IaaS, SaaS, PaaS: Too Many Choices - Which Is Best for You
Dick Benton, principle consultant at GlassHouse Technologies, has written a 2 part article on the trials and tribulations of which Cloud to use entitled; “Cloud Thunder: The Biggest Bang for the Buck, Part 1”. I thought we would deal with the first part, IaaS, and examine his analysis of INTERNAL versus EXTERNAL Infrastructure as a Service (“IaaS”). His article has a bit for everyone, the IT manager, the Finance department, and the contract draftsman. As you all know, I get a little “weak in the knees” with the technical stuff and so I will defer to the techies on those issues. But Benton has some good insight on which “Cloud” to choose and solid advice on how to get there.
Benton starts off by commiserating with the IT Manager because the virtualized world of Cloud Computing does offer many alternatives to reduce cost while at the same time increasing service. He breaks down his discussion in part 1 on IaaS to the benefits and possible disadvantages of Internal IaaS as opposed to External IaaS.
In order to chose the Internal IaaS model, Benton notes that the x86 platform must be virtualized and ITIL (“Information Technology infrastructure Library”) service model has been adopted (See: “weak in the knees” comment above). I’ll leave the previous comment for the techies to determine. The benefits of the Internal IaaS model are:
· Availability
· Performance
· Security
· Quick provisioning
· Just as Quick De-provisioning
· Ease of billing to identify unit cost (Giga-bytes of storage or Giga-hertz of power)
· Automation improves Service Levels
With IaaS comes ITIL best practices which require automated self-provisioning. For the finance department the billing should have the ability to determine unit costs. And with all the above benefits, Benton still stresses that, “The biggest impediment to the introduction of IaaS under IT is that the service provider is the requirement for some form of portal/Web-based self-provisioning capability.”
Outsourcing IaaS (i.e. External IaaS) has its distinct advantages as well. But, of course, as we have discussed in the past security remains the paramount disadvantage. Your data is stored off-site and the infrastructure is shared with many other entities and dynamically managed as your data is moved from server to server. Benton points out three other necessary issues to consider:
· Back-out strategy. If your provider does not live up to the service levels promised, how do you get your data back?
· Scalability. Is this built into your contract? Premiums charged and can the Provider deliver in your time frame?
· Hybrid approach. Useful when using Internal IaaS and there is extra capacity needed in an overload situation for a special project.
Benton discusses SaaS and PaaS in the second part of his article.