Interesting - this was randomly in my feed but indeed today, I upgraded my server and didn't know at the time why all the apt requests were so slow. That being said, it sped up to full over time - I wonder if this is actually an effect of the DDoS or they added some infra to throttle at first and eventually determine if an IP is making valid requests.
I had no issue with regular distro update channels (those have mirrors all over) but couldn't get updates from PPAs (i.e. third-party). Feels backwards a bit.
Canonical/Ubuntu have been under DDoS for more than 15h
https://news.ycombinator.com/item?id=47972213