Instagram 改善影片上架速度的方式

不是什麼魔法,其實是改產品面上的規格 (但是發表到 Instagram Engineering 上):「Video Upload Latency Improvements at Instagram」。

最原始的版本是所有的格式都轉完後才可以上架:

然後把規格改成最高畫質的版本轉完後就可以先上架:

The idea is, instead of blocking until all video versions are available, we can publish the video once the highest-quality video version is available.

然後是把影片切段上傳,所以傳一半就可以先處理一半,變成 pipeline 的概念,但增加程式的複雜度,以及被迫要調整影片品質的參數:

Segmented uploads reduce upload latency in many cases but come with a few tradeoffs. For instance, segmented uploads increase the complexity of the pipeline. There are some quality metrics that are only available per segment at transcode time, such as SSIM. These metrics are not helpful to us on a per segment basis. Therefore, we need to do a duration weighted average of the SSIM of all segments to come up with the SSIM of the whole video. Similarly, handling exceptions is more complex since there are more cases to handle.

另外有一種特例是上傳的影片本身就已經符合伺服器的規格,這樣的話可以直接放行 (不過這樣不會有 security concern 嗎...):

Another performance optimization we use to improve the upload latency and save CPU utilization is something we call a “passthrough” upload. In some cases, the media that is uploaded is already ready for playback on most devices.

都是想的出來而且會帶有 tradeoff 的方法,而不是完全正面的改善 :o

幫你的 iPhone 電話簿找到對應的頭像

前幾天看到的:「Announcing Vignette」,透過 social network 的資料,把本來電話簿裡面的 icon 更新:

透過 app store 的搜尋找不太到,我一開始用了「Vignette」搜不到,但用「Vignette Update」就可以。或者你可以透過他提供的連結直接開 app store:「Vignette – Update Contact Pics」。

這是一個 IAP 類的付費服務,搜尋是免費的,但如果要把資料更新回通訊錄,需要付 USD$4.99 (一次性),台灣帳號是付 TWD$170,應該是因為最近的稅務調整:

Vignette allows you to scan your contacts and see what it can find for free. If you wish to actually save these updates to your contact list, you must pay for a one-time in-app purchase. That purchase costs $4.99, is not a subscription, and is the only in-app purchase.

搜尋的範圍包括了 GravatarTwitterFacebookInstagram

Email is used for Gravatar
Twitter
Facebook
A custom network called Instagram

另外作者有提到這個 app 不傳資料到伺服器上,都是在自己的裝置上連到上面提到的 social network 尋找:

Privacy is paramount
All the processing is done on-device; this isn’t the sort of app where your contacts are uploaded en masse to some server, and out of your control.

所以速度不會太快,但對隱私比較好...

Facebook 員工爆料內部密碼存了明碼

Krebs on Security 這邊看到的:「Facebook Stored Hundreds of Millions of User Passwords in Plain Text for Years」,Facebook 官方的回應在「Keeping Passwords Secure」這邊。

幾個重點,第一個是範圍,目前已經有看到 2012 的資料都有在內:

The Facebook source said the investigation so far indicates between 200 million and 600 million Facebook users may have had their account passwords stored in plain text and searchable by more than 20,000 Facebook employees. The source said Facebook is still trying to determine how many passwords were exposed and for how long, but so far the inquiry has uncovered archives with plain text user passwords dating back to 2012.

另外的重點是這些資料已經被內部拿來大量搜尋 (喔喔):

My Facebook insider said access logs showed some 2,000 engineers or developers made approximately nine million internal queries for data elements that contained plain text user passwords.

另外是 Legal 與 PR 都已經啟動處理了,對外新聞稿會美化數字,降低傷害:

“The longer we go into this analysis the more comfortable the legal people [at Facebook] are going with the lower bounds” of affected users, the source said. “Right now they’re working on an effort to reduce that number even more by only counting things we have currently in our data warehouse.”

另外也會淡化後續的程序:

Renfro said the company planned to alert affected Facebook users, but that no password resets would be required.

去年的另外一則新聞可以交叉看:「Facebook’s security chief is leaving, and no one’s going to replace him」:

Instead of building out a dedicated security team, Facebook has dissolved it and is instead embedding security engineers within its other divisions. “We are not naming a new CSO, since earlier this year we embedded our security engineers, analysts, investigators, and other specialists in our product and engineering teams to better address the emerging security threats we face,” a Facebook spokesman said in an email. Facebook will “continue to evaluate what kind of structure works best” to protect users’ security, he said.

