On Tue, Apr 6, 2010 at 2:10 AM, Paul Prescod <p...@ayogo.com> wrote: > On Mon, Apr 5, 2010 at 4:48 PM, Tatu Saloranta <tsalora...@gmail.com> wrote: >> ... >> >> I would think that there is also possibility of losing some >> increments, or perhaps getting duplicate increments? > > I believe that with vector clocks in Cassandra 0.7 you won't lose > anything. The conflict resolver will do the summation for you > properly. > > If I'm wrong, I'd love to hear more, though.
I keep reading this in the list, but why would vector clocks allow consistent counters in a conflicting update? Say nodes A,B,C where A,B get concurrent updates, if we do read-and-set this does not seem useful as we'd end up with a vector <A:x+1,B:x+1> but why would x+1 be the correct value compared to x+2 ? Or are we imagining spreading pairs <key,INCR>, <key,DECR> in which we assume the writer client did not look at the existing value? -- blog en: http://www.riffraff.info blog it: http://riffraff.blogsome.com
