Home » Posts tagged "server" (Page 2)

將找 Origin Server IP 位置自動化的 CloudFlair

Twitter 上看到 CloudFlair 這個工具,可以找被 Cloudflare 保護的網站,將尋找後面 Origin Server 的 IP address 的過程自動化:

這隻程式配合 Censys 的資料去找,而不是自己獨立掃整個 IPv4 address。

另外這隻程式也不保證掃的出來,像是透過 Cloudflare 去年十一月推出的新服務 Wrap,就不需要將 Port 80/443 對 Internet 公開 (參考「Cloudflare 推出的 Wrap 讓你不用在本地端開對外的 Port 80/443」)。

不過還是蠻好玩的工具啦 XDDD

ExpressVPN 在土耳其的 VPN server 被抄...

ExpressVPN 在土耳其的 VPN server 被抄,為了調查大使的刺殺案件:「VPN Server Seized to Investigate Russian Ambassador’s Assassination」。

A VPN server operated by ExpressVPN was seized by Turkish authorities to investigate the assassination of Andrei Karlov, the Russian Ambassador to Turkey. Authorities hoped to find more information on people who removed digital traces of the assassin, but the server in question held no logs.

ExpressVPN 官方的回覆在「ExpressVPN statement on Andrey Karlov investigation」,主要的部份是:

As we stated to Turkish authorities in January 2017, ExpressVPN does not and has never possessed any customer connection logs that would enable us to know which customer was using the specific IPs cited by the investigators. Furthermore, we were unable to see which customers accessed Gmail or Facebook during the time in question, as we do not keep activity logs. We believe that the investigators’ seizure and inspection of the VPN server in question confirmed these points.

至於是不是真的,就需要時間確認了...

原來 Oracle 與 Microsoft 裡的條款是這樣來的...

看到「That time Larry Ellison allegedly tried to have a professor fired for benchmarking Oracle」這篇文章的講古,想起很久前就有聽過 Microsoft 有這樣的條款 (禁止未經原廠同意公開 benchmark 結果),原來是 Oracle 在三十幾年前創出來的?而且這種條款還有專有名詞「DeWitt Clauses」,出自當初被搞的教授 David DeWitt...

Microsoft 的條款是這樣:

You may not disclose the results of any benchmark test … without Microsoft’s prior written approval

Oracle 的則是:

You may not disclose results of any Program benchmark tests without Oracle’s prior consent

IBM 的反而在 license 裡面直接允許:

Licensee may disclose the results of any benchmark test of the Program or its subcomponents to any third party provided that Licensee (A) publicly discloses the complete methodology used in the benchmark test (for example, hardware and software setup, installation procedure and configuration files), (B) performs Licensee’s benchmark testing running the Program in its Specified Operating Environment using the latest applicable updates, patches and fixes available for the Program from IBM or third parties that provide IBM products (“Third Parties”), and © follows any and all performance tuning and “best practices” guidance available in the Program’s documentation and on IBM’s support web sites for the Program…

AWS 提供 Windows 上的 Deep Learning AMI

有一些 Windows 上的東西就可以直接開起來跑了:「Announcing New AWS Deep Learning AMI for Microsoft Windows」。

目前支援 2012 R2 與 2016:

Amazon Web Services now offers an AWS Deep Learning AMI for Microsoft Windows Server 2012 R2 and 2016.

然後 driver 與常用的東西都包進去了:

The AMIs also include popular deep learning frameworks such as Apache MXNet, Caffe and Tensorflow, as well as packages that enable easy integration with AWS, including launch configuration tools and many popular AWS libraries and tools. The AMIs come prepackaged with Nvidia CUDA 9, cuDNN 7, and Nvidia 385.54 drivers, and contain the Anaconda platform (supports Python versions 2.7 and 3.5).

AWS 環境裡面提供 NTP Service 了 (Amazon Time Sync Service)

以前在 AWS 環境裡都要自己架設兩台可以連外的 NTP server,然後將內部機器指到這兩台上,現在可以用現成的了:「Keeping Time With Amazon Time Sync Service」。

服務放在 169.254.169.123

You can access the service via the link local 169.254.169.123 IP address. This means you don’t need to configure external internet access and the service can be securely accessed from within your private subnets.

然後也有提到 leap second 的解法,用的解法是 leap smearing:

Leap seconds are known to cause application errors and this can be a concern for many savvy developers and systems administrators. The 169.254.169.123 clock smooths out leap seconds some period of time (commonly called leap smearing) which makes it easy for your applications to deal with leap seconds.

先前 AWS 也有 leap time,但不包括 Amazon EC2 這些系統 (EC2 裡的時間是獨立的),不過還是可以看一下 AWS 處理 leap time 的方式,因為這次 NTP Service 就會拿去用了。

最近一次 leap time 是 2016 年底的「Look Before You Leap – December 31, 2016 Leap Second on AWS」,處理的方式跟 2015 年時的方法還是一樣:「Look Before You Leap – The Coming Leap Second and AWS (Updated)」。

類似於下圖左上角這張的變化:

然後全區開放,都可以用了:

This service is provided at no additional charge and is immediately available in all public AWS regions to all instances running in a VPC.

