[jseutter]

No, migrating did involve intervention from the account holder. More information here: https://aws.amazon.com/blogs/aws/ec2-classic-is-retiring-her...

It seems like AWS spent time, people and money to migrate customers off EC2 classic. They made a fairly good effort to automate the process and make it less painful for customers. For example: https://repost.aws/knowledge-center/ssm-migrate-ec2classic-v...

The original network was from an everyone-on-the-same-subnet model to a you get your own subnet, so yes, customer applications could break in the process. People do all sorts of non-smart things for good reasons, like hardcoding an ip address in /etc/hosts when a nameserver is down. And then they forget to change it back. To do these sorts of migrations well requires a sort of stick and carrot approach. The stick, which is we want to shut down this service and will eventually refuse you service, and the carrot, which includes automation, reminders that people need maintenance windows for their applications, clear directions, and above all, willingness to deal with people and actually talk to them.

[londons_explore]

Looking at that blog post, I think AWS could have done the migration for most users with no involvement of the user themselves.

In the ideal world, they would have written software to live-migrate VM's to the new platform and emulate the old networking.

Emulating old stuff should be pretty easy, because hardware moves on, and an instance back in 2006 probably had far lower performance expectations - and therefore even a fairly poor performance emulation will be sufficient to meet user needs.

[TheDong]

"emulate the old networking" is something that can't be done per customer, and the new platform makes networking per customer.

Let's say I have my aws account "account1", and my friend has their account "account2", both running classic. We could have both talked to each other's instances by their _private IPs_ even though they're in different accounts. AWS has no way of knowing those two instances are related, other than that they're both in classic.

Sure, AWS could make a global cross-account emulated flat network, but at that point, it's probably cheaper to just use the real thing, which was already built and functions... and at that point, you're not migrating them to "the new platform", but rather to "ec2 classic 2"

[londons_explore]

If there is a small number of classic users, a single special case in the code to have all classic users connected to a single network of an admin account seems very doable...

I wonder if perhaps part of the reason for not doing this was they were worried about malware spreading across that shared internal network from one VM without security patches to the next VM without security patches.

Even if that were the case, they could monitor all VM's on the classic network, and any VM which doesn't contact another users VM's for ~1 month would have the ability to do so be blocked.

[lclarkmichalek]

I wonder why they didn't do that in the 14 years since VPCs were introduced?