[EMAIL PROTECTED] wrote: > > > > > > Darren, can you clarify this? Why does it send that message? How does > > it allow commits not to wait for ordered writesets? > > > > There are two channels. One for total order writesets > (changes to the DB). The other is simple order for > aborts, commits, joins (systems joining the replica), etc. > The simple channel is necessary, because we don't want to > wait for total ordered changes to get an abort message and > so forth. In some cases you might get an abort or a commit > message before you get the writeset it refers to. > > Lets say we have systems A, B and C. Each one has some > changes and sends a writeset to the group communication > system (GSC). The total order dictates WS(A), WS(B), and > WS(C) and the writes sets are recieved in that order at > each system. Now C gets WS(A) no conflict, gets WS(B) no > conflict, and receives WS(C). Now C can commit WS(C) even > before the commit messages C(A) or C(B), because there is no > conflict.
Oh, so C doesn't apply A's changes until it see A's commit, but it can continue with its own changes because there is no conflict? -- Bruce Momjian | http://candle.pha.pa.us [EMAIL PROTECTED] | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073 ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
