(mysql.info) replication-intro

(mysql.info) replication-implementation
 
 6.1 Introduction to Replication
 ===============================
 
 MySQL features support for one-way, asynchronous replication, in which
 one server acts as the master, while one or more other servers act as
 slaves. This is in contrast to the _synchronous_ replication which is a
 characteristic of MySQL Cluster (see  ndbcluster).
 
 In single-master replication, the master server writes updates to its
 binary log files and maintains an index of those files to keep track of
 log rotation. The binary log files serve as a record of updates to be
 sent to any slave servers. When a slave connects to its master, it
 informs the master of the position up to which the slave read the logs
 at its last successful update. The slave receives any updates that have
 taken place since that time, and then blocks and waits for the master
 to notify it of new updates.
 
 A slave server can itself serve as a master if you want to set up
 chained replication servers.
 
 Multiple-master replication is possible, but raises issues not present
 in single-master replication. See  replication-auto-increment.
 
 When you are using replication, all updates to the tables that are
 replicated should be performed on the master server. Otherwise, you
 must always be careful to avoid conflicts between updates that users
 make to tables on the master and updates that they make to tables on
 the slave.
 
 Replication offers benefits for robustness, speed, and system
 administration:
 
    * Robustness is increased with a master/slave setup. In the event of
      problems with the master, you can switch to the slave as a backup.
 
    * Better response time for clients can be achieved by splitting the
      load for processing client queries between the master and slave
      servers. `SELECT' queries may be sent to the slave to reduce the
      query processing load of the master. Statements that modify data
      should still be sent to the master so that the master and slave do
      not get out of synchrony. This load-balancing strategy is
      effective if non-updating queries dominate, but that is the normal
      case.
 
    * Another benefit of using replication is that you can perform
      database backups using a slave server without disturbing the
      master. The master continues to process updates while the backup
      is being made. See  backup.
Info Catalog
(mysql.info) replication
(mysql.info) replication-implementation
automatically generated byinfo2html