For several years now we’ve become accustomed in medium and large environment to using the per-Processor licensing models. The main driver for this has been that in the Internet environment counting, let alone identifying, our end users has become almost impossible so being able to assign each of them a per-User licence has become almost impossible.
In the SQL Server world the per-Processor model gave us an “all you can eat” option whereby as long as the physical CPUs were adequately licensed you could have as many CPU cores, as much server memory, or as many end users as you like, and well as various number of instances of SQL Server depending on your edition.
All you can eat
Per-processor licences are expensive, there’s no way of suggesting they’re not, but these days the amount of server resource we can use with a single processor licence is massive compared to what it was just 2 or 3 years ago; I regularly work with servers now with 24 or 32 logical CPUs and 64GB of memory and these are considered not quite but almost entry level servers. With Intel and AMD’s CPUs now coming with 6, 8 or 10 cores, plus Hyper-Threading, that’s quite a few logical CPUs.
Microsoft are different to some of their competitors in that they only require us to licence the physical sockets in use, whereas other database vendors are interested in the number of cores that are in use too, often pushing the licensing price up a lot.
VMware’s new licensing model
VMware, the virtualisation software company, probably has its software deployed on servers near to or equally as large as SQL Server does, and almost certainly in greater numbers. As a result their software previously did have CPU core limits, although to be fair the server hardware at the time meant these limits weren’t often reached.
In recent weeks VMware have released version 5 of their premier virtualisation platform vSphere. Along with a range of new features for medium and large enterprises they’re also released a new licensing model. Now not only is the CPU resource a licence constrained commodity but so is memory.
VMware have introduced the concept of vRAM, a total amount of memory which can be assigned to virtual machines at any point in time. Now as you buy more licences not only does the number of CPU cores you can use increase but so does the amount of memory you can use.
The future of licensing?
For now, VMware’s licensing model change is being seen as “bad” because it’s different, and will mean users will have to potentially pay more money to use the server hardware they’ve only just installed vSphere 4.1 on. There was a similar response when SQL Server 2008 R2 Enterprise Edition dropped support for an unlimited number of virtualised instances. Was that the first time we saw the beginning of Microsoft’s reaction to “all you can eat” licensing on modern server hardware?
The reality is from the vendor’s perspective something has to be done to maintain their revenues as server capabilities increase at the rate they have done in recent years. Microsoft have obviously been able to afford to offer an “all you can eat” per-Processor model albeit with a change in the definition of unlimited, but it will be interesting to see how the next generation of on-premise licensing models adapt to the multi-core multi-GB memory servers that we’re regularly deploying today.
For more information on the recent changes to the VMware licensing model please see the link here.