州禁止因為學童付不起營養午餐,就要求他們以勞力付出

禁止這類變相的羞辱行為:「New Mexico Outlaws School ‘Lunch Shaming’」。

In some schools, children are forced to clean cafeteria tables in front of their peers to pay the debt. Other schools require cafeteria workers to take a child’s hot food and throw it in the trash if he doesn’t have the money to pay for it.

法案包括了所有有接受補助的學校:

On Thursday, Gov. Susana Martinez signed the Hunger-Free Students’ Bill of Rights, which directs schools to work with parents to pay their debts or sign up for federal meal assistance and puts an end to practices meant to embarrass children. It applies to public, private and religious schools that receive federal subsidies for students’ breakfasts and lunches.

利用 Side-channel 資訊判斷被 HTTPS 保護的 Netflix 影片資訊

在「Netflix found to leak information on HTTPS-protected videos」這篇看到了研究員透過 VBR 所透露出的 side channel 資訊,成功的取得了被 HTTPS 保護的 Netflix 影片資訊。這對於美國的 ISP 是個大利多 (加上之前通過的法案),但對於個人隱私則是嚴重的打擊。

這項研究的準確率非常高:

To support our analysis, we created a fingerprint database comprised of 42,027 Netflix videos. Given this collection of fingerprints, we show that our system can differentiate between videos with greater than 99.99% accuracy. Moreover, when tested against 200 random 20-minute video streams, our system identified 99.5% of the videos with the majority of the identifications occurring less than two and a half minutes into the video stream.

而且他們居然是用這樣的單機分析:

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苦啊...

Stripe 的 Increment 雜誌

Stripe 推出了 Increment 雜誌,講團隊合作時的各種議題:「Introducing Increment」。

And so we've decided to start Increment, a software engineering magazine dedicated to providing practical and useful insight into what effective teams are doing so that the rest of us can learn from them more quickly.

雜誌網站上也有類似的描述:

A digital magazine about how teams build and operate software systems at scale.

Increment is dedicated to covering how teams build and operate software systems at scale, one issue at a time.

可以看一看 Stripe 對團隊合作的想法...

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