Starting with MySQL 5.5 it is possible to configure semi-synchronous replication. As you probably know, by default, MySQL replication is asynchronous.  Asynchronous replication means that events/transactions applied on one server are not immediately applied on the other one. In the specific context of MySQL such behavior means that the MySQL Master writes transactions/events to the local binary logs, however it has no idea when the slave(s) will get and process them. Of course such configuration can lead, in case of failover, to some transaction loss since there is no guaranty that the transactions have been transmitted on the standby server(s).

One more DRBD tutorial, this time I will describe howto setup MySQL with DRBD (Distributed Replicated Block Device). Purpose This document describes how to to setup a failover system with MySQL and DRBD (Distributed Replicated Block Device). Introduction In this tutorial we will setup two Debian Linux nodes with a DRBD volume. MySQL will be [...]

So you have created your standby database using the RMAN DUPLICATE command, you have set the ARCHIVE_LAG_TARGET to maintain a minimum lag target, and you have sorted out those nasty datafile missing errors using automatic file management. You’ve even added standby redo logs to improve the Mean Time To Recovery (MTTR). Now management are demanding [...]