Microsoft has quietly released the November 2010 SDK, without being accompanied the fanfare at it’s PDC launch. One of the big changes to Windows Azure is the VM Role which allows you to upload and run a Windows Server VHD. Although it smells like IaaS, it is not – as described by Microsoft’s Steve Plank,
The way to look at the VM Role is that the entire thing is a Windows Azure application. You don’t send a .cspkg file, but instead, the package is a .vhd file. Now, because these files are likely to be huge in comparison to a .cscfg, Windows Azure has created a method of updating with differencing disks, but that’s just an implementation detail. You can think of a VM Role application package as the .vhd file.
One of the best features about Windows Azure is (was?) that it implemented a PaaS model and forced you to build systems that were architected for the cloud from the ground up. Legacy doesn’t scale and Windows Azure made it difficult to lift and shift legacy apps, while at the same time allowing for a lot of re-use of existing code, skills and even, with SQL Azure, data access and storage.
The VM Role was probably quite easy to implement, after all, web and worker roles are VM’s anyway and was done, apparently, in response to demands from customers. I question whether or not those customers actually understood what they were asking for and now have the option, not just to lift and shift legacy applications, but to build legacy applications from scratch – and that is a problem for cloud computing.
AWS, on the other hand, is unashamedly IaaS and seems to have created an environment for cloud architectures to flourish with all the cloud frameworks that people are enthusiastically building on top of AWS. I don’t think Windows Azure will be able to pull the same stunt – after all you can’t run a Linux instance in the same datacentre as your Azure application.
With the VM role Windows Azure hasn’t built a good IaaS offering, they have taken a good PaaS offering and injected confusion, removed their product differentiation, encouraged bad architectures and corrupted the fundamental DNA of their PaaS offering. Microsoft is really battling to sell Windows Azure and convince people to use the platform – the VM role may seem to be good in the short term, but it does break the product.
Simon Munro
Cloud Comments .net 