epaxos.go doesn't correctly check for fast quorum on fast path

[jiaochangyang]

A colleague and I have been digging into this code base, and it looks like there's only a relaxed majority requirement in the fast path code, rather than the stricter quorum sizes in the TLA+ and paper.

epaxos/src/epaxos/epaxos.go

Line 1111 in 791b115

//can we commit on the fast path?

and

epaxos/src/epaxos/epaxos.go

Line 1049 in 791b115

//can we commit on the fast path?

both simply check that >N/2

Is there some detail we are overlooking?

Thanks

[nibeshrestha]

There is a constant "DS" which has value 5. "DS" is being used to instantiate the no. of "deps" an instance has. So I believe, this code works for a system with at most 5 replicas. For 3 replica and 5 replica system, the size of fast quorum and slow quorum is same according to EPaxos spec.