Licensing Microsoft’s SQL Server on Amazon Web Services (AWS) costs much more than it does on other cloud platforms, according to a customer who has researched the options.
A SQL Server licence typically costs more than the VM (Virtual Machine) on which it is hosted, so it is significant when evaluating cloud providers (presuming that your application requires Microsoft’s database server). James Crowley looked at three contenders: Amazon Web Services, Rackspace and Microsoft’s own Azure platform.
Of these, only Microsoft separates the cost of SQL Server from the total cost of the VM. However, you can calculate how much SQL Server costs by subtracting the price of a VM without SQL Server from the price when it is included. For example, an 8 core r3.2xlarge AWS VM is $1.080 per hour with Windows, or $2.775 per hour with Windows and SQL Server Standard, which means SQL Server costs $1.695 per hour (figures from here).
On Azure, adding SQL Server Standard to an eight-core VM invariably costs $0.80 per hour, so in this case AWS is more than twice as expensive.
Crowley says that Rackspace is consistently around 25 per cent more costly than Azure, and AWS from 70 per cent to 195 per cent pricier.
Incidentally, Crowley also notes that SQL Server on a physical machine tends to be better value, because Microsoft licenses its product per core, but ignores hyper-threaded cores. An Intel Xeon E7, for example, might have eight cores but support 16 concurrent threads. In a VM, this distinction is lost.
The question remains, though: why the big discrepancy? We asked both Microsoft and Amazon for comment and have yet to receive a response. It is worth nothing that on all three clouds customers have an option to license SQL Server themselves, through a feature called Microsoft License Mobility, which requires a volume licence supplemented by Software Assurance. With such a licence, though, you lose the ability to pay as you go, shutting down VMs when not required, one of the key benefits of cloud computing.
Software licensing is complex, so it is dangerous to reach quick conclusions about why there is such variance in pricing. That said, Microsoft may be happy that customers have a price incentive to use its Azure platform. It is also possible that Amazon does not mind if customers consider switching from SQL Server to, say, its own RDS (Relational Database Service) for Aurora, now in preview, which is much less expensive.
Advantage Microsoft, or advantage AWS? ®