(1) When a txn reach a replica out of order, where replica store the txn? In a file or memory?
(2) Does replica acknowledge the txn in order? This mean: replica will not ack the new txn before it ack the old one?
(3) As we know, when master cannot get ack from the majority of replicas, it will get NO PERM event.
The question is: If we don't get NO PERM for a txn at time t1, does this mean all of txn before t1 are delivered to a majority of replicas?