看起來又要再換一次密碼了... (還好已經習慣用 Password Manager,所以每個站都有不同密碼?)

喔對,另外補充一個概念,當他們說「我們沒有證據有人存取了...」的時候,比較正確的表達應該是「我們沒有稽核這塊... 所以沒有證據」。

幹掉 Twitter 的推薦功能

Update:官方的「Show the best Tweets first」設定已經更新了,理論上你關掉後就不會出現這些 spam:

以下是原來的文章。


Twitter 預設是照時間排序,但是在這幾年就加入了「你可能會感興趣的 blah blah blah」之類的官方 spam,或是把 like 的插進來。

先前要幹掉這些功能頗麻煩的,我是看到就按不喜歡,然後大概就會有幾個禮拜不會出現,然後過一陣子後又冒出來...

最近有人找到方法可以一勞永逸的幹掉這些功能,找資料看起來是從這篇開始的,有人發現只要 mute 一些關鍵字就可以把這些功能從 timeline 上幹掉:

我找資料發現這些字其實是出現在 data attribute 上:

然後就有人開始翻開始整理了:

目前看起來效果頗不錯啊,這樣連手機上都可以擋掉這些 spam,頗不賴 :o

Facebook 觀察 IPv6 的使用情況

Facebook 是在六年前啟用了 IPv6 服務,然後分析了現在各地區 IPv6 使用的情況:「How IPv6 deployment is growing in U.S. and other countries」,另外提供了統計系統的資料給大家查 (不過看起來只有二月以後的?):「Facebook IPv6」。

然後被提到台灣區的成長在這幾個月很快速,主要原因是中華電信的導入:

We are also seeing countries and regions with less mature internet infrastructure start to transition to IPv6. Although overall deployment is still low, recent growth in some places has been exponential. Taiwan, for example, has gone from less than 1 percent in February 2018 to more than 10 percent as of May 28, 2018. Taiwan's rapid growth directly corresponds to recent IPv6 initiatives by Chunghwa, Taiwan's largest ISP.

先前在 Twitter 上有提到中華在 www.ipv6.hinet.net 網站上的跑馬燈有公告關於 IPv6 的導入,所以到這個月月底,使用比率應該都還會有明顯的提昇:

因為 Windows 7 以上的系統直接 PPPoE 的應該都會拿到 IPv6 address,但如果是 IP 分享器的就不一定支援了,不然應該會更高...

另外行動網路的部份也陸陸續續在轉移了,像我的 blog 上可以看到有 emome-ip6.hinet.net 的訪客,而且 Google 搜尋也可以看到一些資訊了:「"emome-ip6.hinet.net" - Google 搜尋」。

關於我在 Twitter 上貼的連結... (像是 Retweet,或是透過 Nuzzle/Pocket 貼的連結)

tl;dr:我把 Twitter 當暫存區,把手機上看到的連結丟到 Twitter 後再用桌機打開來看,所以有很多連結我雖然轉發,但未必看過。

我習慣在通勤或是睡前刷一下手機,看一下各類媒體有什麼資訊 (參考「為什麼我還繼續用 RSS (Feed)」這邊,是我找「未知的來源」的一部分),但這麼一來會遇到幾個問題:

  • 時間很零散,或是不長,所以有些文章我會看標題就先找個地方丟出來。
  • 手機上的廣告阻擋機制不太好,桌機的阻擋機制強大許多。

前陣子有些朋友問到為什麼 Twitter 上會有些明顯跟我的意見不同的 tweet,原因就是這樣啦...

Twitter 推出 Full-archive search API

在先前的「Twitter 要推出 Premium API」這篇文章裡有提到 Twitter 打算在 Standard 與 Enterprise 兩個層級中間推出 Premium API,算是補產品線的概念,提供 Startup 有中間階段的服務可以使用。

而在昨天,Twitter 推出了 Full-archive search API:「Introducing the premium full-archive search endpoint」,從 Rate limit 就可以看出來對 Enterprise 不夠用,但對 Startup 應該有機會使用:

台灣用 Twitter 的量偏低,也許對專注在台灣的應用來說還好,但對國外的單位來說應該是多了不少變化可以玩...

Facebook 自己找人研究,Social Media 是否對人類有害 XDDD

之前看到「Hard Questions: Is Spending Time on Social Media Bad for Us?」這篇,一直不知道要怎麼吐槽... 然後看到 Twitter 上的這則 tweet XDDD

既視感太重了,找了一下其他行業對應的資料:

真的不知道怎麼吐槽 XDDD