Tag Archives: time

Amazon ECS 可以跑 cron job 了...

在 Amazon ECS 上面固定時間跑某些東西,以前得自己用 AWS Lambda 帶 (或是自己架,不過這樣就要自己考慮 High Availability 架構了),現在則是直接支援:「Amazon ECS Now Supports Time and Event-Based Task Scheduling」。 Previously, you could start and stop Amazon ECS tasks manually, but running tasks on a schedule required writing and integrating an … Continue reading

Posted in AWS, Cloud, Computer, Murmuring, Network | Tagged , , , , , , , , , , , , | Leave a comment

微軟的 Time Service 回應錯誤的時間...

看起來會有不少災情 (像是 SQL Server 遇到使用 server side 的時間的 SQL query):「Windows Time Service is sending out wrong times and that’s a big problem」,報導裡引用了 Reddit 上「PSA: time.windows.com NTP server seems to be sending out wrong time」這邊的討論串。 為了避免這種情況,不同單位會用不同方法解決。像是財力充足的 Google 就自己搞了原子鐘,然後還放 Google Public NTP … Continue reading

Posted in Computer, Hardware, Murmuring, Network, Science | Tagged , , , , , , , , , | 1 Comment

Amazon EC2 上的 gettimeofday 與 clock_gettime 的效能

看到「Two frequently used system calls are ~77% slower on AWS EC2」這篇在講 gettimeofday 與 clock_gettime 的效能,另外搜資料時發現應該也是作者提問的「gettimeofday() not using vDSO?」這篇。 在 EC2 比較新的機器上用 tsc 應該是沒問題的 (在 2015 的時候官方就這樣建議了): it seems tsc support in Xen has improved with version 4.0 and with improved … Continue reading

Posted in AWS, Cloud, Computer, Hardware, Linux, Murmuring, Network, OS, Software | Tagged , , , , , , , , , , , , , | Leave a comment

DynamoDB 推出 TTL 功能

DynamoDB 推出了依照時間自動刪除的功能:「New – Manage DynamoDB Items Using Time to Live (TTL)」。 You can enable this feature on a table-by-table basis, specifying an item attribute that contains the expiration time for the item. 這個功能比較特別的是,刪除的 scan 是不收取費用的: There is no charge for … Continue reading

Posted in AWS, Cloud, Computer, Database, Murmuring, Network, Programming, Software | Tagged , , , , , , , , , | Leave a comment

Cloudflare 因為閏秒炸掉...

Cloudflare 這次閏秒炸掉:「How and why the leap second affected Cloudflare DNS」,影響範圍包括了 DNS query 與 HTTP request: At peak approximately 0.2% of DNS queries to Cloudflare were affected and less than 1% of all HTTP requests to Cloudflare encountered an error. 主要的原因在於 … Continue reading

Posted in CDN, Cloud, Computer, DNS, Murmuring, Network, Programming, Software, WWW | Tagged , , , , , , , , , | Leave a comment

Google 的 time.google.com

看到這張圖在講不同 server (service) 如何處理今年的 leap second (UTC 的跨年,台灣時間早上八點),出自 leap smear 這邊: 在很早前就有 time.google.com 這個 domain,但是當時 Google 的人有跳出來說明這個服務不是公開服務 (當時),不保證這個服務的正確性與穩定性:「timeX.google.com provide non standard time」。 不過一個月前公佈出來的 Google Public NTP 服務算是把整個系統搞定了。 其中在 Configuring Clients 這邊直接推薦用 iburst 參數,不愧是家大業大的 Google XDDD: When the server is unreachable … Continue reading

Posted in Cloud, Computer, Murmuring, Network | Tagged , , , , , , , , | 1 Comment

把 CSC (卡片背面的三碼) 變成 OTP (動態密碼)

把信用卡背面的後三碼 (Card security code) 變成動態密碼,雖然一般只會有三碼,但對於網路消費應該會有不少幫助,不過這樣就不能完全不拿出卡片了...:「This high-tech card is being rolled out by French banks to eliminate fraud」。 產品叫做 MotionCode,會先從法國開始: Today both Société Générale and Groupe BPCE, two of France’s largest banking groups, are preparing to roll out these cards across … Continue reading

Posted in Computer, Financial, Hardware, Murmuring, Network, Security, WWW | Tagged , , , , , , , , , , , | 1 Comment

密碼系統的 Monoculture

這篇文章講到最近密碼系統的現象:「On the Impending Crypto Monoculture」。 目前常在用的密碼系統包括了 RSA、DH、ECDH、ECDSA、SHA-2、AES 這些演算法,而最近這幾年大家在推廣使用的演算法都出自於同一個人手裡,Dan Bernstein,也就是 djb: A major feature of these changes includes the dropping of traditional encryption algorithms and mechanisms like RSA, DH, ECDH/ECDSA, SHA-2, and AES, for a completely different set of mechanisms, including … Continue reading

Posted in Computer, Murmuring, Security | Tagged , , , , , , , , , , , , , , , , , , , , , , , , , , , | 1 Comment

加州在規劃廢除日光節約時間

加州在規劃廢除日光節約時間:「California could drop Daylight Saving Time」。 A California lawmaker has introduced a bill to unshackle the Golden State from the horological chains of Daylight Saving Time. 主要是沒有實質效益,甚至是與當初預期的反效果: Daylight saving time is observed in about 70 countries worldwide, but its benefits … Continue reading

Posted in Financial, Murmuring, Political, Science, Social | Tagged , , , , | Leave a comment