The rationale of the last commit/ack phase is to set the chosen value (here the mutation) in a durable storage (here into Cassandra) and reset this value to allow another round of Paxos.
More explanation in this blog post: http://www.datastax.com/dev/blog/lightweight-transactions-in-cassandra-2-0 For a detailed explanation of different Paxos phases, look at those slides: http://www.slideshare.net/doanduyhai/distributed-algorithms-for-big-data-geecon/53 On Tue, Aug 25, 2015 at 6:07 PM, ibrahim El-sanosi <ibrahimsaba...@gmail.com > wrote: > > > > > What an excellent explanation!!, thank you a lot. > > By the way, I do not understand why in lightweight transactions in > Cassandra has round-trip commit/acknowledgment? > > For me, I think we can commit the value within phase propose/accept. Do > you agree? If not agree can you explain why we need commit/acknowledgment? > > > > Regards, > > > > ibrahim >
