[jitl]

I was expecting this to say “S3 append is buggy” or something. But really it just is saying “my specific application cannot replace making new files with append for a very specific reason”

The issue cited is that using append instead of writing a new file means losing put-if-absent consistency guarantee.

So… just don’t do that? Make the rule that a leader can append to a file it already wrote, but new process or newly elected leader must always start the next file in the sequence, and don’t design your system so that the append use-case needs at-most-once delivery or something. You can put a causal clock in each append chunk header or something if you want to stay as close as possible to the original system design.

Like, I will happily write pages of a WAL using append with no issues as long as my system isn’t multi-leader. ¯\_(ツ)_/¯