I work for a large ISP, and we are retiring/replacing quite a few 2013 era Netflix OCA caches, and I was offered one. Of course, I couldn't say no 😅
資料當然是被清過的：
I knew that Netflix had wiped them all in the decommissioning process, that they ran FreeBSD, that they were crammed full of drives, and that's about it.
討論裡面出現了之前在 Reddit 裡面負責這塊的 EM (engineer manager)，wting：
I was the EM for Reddit's Growth team around this time. I am responsible for / contributed to a few features like the current signup flow, AMP pages, push notifications, email digests, app download interstitials, etc.
然後他提到他當初拒絕實做其中一些 dark pattern，然後在經過 [0] 的事情後，他決定換團隊：
There was a new product lead who joined with many good ideas, but some of them were dark patterns that I heavily protested. After a few months of this, it was obvious that I was going to be reigned in or let go[0]; I immediately transferred to a different org.
其中 [0] 的部份是，公司把他 reporting line 改成到 product lead XDDD
0: They changed it so I would report to the product lead, which is odd for an EM to report into a product chain and the only instance within the company ever.
另外他也講了一個事情，就是強姦使用者是有用的，而且超級有用：
Now let me explain the other side of the story. 4 years later, Reddit's DAU, MAU, and revenue have all grown at ridiculous rates[1]. Yes, power users complain—and still continue using the site—but the casual user does not. These dark patterns have been normalized on other websites.
These practices are done because it works.
1: Many friends are startup founders and I've been at a few startups myself—a byproduct of being in the Bay Area—and Reddit's growth numbers are impressive. As a former employee, I am quite happy about my equity growth.
[–]edgan 1 point 2 months ago
It could br better, but it is far better than than Azure and GCP. Azure's old one was better than their new beta interface last I saw it. GCP has some interesting ideas, but the side bar centric design doesn't function well. It also tries to do too much, and is too JavaScript-y happy.
After analyzing millions of posts containing mainstream and alternative news shared on Twitter, Reddit and 4chan, Jeremy Blackburn, Ph.D., and collaborators found that alt-right communities within 4chan, an image-based discussion forum where users are anonymous, and Reddit, a social news aggregator where users vote up or down on posts, have a surprisingly large influence on Twitter.
"Based on our findings, these smaller, fringe communities on Reddit and 4chan serve as an incubation chamber for a lot of information," said Blackburn, assistant professor of computer science in the UAB College of Arts and Sciences. "The content and talking points are refined until they finally break free and make it to larger, more mainstream communities."
# build the static files and put them on the static server
`make -C /home/reddit/reddit static`
`rsync /home/reddit/reddit/static public:/var/www/`
# iterate through the app servers and update their copy
# of the code, restarting once done.
foreach $h (@hostlist) {
`git push $h:/home/reddit/reddit master`
`ssh $h make -C /home/reddit/reddit`
`ssh $h /bin/restart-reddit.sh`
}
The process for actually doing the deploy looked the same, but now the system did the work for you and told everyone what you were doing.
另外值得一提的是，因為他們不是自己架 IRC server 而是用外面第三方的伺服器，所以他們決定 IRC 只有單向告知的功能：
There was a lot of talk of systems that managed deploys from chat around this time, but since we used third party IRC servers we weren’t able to fully trust the chat room with production control and so it remained a one-way flow of information.
2012 時則是把機器列表放到 DNS 上，某種 service discovery 系統：
First, it fetched its list of hosts from DNS rather than keeping it hard-coded. This allowed us to update the list of hosts without having to remember to update the deploy tool as well — a rudimentary service discovery system.
Another small but important change was to always deploy a fixed version of the code. The previous version of the tool would update master on a given host, but what if master changed mid-deploy because someone accidentally pushed up code? By deploying a specific git revision instead of branch name, we ensured that the deploy got the same version everywhere in production.
What happens if a server is launched while a deploy is ongoing? We had to make sure each newly launched server checked in to get new code if present. What about servers going away mid-deploy? The tool had to be made smarter to detect when the server was gone legitimately rather than there being an issue with the deploy process itself that should be noisily alerted on.
2014 遇到機器數量太多，推一輪要一個小時而被迫要平行化處理：
Over time, the number of servers needed to serve peak traffic grew. This meant that deploys took longer and longer. At its worst, a normal deploy took close to an hour. This was not good.
2015 則是加上 deploy lock，避免同時間有兩個人在 deploy：
Engineers would ask for the deploy lock and either get it or get put in the queue. This helped keep order in deploys and let people relax a bit while waiting for the lock.
2017 的部份則是提到了伺服器的數量：
This new mechanism allows us to deploy to a lot more machines concurrently, and deploy timings are down to 7 minutes for around 800 servers despite the extra waiting for safety.
The amount of memory varies per implementation, but in the case of this implementation, we could count over 1 million IDs using just 12 kilobytes of space, which would be 0.15% of the original space usage!
維基百科上有說明當資料量在 109 這個等級時，用 1.5KB 的記憶體只有 2% 的誤差值：
The HyperLogLog algorithm is able to estimate cardinalities of > 109 with a typical error rate of 2%, using 1.5 kB of memory.
It has come to our attention that many websites such as Forbes and Wired are now requiring users to disable ad blockers to view content. Because Forbes requires users to do this and has then served malware to them we see this as a security risk to you our community. There are also sites such as Wall Street Journal that have implemented pay-walls which we were are also considering banning.
Decentralized Reddit using a DHT to store content and a blockchain to rank such content. Whitepaper with more details here: http://lucaa.org/docs/kudos.pdf
