On of the biggest pains in the ass with web apps is not really the development, changing technologies nor extremely demanding customers. It's actually hosting - seems like the easiest thing yet it's something that, most of the times, you have only a very little control over. Of course you still can put the server in the office but if you have multiple locations you need pretty good connection to support it. I've written countless times about problems with hosting in Singapore - from crazy prices to the total lack of support and overselling of capacities. With pretty much the only "reasonable" hosting provider here (Frro) going down I found myself in the middle of yet another server migration. It seems easy but installation of around 10 servers can be quite daunting :-).
Luckily (I so hope this luckily is going to last at least some time), there's a new kid in town - Rack Space Cloud. There's been so much buzz around the clouds over the past year or so (Amazon, Google, Microsoft), but none of them was really useable for hosting of rails applications. Rackspace Cloud offers Cloud Servers - they're quite similar to Slice Host's slices, however, come with some "cloud" extras. I don't really understand the technicalities of the processor computing power sharing on the cloud and as (I would assume) they don't have that many customers yet I cannot say how it's going to affect the performance.
What's great about the cloud servers, however, is the flexibility of other resources together with hourly billing. And the prices are currently more than reasonable. For the cheapest set up - 256 RAM and 10GB will cost you 1.5c per hour + the band with 8c per incoming GB and 22c per outgoing GB. Most of my apps will rarely hit transfer of more than around 5GB so my total costs works out to around $12 - 13 per month. The same set up on Slice Host is even $20. But it's really not just a price comparison. One of the main strengths of the cloud is flexibility to resize the servers as you need - increase the resources during peak hours/days and shrink it back off peak. This could be nicely automated with the API for Cloud Server that is being developed. Personally, I have mostly used this flexibility to test and compare different configurations - mod_rails vs. Lighttpd, Postgresql per instance vs. shared, various Postgresql settings and all this with different memory sizes. This experimentation actually led to some surprising (for me) results.
Another great feature is back ups. They allow you to create new servers from the back up images. What it means is that I have images with my typical configurations (mod_rails, Lighttpd, Tomcat + Apache, database server, etc.) and when I need to add a new server I just choose the image I need and within a few minutes the server is ready with everything I need, and all I have to do is add the new IP to hosts and configure the DNS. As we manage over 50 different applications, this comes extremely handy - not just for adding new ones but also to keep the existing ones in sync.
No matter how great the initial set up, things will always go wrong so I was quite curious about the support. Rackspace has been know for their great customer service ("Fanatical Support"). As the control panel is very new (about 2 weeks) there are still some glitches, however, I found the live chat always available and ready to help. For the "bugs" in the control panel - the support seems to be automatically notified and fixes everything within minutes. How I wish this was the case with Singaporean hosting where my server can be down for hours without any response from support. Enough bitching. Over the years I've grown to be very skeptical about hosting (and internet) providers. They usually start great but as soon as I prepay for several months everything goes down. Let's hope this one's going to be different :-)