Fwiw, vMotion checks the cpu supported flags compatibility before migrating. Pretty sure cpu must be all of the same family to be clustered together for this purpose.
The original article just struck me as yet another company that doesn't know how to properly run applications in virtualized environments. Yes, if your hosting provider supports hot or cold migrations, you should be aware and develop accordingly. I do see this quite often, that still today, people are surprised that their VM is not always running on the same physical box at all times.
I think you're being overly harsh. Picloud is a super-awesome abstraction layer for running Python over AWS.
The problem they have is that they are trying to support arbitrary Python (which includes underlying libraries like LAPACK which depend on runtime CPU detection working correctly) and expecting code will work the same across identical instance types.
I think normal people would consider this a fair assumption, and in the event that AWS's advertised CPU capabilities were not broken for some instances, it would hold.
I don't think it's fair to say that they're ignorant of how virtualisation works. Disclaimer: I am a huge picloud fan and they have saved me a lot of time.
This has nothing to do with not running on the same physical box and more to do with some physical boxes are advertising incorrect instruction sets to the OS.
