Automatic MySQL Replication Fail-over Strategy I want to know that if replication is down due to some reason as if master is down then what strategy should be followed so that the replication is up instantly without manually intervening the process , i.e if replication is down when no DBA is available then how the automatic fail-over will take place.
MySQL 5.6 introduces Global Transaction Identifiers to replication, and complements these with new failover and switchover utilities which can automate fault recovery

You can learn more about replication in MySQL 5.6 here:
http://dev.mysql.com/tech-resources/articles/mysql-5.6-replication.html

You can also watch a tutorial demonstrating how these utilities work to provide self-healing clusters:
http://dev.mysql.com/tech-resources/articles/mysql-replication-utilities.html