Amazon Web Services today introduced a new pricing model for its EC2 compute-on-demand service, offering customers the ability to reserve large amounts of capacity for future use. The feature, known as Reserved Instances, is the latest in a series of steps by Amazon to make AWS more attractive to enterprise users. In introducing the new pricing, Amazon cloud evangelist Jeff Barr highlighted a particular use case.
"Quite a few customers actually told us ... they were interested in using EC2 but needed to make sure that we would have a substantial number of instances available to them at any time in order for them to use EC2 in a DR (Disaster Recovery) scenario," Jeff writes. "In a scenario like this, you can't simply hope that your facility has sufficient capacity to accommodate your spot needs; you need to secure a firm resource commitment ahead of time."
This is an interesting pitch, with implications for Amazon's data center infrastructure. Here's why:
If the Reserved Instances offering is widely used, Amazon will have to ensure that it has the data center space and servers on standby. In the event of a major disaster along the lines of 9-11, Amazon must instantly deliver every bit of EC2 capacity that it has promized to customers. Pre-selling the capacity effectively allows Amazon to monetize the data center infrastructure before it's ever used. It's the virtual equivalent of a build-to-suit data center in which multiple anchor tenants reserve their space with a credit card.
How will Amazon certify for enterprise customers that the capacity exists? It seems unlikely that Amazon would indulge in the hosting industry's bad habit of overselling (taking orders for resources you don't possess and can't guarantee). But I would also have said that about Yahoo, which is now offering unlimited hosting accounts.
Amazon says very little in public about its data center infrastructure. We gather it will be sharing more information with enterprise prospects before they will bet their entire business on the ability to fire up their infrastructure on EC2.
And make no mistake: disaster recovery is about placing your business in the hands of a third-party provider. Confidence in a provider's reliability is paramount. Amazon's pitch for disaster recovery business suggests growing confidence that businesses are ready to step further onto the cloud with their most mission-critical apps. But for customers, the "show me" factor will loom large.