Google released some improved MySQL code this week. Some of the changes include:

   * SemiSyncReplication – block commit on a master until at least one slave acknowledges receipt of all replication events.
   * MirroredBinlogs – maintain a copy of the master's binlog on a slave
   * TransactionalReplication – make InnoDB and slave replication state consistent during crash recovery
   * UserTableMonitoring – monitor and report database activity per account and table
   * InnodbAsyncIo – support multiple background IO threads for InnoDB
   * FastMasterPromotion – promote a slave to a master without restart

Information Week Source:
informationweek.com/news/showA ...

Google Blog info about this:
google-code-updates.blogspot.c ...