Many businesses fail to save significant amounts of money when they migrate to cloud IaaS, because of the cost of their software stacks. This can happen in a myriad of ways, such as:

• Getting on-demand hardware by the hour, but having to pay for permanent, peak-load software licenses
• Paying an “enterprise” uplift on software licenses or running into other licensing-under-virtualization issues
• Spending money on commercial middleware when free open source will do

While there obviously a host of complex issues surrounding software licensing both with in-house virtualization and in the external cloud, I want to focus this blog post on this last point: Using a big complex heavyweight package when a lighterweight simpler one will do.

In the enterprise, especially pre-virtualization, it previously made a reasonable amount of sense to standardize on relatively heavyweight architectures — say, WebLogic or WebSphere on top of an Oracle database. Sure, there were some applications that actually used the full power of Java EE and needed fancy Oracle features (like RAC), but for the most part, the zillions of apps within enterprises are basically business process, workflow, paperwork apps — fill out a form, take some kind of minor action, run a report. They work fine and probably unchanged, on a sliver of a compute core, JBoss, and MySQL, for instance. (And, while we’re at it, run fine under Linux rather than a proprietary Unix flavor.)

I used to convince Web hosting customers that they ought to switch from Solaris to Linux in order to save money. (I still occasionally do, though Solaris is a vanishingly tiny percentage of the market these days, going from near complete market dominance to being essentially negligible in less than a decade and a half.) These days, I pitch clients on why they should consider converting to open source middleware if they’re going to the cloud and want to maximize their cost savings.

The fact of the matter is, it’s expensive to shoot sparrows with a cannon. Standardizing on a single platform has cost advantages right up until the time that the single platform is vastly more expensive than having two platforms. Most of the compute infrastructure in most enterprises is used for commodity applications, and it makes sense to bring down the operational cost of those applications as much as possible. Open source does not necessarily mean free, of course, and commercial open source can be plagued by the same sorts of licensing issues, but there are good things to explore here (and even if open source doesn’t cut it for you, exploring commercial alternatives that are more cloud/virtualization-friendly is still a boon).

Gartner clients: I’ve written about this topic before, in “Open Source in Web Hosting, 2008“. My colleague Stewart Buchanan has authored a magnificent series of notes on this topic, and I recommend you read, at the very least, “Splitting End-User and Service Provider Licensing Will Increase the Costs and Risks of Virtualization and Cloud Strategies“, as well as “Q&A: How to License Software Under Virtualization“.