Ruby on Rails site with 10 million users?

How big could a Ruby on Rails site scale interests me.
Take 37signals who have just over 1 million users. Amazing products
but not mass market like myspace or youtube...
If someone released a site that got huge traffic and users, how big
could it go?
5 million users, 10 million, 20 million?

Keep watching www.revolutionhealth.com since that's where it's aiming to
go. Beyond seeing the success or failure of such a huge site, how would you
know?

--Greg

Most people will ignore this question, but I’ll answer it…

Don’t measure in users, measure in hits. How many hits do you expect to get in a day? A user does not just come to your site once… they do a lot of things while they are there. Adding AJAX can really raise that number.

Rails, like PHP, Java, .Net, etc can scale just fine. You just need to know how.

I've seen www.revolutionhealth.com on Techcrunch.
A really nice site.
I didn't quite understand "Beyond seeing the success or failure of
such a huge site, how would you
know?"

DT.

I've seen www.revolutionhealth.com on Techcrunch.
A really nice site.
I didn't quite understand "Beyond seeing the success or failure of
such a huge site, how would you know?"

We can talk about shared nothing, about scaling up and scaling out, about
strategies for scaling, about data centers and server farms, but there's
nothing like an actual, real-world site standing up to load or failing to
do so to give you an idea of whether some technology can scale. If it
stands up, the technology scaled. If it doesn't, the people responsible for
making it scaled didn't succeed and the reason they failed may or may not
be something inherent in the technology itself.

Basically, the strategies exist, it can be attempted, and there is reason
to believe that it can succeed. Beyond that... did eBay or Amazon know
they'd be able to stand up to the load a priori, or did they just put it
out there and optimize when they started having problems? I don't know, but
I doubt that Jeff Bezos would have said in 1994 that he was sure he could
build a site that scaled to what Amazon deals with today.

DT.

--Greg

Install RoR on every internet connected computer in the world, with as
many mogrels as each computer, can handle using all the web servers in
the world connected thought the greatest clustering software in the
world, backed by every supported database running in the world to
store your data.

That's how far RoR will scale. Now how far can you "afford" to scale?

Being sarcastic to some degree in case you didn't catch on to
that.... Point being "Try it and see. And optimize as you go along."