@fuzzyfungus wrote:
You can't literally open-source your way into a big pile of distributed infrastructure for almost no money; but that does bring up an arguably very important distinction: some flavors of 'cloud' have multiple vendors, or at least a second-source. Something like basic LAMP or Windows/MSSQL web hosting is commodified pretty hard. Something like Amazon's suite of offerings is a bit less interchangeable(though many useful subsets of it are). This doesn't save you if you go with a single vendor, and that vendor goes down; but (as you correctly note) reliability is easier and cheaper to achieve at scale, and since the vendors all have very limited market power, their ability to mess with you is limited.
Other 'cloud' stuff is, whether by reason of technical lock-in (without the crypto keys, even a protocol-compatible implementation of Xbox Live or Apple's App Store is dead in the water) or by virtue of a sprawling featureset with no fully compatible implementations.
Both are vulnerable to technical disruptions; but only the latter really offer the vendor dangerous amounts of leverage over you.