Apparently whatever they use for web software can't cope with HN traffic, which is fitting the title perfectly.
$ curl -I harmful.cat-v.org
HTTP/1.1 200 OK
Content-Type: text/html
Server: rc-httpd
Connection: close
Edit:
Sorry my bad, `rc` appears to be part of Plan9 (see: http://webcache.googleusercontent.com/search?q=cache:Mc7xQBU... ).
Here's the cache link to rc-httpd which seems to be the thing that's buckling under the load:
http://webcache.googleusercontent.com/search?q=cache:3ahE0vd...
werc (the CMS for cat-v.org) is also written in rc shell. It's bigger and does more work than rc-httpd, but rc-httpd always seems to be the point of failure. I suspect it fails where I used awk to parse the HTTP headers; plan 9's awk is very slow.
What's amusingly ironic, considering the content of the site, is werc and rc-httpd perform well on Linux and only Linux. The two together have been used on Linux of course, OpenBSD, Mac OS X, and the 9front fork of Plan 9; Linux is the only one where they perform well. It seems Linux the only operating system optimized for shell script performance, and yes, I laugh every time I say "optimized for shell script performance!"
On 9front werc and rc-httpd perform a role beyond serving pages: they exercise the system, and have exposed some nasty bugs. They were first used when 9front had barely diverged from Bell Labs Plan 9. Back then the system could barely handle the load of a far less trafficked site than cat-v.org. It wasn't just rc-httpd, the whole system would go down when just a few pages were loaded at once! 9front has come far enough that it's serving cat-v.org today, but it still has some way to go. werc and rc-httpd also still have some way to go, today there was talk of making werc cache pages which would help a lot, and I plan to improve rc-httpd a bit too, but I'll only take it so far. I don't really think 9front would be improved by prioritizing shell script performance. :D I might try to write a web server in C, I think I could do it now, or there was mention of maybe porting Varnish, too. I've never looked at Varnish... might do that tonight.
Trailing thought: If I do write a web server, I don't think I'll take it as far as Tom Duff did. Tom Duff's httpd keeps all the web pages in the executable; changing a page means recompiling!
... and having written all that, can I say how much I HATE form cookie timeouts?
The site is served by a single plan 9 virtual machine hosted by myself and maintained by stanley lieber. Further website optimization is not particularly high on our to-do list. Anyone who wants to donate CDN services or front-end varnish machines is welcome to get in touch.
[1] http://werc.cat-v.org/ [2] http://doc.cat-v.org/plan_9/4th_edition/papers/rc [3] http://man.cat-v.org/9front/8/rc-httpd
For those wanting to see it today: http://web.archive.org/web/20140209235144/http://harmful.cat...
Articles on the front page receive roughly 700 page views per hour.
Obviously, depends very much on time of day, attractiveness of the title etc.
I can't image how you'd write a web server that couldn't cope with that low load (actually I can but not for a mostly static site like this).
Even if we consider that it would be an additional page view every 5 seconds, this is barely believable that this would put the server under a stress load.
Either this one is wildly more popular or maybe something else is going on as well.
[1]
The site has trouble because we have devoted our meager resources to other tasks. If someone wants to donate beefier servers I'd gladly replace the aging, asthmatic machines that comprise 9cloud.
It's been my experience, however, that people generally don't want to spend that thousand dollars.