I stumbled across a 2012 article on this [0] that says they'd 'retire' instances. Wouldn't force the VMs over to another host, they'd just terminate them. They'd generally give forewarning.
I wonder about live migration. I imagine there must be some brief interruption even there.
> Many VMs are run indefinitely, so whatever machine they’re on has to stay powered on
Amazon must be adequately motivated to find a way to power-down unused capacity. My guess is they have some kind of system to maximise this.
Yeah, I’ve experienced several instance retirements. Most with a fair bit of warning, one a few minutes after the instance stopped responding. I haven’t gotten a retirement warning in several years, so it seems they're doing something to mitigate hardware failures, although my infrastructure is small enough it could just be luck.
Plus Xen has live migrate now, so I assume AWS’s frankenxen would have it as well.
There is indeed a brief interrupt, which is why I said they can’t be too aggressive with it.
Anyways, I’m sure Amazon does what it can to power down machines, I just think they’re stuck leaving much the data center running because they can’t kick off running VMs.
I wonder about live migration. I imagine there must be some brief interruption even there.
> Many VMs are run indefinitely, so whatever machine they’re on has to stay powered on
Amazon must be adequately motivated to find a way to power-down unused capacity. My guess is they have some kind of system to maximise this.
[0] https://www.theregister.co.uk/2012/12/20/aws_ec2_servers_ret...