Asynchronous replication and synchronous replication of MySQL master-slave replication

Asynchronous replication: MySQL natively supports one-way, asynchronous replication. Asynchronous replication means there is a delay in copying data from one machine to another-most importantly this means that the data cannot be copied/applied to the slave at the same time when the application's transaction commit has been confirmed. Typically, this delay is determined by network bandwidth, resource availability, and system load. However, with the right components and tuning, replication can be done almost instantaneously.

Synchronous replication: Synchronous replication can be defined as data being submitted to one or more machines at the same time, usually through a well-known "two-phase commit". While this does give you consistency in multiple systems, it also degrades performance due to increased additional message exchange.

MySQL, which uses the MyISAM or InnoDB storage engine, does not natively support synchronous replication, but some technologies, such as the Distributed Replication Block device (DRBD), can provide synchronous replication on the underlying file system. Allow the second MySQL server to take over if the primary server is lost (using a replica of the second server). To learn more, see: http://www.drbd.org/

Asynchronous replication and synchronous replication of MySQL master-slave replication