Organizations are utilizing the cloud in growing numbers, but given the recent news about cloud outages first with Amazon AWS, then at Google Blogger and most recently with Microsoft BPOS some organizations are rethinking their strategy and trying to decide how to choose a cloud service model that works best for them. See this article in the NYT for example: Amazon’s Trouble Raises Cloud Computing Doubts.
There is no doubt that the Cloud works for many use cases, however not all cloud is the same. There are different considerations for different applications and choosing the right cloud model is critical to the business. If you are thinking about which cloud model is right for you there are a few things to consider. The primary consideration is whether to go with public or private cloud.
When to use the Public Cloud
With public cloud compute resources are shared and they are accessed over the internet at best effort. When choosing to get services from the public cloud you would consider if regulations concerning data protection will allow it, and if it fits with your corporate goals for availability and recovery. This last concern might be the key deciding factor in cloud service adoption.
Any business that is looking to outsource their IT infrastructure to the cloud must consider the whole of their business before taking the plunge. There is a benefit in having access to resources that are elastic and available on demand. The public cloud can work well for batch work, seasonal, periodic, one-time and some public facing uses cases.
Kevin McEntee, Vice President of Systems Engineering at Netflix explained how they use the public cloud for consumer facing transactions at the recent Cloud Connect event, see Cloud Connect Keynote: Complexity and Freedom. However Netflix still maintain their back office systems in house.