去電視廣告的服務又來了...

看到「Plex’s DVR now lets you skip the commercials… by removing them for you」這篇文章,介紹 Plex 要推出去電視廣告的服務...

維基百科上的介紹比較清楚:「Plex (software)」,主要有兩個元件組成,media server 與 player:

  • The Plex Media Server desktop application runs on Windows, macOS and Linux-compatibles including some types of NAS devices. The 'server' desktop application organizes video, audio and photos from your collections and from online services, enabling the players to access and stream the contents.
  • The media players. There are official clients available for mobile devices, smart TVs, and streaming boxes, a web app and Plex Home Theater (no longer maintained), as well as many third-party alternatives.

然後這次要推出的功能是直接在錄影的時候把廣告拿掉:

Plex confirmed it’s rolling out a new feature that will allow cord cutters to skip the commercials in the TV programs recorded using its software, making the company’s lower-cost solution to streaming live TV more compelling. Unlike other commercial-skip options, Plex’s option will remove commercials from recordings automatically.

這讓我有些印像... 當年 TiVo 也有類似的功能,不過文章裡有提到 TiVo 是提供 skip 而非直接拿掉:

The new feature works by locating the commercials in your recorded media. It then actually removes them before the media is stored in your library. That sounds like it could be even better than TiVo’s commercial skipping option, for example, because you don’t have to press a button to skip the ads — they’re being pulled out for you, proactively.

不過主要是認識了 Plex 這個軟體... 如果是電視兒童的話應該用的到 XD 台灣目前的電視節目好像看的比較少...

AWS 推出可以在 Red Hat Enterprise Linux 上跑 Microsoft SQL Server 的 AMI

自從 Microsoft SQL Server 宣佈可以在 Linux 上跑後 (參考「Microsoft SQL Server 出 Linux 版...」),就沒看到什麼 Linux 上跑 SQL Server 的消息了... 結果在這波 AWS 的活動上推出了 RHEL 上跑 SQL Server 的消息:「Amazon EC2 now offers SQL Server 2017 with Red Hat Enterprise Linux 7.4」。

SQL Server 2017 is now available for Amazon EC2 instances running Red Hat Enterprise Linux (RHEL) 7.4 as an Amazon Machine Image (AMI) from the AWS Marketplace. With this release, you can now launch RHEL instances on-demand using SQL Server 2017 Enterprise License Included AMIs without having to bring your own license. SQL Server 2017 on RHEL 7.4 AMI is available in all public AWS regions starting today.

這個消息看到的時候嚇了一跳...

PChome 24h 連線會慢的原因... (續篇)

上一篇「PChome 24h 連線會慢的原因...」寫到 DNS resolver 會倒在路邊,但沒寫會怎麼倒... 因為規格書上沒有寫當問不到要問的東西時要怎麼處理,所以每一家處理的方式都不太一樣。

我把對各 DNS resolver 查詢 100 次的結果放在 GitHub Gist 上:「Query 24h.pchome.com.tw」,大家都是回 SERVFAIL,只是時間不一樣 (最後一個 x.xxxx total 的部份表示實際秒數,wall clock)。

先看這次的主角好了,HiNet168.95.1.1168.95.192.1,同時也應該是 PChome 24h 服務使用人數最多的 DNS resolver。

這兩個 DNS resolver 在遇到問題時不會馬上回 SERVFAIL,加上業界有小道消息說中華自己改了不少 code,所以跟一般的 open source software 行為不太一樣。由於看不到 PChome 端的 DNS packet,所以只能就行為來猜... 應該是在第一輪都查不到後,會先 random sleep 一段時間,然後再去問一次,如果第二次還是失敗的話才回應 SERVFAIL

這個 random sleep 看起來可能是 10 秒,因為數據上看起來最長的時間就是這個了。

SEEDNet 的 139.175.1.1 以及 Google8.8.8.8 都沒這個問題,都會馬上回應 SERVFAIL

前陣子新出的 9.9.9.9 (參考「新的 DNS Resolver:9.9.9.9」) 則是有些特別的狀況,可以看到前面有三個 query 很慢 (第 2、3、5 三行),但後面的速度就正常了。可能是新加坡那邊有三台伺服器在服務 (目前我這邊測試的機器到 9.9.9.9 會到新加坡),在第一次遇到都沒有答案時會有特殊的演算法先確認,之後就會 cache 住?

所以各家 DNS resolver 反應都不太一樣,然後最大那家有問題 XD

24h.pchome.com.tw 慢一次,ecvip.pchome.com.tw 再慢一次,圖片的 a.ecimg.tw 再慢一次,一個頁面上多來幾個 domain 就會讓人受不了了 XD

其實我只要改成 8.8.8.8 或是改走 proxy.hinet.net 就可以解決啦,但還是寫下來吧 (抓頭)。

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