Jay
> Scan ranges at a long interval Interesting, it may also solve the issue that too many tombstone key in memtable. Note you can hint the rocksdb to only scan...
What's the purpose of this PR?
> It'll be used to judge pending peer: whose (except witness) apply index is smaller than leader's truncated index Why it has to be apply index? Why can't matched be...
> For witness -> non-witness conf-change, we need to know when the snapshot has been applied. The witness or uninitialized peer would always report apply index of 0. And once...
> what if we want to do flow control based on slow apply, it still needs to trace apply index progress. Slow apply should not be measured by index. Instead,...
> Not want to deep into the details of slow apply. My point is the apply index fits the witness requirement, and it also can be used by other features....
Can you update the PR title to a more meaningful one?