The view from an Enterprise (so called private clouds) and the capability to extend to clouds provided by service providers (so called Cloudbursting) is a little different from the pure play internet-based clouds (so called public clouds) Let me take this view and define what an Enterprise Cloud Infrastructure backbone would be, without actually defining it !
- Elasticity – This, of course, is given. A cloud essentially is an elastic infrastructure
- Multi-tenancy – Naturally, somebody should be using the extra capacity. This functionality is usually at the SP (Cloud Service Provider) side. An enterprise can also have multi-tenancy when it offers cloud capability to it’s organizations – whether they are business units or functional units (like HR and finance)
- Abstraction- The level of functionality from IaaS (Infrastructure As A Service) to PaaS (Platform As A Service) to SaaS (Software As A Service)
- Federation – The span – whether it is inside one datacenter or across multiple datacenters of an enterprise or extends to an SP
- Extension of Security Context/Scope – If we assume spanning across Service Providers with compatible infrastructure and with existing relationships, then we are extending the security context – a pragmatic approach
- Spanning Ownership domains – The enterprise has ownership if it is inside it’s firewalls and the ownsersip boundary is crossed to a cloud owned by an SP
Let us define Cloud Bursting in context of the six traits. It is very easy – Elastic, multi-tenant at the SP side, extending the security domain and a different ownership domain.
Careful observers would note that this is missing two traits (mentioned below) that is near and dear to the likes of Amazon and Azure. It is deliberate that I did not include them in the essential traits. While Enterprises can (and will) use public clouds for many projects, for the near future public clouds will not be a *native* part of an Enterprise Cloud Infrastructure backbone …
- Raw Internet – I do not think “raw” Internet is an essential trait of Enterprise Clouds. Meaning, the communication between the Enterprise and the SP would be via some form of overlay (or leased line or similar mechanisms) that has security, QoS, policy and other characteristics
- Pay-per-usage – I do not think an Enterprise Cloud Infrastructure backbone would be pay-per-use.