Their previous consistency was RAW, but not RAU (for most regions. I think us-east-1 was missing RAW consistency for quite a while).
After a write, you would _always_ be able to read the key you just wrote.
After an update, you could get a stale copy of the key if your subsequent read hit a different server.
Re:S3 Strong Consistency
by heartofgold on Tuesday December 01, 2020 @08:45PM
(#25272357)
Not quite _always_. There were some documented caveats... the one I hit before was:
Read nonexistent key, followed by a write of that same key, and then a subsequent read could return a stale read saying it didn’t exist. (even though it had just been written for the first time.)
Anyway I am glad to see these gaps and caveats have been closed.
like if you had tried to read a non-existent key, then wrote to it, it might continue to appear to not exist for a minute?