Good point, I wonder if they didn't because that would have crippled capacity due to people rebooting, using up the patched hosts and leaving others without the ability to spin up VMs as it sounds like a significant % of hosts are bad at this point..

There is not enough capacity. I think Amazon did not make this decision lightly.

You must construct additional pylons.

This is normally what they do when they roll out forced reboots like this.

Note the forum posting says there isn't guarantee of being on an updated host...that is because the patching isn't complete across the region yet.

Ideally, that would be great. I doubt that would be an option though due to capacity. Would you rather stop/start your instance and risk a capacity error or have your impacted instances rebooted in 48 hours?

> Would you rather stop/start your instance and risk a capacity error or have your impacted instances rebooted in 48 hours?

Is there that little slack in Amazon's compute capacity? I would hope not! If there isn't capacity to start my instance back up, I would hope that hitting Stop would generate a dialog to the effect of "Hey there, you won't be able to start this instance back up if you stop it right now."

> Is there that little slack in Amazon's compute capacity?

I'm sure there's plenty of "slack" under most circumstances. However this affects the majority of users so all of them setting up new instances at the same time would likely be impossible.

For the scale of this reboot, they'd have to maintain 30-50% extra capacity which would likely be financially impossible at those rates.

Any slack capacity is waste, and Amazon sure hates that. Consider where the supply of the spot market comes from.

> Is there that little slack in Amazon's compute capacity?

Amazon's ability to deliver sharp prices does not come from leaving unused tin lying around in datacentres.

Amazon markets their cloud infrastructure as having the ability to scale up at a moment's notice. If they don't have excess capacity, where am I going to scale to? Back to a colo environment?

There very well could be. If this issue is related to only handful of instance types then there goes all that extra capacity.

Spot market anyone? Different regions, even different AZ's have different capacity.

Stop relying on long running instances. Design your infrastructure for failure. This is not Amazon's responsibility.

Stop assuming that everyone operates at Netflix scale. Not everyone wants to watch their database, memcached, and redis instances thrash all day as instances dance around from physical box to physical box.