Netflix has moved its video-on-demand streaming service to the cloud, taking its datacenter to Amazon Web Services EC2 (AWC), citing the need for agility and the high cost of running Oracle on IBM as its primary motive.

Adrian Cockcroft, Cloud Architect at Netflix, said in an interview with Cloud Innovators: Business agility and the inability to predict how much capacity we would need when and where for a business whose growth is accelerating. Year on year customer growth is 52% (up from 42% last quarter), year on year customers using streaming is up 145% (from 4M to 11M). We need to be a small-ish fish in a big AWS pond to leverage AWS investment in datacenter build-out, rather than building our own pond.

The key processes Netflix is moving to AWC includes encoding movies for streaming, log analysis, production web site and API, most everything that scales with customers and streaming usage.

Other reasons cited by Netflix were the higher costs of setting up its own datacenter and the speed at which they were able to create a datacenter in cloud. Cockcroft stated that Netflix was able to add 4 to 5 times the number of datacenters it had in the last year.

The rationale behind Netflix's choice of AWS public-cloud over private-cloud was based on the fact that private cloud cannot beat public cloud in price. Cockcroft stated: I don't believe private clouds can compete with public on price, however if you have a bunch of empty datacenter space or want to re-organize your internal systems to be automated and API driven then there are real cost savings to building your own private cloud.

He also said that VMware and Microsoft will rule the private cloud segment while Amazon will rule the roost in public cloud.

He also called Zynga's success as an example to drive the point as to how small companies can leverage on public-clouds to become successful.

However, Cockcroft also added a word of advice saying that the companies who wish to move to the cloud should be aware that the hardware and underlying services are ephemeral, unreliable and may be broken or unavailable at any point, and that the other tenants in the multi-tenant public cloud will add random congestion and variance.

He said that scale related problems will continue to plague even with best of the hardware and that architects should take the patterns you have to use at large scale, and using them at a smaller scale to leverage the lowest cost infrastructure.