No they are not. I just want to understand. On Wednesday, August 8, 2018, Dmitriy Pavlov <dpavlov....@gmail.com> wrote:
> Hi John, > > Are these questions related to some contribution? > > Sincerely, > Dmitriy Pavlov > > ср, 8 авг. 2018 г. в 3:18, John Wilson <sami.hailu...@gmail.com>: > > > Hi, > > > > Assume the following: > > > > > > - I have a transaction coordinator and two primary nodes with 0 backup > > nodes. > > - Persistence store is enabled. > > - I'm running a transaction in pessimistic mode with serializable > > isolation. > > > > I have these questions: > > > > 1. What exactly happens during the prepare phase? Only acquiring locks > > on the two primary nodes? Or do the primary nodes themselves, in > > addition > > to acquiring locks, write to their respective WAL a TxRecord with a > > "begin > > prepare" info? > > 2. Assume locks have been acquired successfully, would the nodes then > > write a "prepared" TxRecord to WAL before returning a "Yes" vote to > > coordinator? > > 3. When the coordinator sends a commit message, would each node write > > the key-values to the DataRecord and a commit to the TxRecord before > > returning to coordinator? > > > > > > Overall, I'm trying to understand what happens exactly during prepare and > > commit phases and when the key-values involved in the transaction are > > actually written; as well as the exact updates that are written to the > WAL > > files in each phase. > > > > appreciate your response. > > > > Thanks, > > >
