onionoo is hardly reachable since about 17 hours ago.
Indeed. For some reason Onionoo saw an increase in requests from 700 to 4000 per second 24 hours or so ago.
There's now a third host answering Onionoo requests from a local cache, so that might improve the situation. (Thanks, weasel!)
Is this only externally facing or will this also cause onionoo to miss descriptors internally?
The former. If the hourly updater is overloaded, it will simply run less often than once per hour. But it won't miss any data.
Any ETA on when this will improve?
It should be better now. If it's still bad after the weekend, we'll make a new plan.
It got better after your email, but now it is back at 4 out of 5 atlas searches running into a backend error message.