Inter-Cloud Rock, Paper, Scissors: Service Brokers, Semantic Web or APIs?
A very interesting philosophical and market trajectory arms race is quietly ramping while the rest of the world tries to ping together how the Kindle will kill Cloud Computing and how Twitter already has.
As @Jamesurquhart and I spend our time exploring the longer term evolution of Cloud Computing, we end up in orbit around the notion of the Inter-Cloud (or Intercloud, or InterCloud)
Inter-Cloud represents one vision that describes how Clouds of many types will interoperate, federate and provide for workload portability as well as how those that provide these services and those that consume them, will interact. You can see an interesting summary of these issues here in a fellow colleague’s post titled: “From India to Intercloud”
In the broadest sense, Cloud is being positioned in the long term to allow for true utility. This means that at a 30,000 foot view, consumers should be able to declare their business and technology requirements for workloads or application needs and TAMO! (then a miracle occurs,) that workload or application presents itself operating somewhere that meets those needs backed up by some form of attestation by the provider. Ultimately, I’d like to see a common way of auditing and validating those attestations. Apropos for this discussion, I bring up the notion of an API 😉
This all seems like a deceptively simple scenario. Realistically, it represents a monstrous challenge in execution. To wit, in Reuven Cohen’s recent write-up (“The Inter-Cloud and the Cloud of Clouds“) he quotes Vint Cerf’s definition of the problem with the issues at hand:
“…each cloud is a system unto itself. There is no way to express the idea of exchanging information between distinct computing clouds because there is no way to express the idea of “another cloud.” Nor is there any way to describe the information that is to be exchanged. Moreover, if the information contained in one computing cloud is protected from access by any but authorized users, there is no way to express how that protection is provided and how information about it should be propagated to another cloud when the data is transferred.“
There’s a giant sucking sound coming from the Cloudosphere…
The market is essentially rotating around three ways of describing a solution to this problem:
- Consumers of service declare their requirements using some methodology for doing so (either directly to trusted and discrete service providers or) using an intermediary or “service broker.” In the case of the service broker, it’s their job to take these declarations of service definition (service contracts) and translate them across subscribing service providers who may each have their own proprietary interface. This is starting to heat up as we already have players emerging in this space and analyst groups are picking up interest (Yankee, Gartner)It would be much better if there were an open and standardized way of ensuring that all providers used the same common interface and way of providing attestation of service contract satisfaction/compliance, which leads to…
- There’s the notion of the “semantic” exchange of information between Clouds positioned by folks like Sir Tim Berners-Lee (in reference to Cerf’s quote above): “…by semantically linking data, we are able to create “the missing part of the vocabulary needed to interconnect computing clouds. The semantics of data and of the actions one can take on the data, and the vocabulary in which these actions are expressed appear to constitute the beginning of an inter-cloud computing language.” Capitalizing on Berners-Lee’s definition of the Semantic Web wherein “a vision of information that is understandable by computers, so that they can perform more of the tedious work involved in finding, sharing and combining information on the web,” we see how this approach would play well into the service broker model, also.
- We’ve seen a lot of noise around using one or more API’s — open or proprietary — that allow for individual Cloud operation, management, assurance and governance, however nuanced those functions may be. Open-sourced or not, and even with unifying management interfaces available such as libcloud, each Cloud vendor today sees its capability for management and streamlined operations as its first layer of competitive differentiation and individual API’s — even when abstracted through service brokers — are a way to move offerings forward whilst working toward open standards such as these.
Honestly, my bet is that this arms race will net out such that we’ll end up with some combination of all three.
This isn’t as simple-sounding as it started, especially when we throw in the definitional differences between workload portability and interoperability as alluded to by all three approaches.
Add packaging elements such as OVF and the problem starts expanding into a very complex multi-dimensional issue very quickly.
Workload portability using common packaging formats (such as OVF) can be leaned upon to show how providers might deal the “lock-in” argument (you can move from my competitor to me,) but true interoperability is the real challenge here.
Reuven said it very well: “...what the world needs is not yet another API to control the finer nuances of a physical or virtual infrastructure but instead a way for that infrastructure to communicate with other clouds around it regardless of what it is. The biggest hurdle to cloud interoperability appears to have very little to do with a willingness for cloud vendors to create open cloud API’s but instead the willingness to provide the ability for these clouds to effectively inter-operate with one another. More simply the capability to work along side other cloud platforms in an open way.”
Here’s how I see Inter-Cloud playing out: In the short term we’ll need the innovators to push with their own API’s, then the service brokers will abstract them on behalf of consumers in the mid-stream and ultimately we will arrive at a common, open and standardized way of solving the problem in the long term with a semantic capability that allows fluidity and agility in a consumer being able to take advantage of the model that works best for their particular needs.