In this case, num_last appears to be sufficient: - the 'last' message is only sent in response to a collect, - a 'collect' is only sent once for a given value of pn, - a 'last' message with a mismatched pn is ignored or triggers a new collect round, - and the messenger layer provides exactly-once delivery. That said, num_last could be replaced with a set<int> to harden the code a bit. sage On Tue, Jan 19, 2021 at 5:57 AM Afonso Fernandes <afonsofernandes@netcabo.pt> wrote:

Hello,

I am studying the ceph paxos implementation. In handle_last, the leader counts the replies to collect phase by incrementing the variable num_last and without checking if the reply is duplicated (however, in handle_accept, the leader keeps a set of peons that replied, in variable accepted). Why does the leader not keep a set of peons that replied in the collect phase, similar to what it does later in function handle_accept?

Thanks, Afonso _______________________________________________ Dev mailing list -- dev@ceph.io To unsubscribe send an email to dev-leave@ceph.io