In case you think this piece is more incoherent than usual, I should explain that you’re reading it as I write it. More on that when I finally write the final conclusion to the piece. If you’re looking at this in an RSS reader, and there’s about five million other earlier versions, I apologise. Your aggregator is doing something that I wasn’t expecting, and I think may be a little silly. As the old spammers used to say, “just hit delete!”
So the edge (which is to say, where you live: your home server, your cellphone even, whatever is closest to you on the Internet) seems to be getting more reachable than it was. But what about reliability? If you’ve ever run an important service on your home machine, you’ll know about the Vacation Effect. This is a mysterious force which causes the home computer that to handles your email to crash within hours of you leaving home for a three week vacation, causing you to have to advertise for burglars on Craigslist to break into your home and reboot it.
Even if you can imagine the hardware at your house to be somehow more reliable, there’s always your flakey Net connection, which is up and down like a sine wave’s drawers. Dynamic IPs dynamically change, cable modems reset every few minutes, DSLs are flippantly unplugged by backhoes and disgruntled CO engineers. How could you possible imagine you could run a reliable service on that?
So, as some of you might have guessed, I moved Oblomovka off its co-loc a few weeks ago when I started this series, and transferred the whole website to my Mac Mini (perversely running Ubuntu) that I have in my cupboard here at home. I haven’t heard anyone complain about its unavailabilty, but then again I haven’t invited comments. I’m pretty sure it’s been down a few times, and as its heaviest user, I know I haven’t been able to ping it on occasion.
But it hasn’t been a huge problem. Partly because I’m not really an essential service to anyone else. Oblomovka down? Oh well, I guess I only have a few hundred other blogs to search. Mostly, though, I think it’s down to my first major point:
- The return of polling. Google picks up that I’ve updated my blog within a few seconds of me hitting send (I think because I ping one of the major blog ping servers).
Judging from the last time I turned on logs, almost everybody reads this site from RSS readers. RSS readers don’t need any stinking five nines. If my server is down, they keep on knocking at the non-existant door until I come back up.
I used to think that this was a fantastically bad idea, because of course polling doesn’t scale. I wrote a piece for New Scientist in 2004 hinting that this could be a problem for RSS.
As we now know, I was right, and RSS collapsed as soon as blogs became popular, and brought down with it the rest of the Internet, which is why you’re reading this on an Olivetti typewriter operated by a spirit medium.
As it happens, RSS is as shonky as the rest of the Net, and just keeps on acting as though it should work. My server doesn’t die under the weight of constant pings. And when my server does die, my readers just have to wait until it’s back up. I just don’t need the reliability.
That’s lovely for me, but what about, say, Boing Boing, or some other super-popular blog where readers (and advertisers) might get really peeved if I disappeared?
Well, what we have there isn’t a reliability problem. It’s a scaling problem. You’re getting lots of hits? Then commercialise them and get off your damn home server, you dirty freeloader. Which brings me to my next point:
- Increasingly granular scalability. Good scalability scales down as well as up. Every Net engineer I know has ended abandoning complexity in scaling by collapsing everything into something that just works if you throw more servers or RAM at it, and still works if some of those servers and RAM fry at some future entropic point.
EC2 and other cloud services appear to be the natural extension of this upwards in an unbounded way. If I need better reliability and bandwidth for my users with a simply-scalable design, I can (ideally) just throw more EC2 servers at them.
The corollary to this is that if we design edge services well, if they overload the edge, we can throw them up into the cloud again. People can live with higher levels of unreliability than most of us (including the brave, anal, guardians of our system administration class) imagine is possible. The Net is proof of this. It’s shitty, but it’s good enough. And if we want it better, we can usually pay for the privilege.
What running services at the edge is, in effect, creating services that can scale down to the minimum required. And that in turn, allows those services to scale right up to where they need to be, should they need to be more reliable and with greater loads.
Now, smart readers may have spotted the problem here. I began this discussion because I was confused and worried that we hand over our most private data to companies like Google, and SixApart and Amazon, when really the safest place to keep private data is on your own machine. Am I now suggesting that if somehow it’s okay that your edge server is flakey, because, hey, you can always use Google, and SixApart and Amazon. Aren’t I contradicting myself?
Yes. NO. Hold on. There’s a real difference between holding your data yourself and passing it to others in the event of emergency or changed circumstance. It would be better to think of these cloud services not as where you keep your data, but as temporary caches for the edge. I have an encrypted backup stored somewhere out there. I’m confident that only I have access to that. I’m not sure what I’d do if my home system did go down, but in an ideal world, I’d just feed that backup my key, have it float into operation on an EC2 machine, and then point oblomovka’s DNS to itself. When I had time to get things back to normal at home, I’d evaporate that EC2 machine. Oh, sure, evil gnomes from DoubleClick or the NSA might have pickpocketed that image while it was running, but I would at least have some intimation that was happening (just as the cops might break into my house and feel my pants, but I’d have a hair on the window if I was truly that paranoid). And if what we were talking about was truly just a cache of my current state (like a memcache of the last time my server was around), then it would not expose much deep knowledge of your precious life.
Especially as the benefits of being on the edge grew. For instance, for those of you peering at this from your RSS feed or on the Website before 12:20AM PDT, you’ll have noticed that I’ve been typing this directly into my home server. The words appear almost one by one on the site, as I tweak and update it. I could do that with a remote server, but it’d be a pain: the proximity of the edge to where I am gives the me the low latency and the reactivity to do these things. I feel nearer to the Net when it works like this. It feels more like I thought the Net would be, and more like how I think it will be soon.
Reached this point at:2007-11-15T00:11-0800. Keeping the message at the top to give an idea of how this might have felt to watch being typed at the time. Still under construction for typos and grammar fixes.