It seems Google couldn’t wait to have their code evaluated for merging into the main source tree, and decided to release it to the general public as patches to 4.0.26 for the community to evaluate.
What have we added and enhanced?
The high availability features include support for semi-synchronous replication, mirroring the binlog from a master to a slave, quickly promoting a slave to a master during failover, and keeping InnoDB and replication state on a slave consistent during crash recovery.
The manageability features include new SQL statements for monitoring resource usage by table and account. This includes the ability to count the number of rows fetched or changed per account or per table. It also includes the number of seconds of database time an account uses to execute SQL commands.
Here’s their blog post announcing the release, a page with more details about the release, and just to make this page a bit useful, here are the direct links to the major releases by feature:
- 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