In the previous post of this series we saw how you could use mysqlrpladmin to perform manual failover/switchover when GTID replication is enabled in MySQL 5.6. Now we will review mysqlfailover (version 1.4.3), another tool from the MySQL Utilities that can be used for automatic failover.

Summary

• mysqlfailover can perform automatic failover if MySQL 5.6′s GTID-replication is enabled.
• All slaves must use --master-info-repository=TABLE.
• The monitoring node is a single point of failure: don’t forget to monitor it!
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I have previously written about the new replication protocol that comes with GTIDs in MySQL 5.6. Because of this new replication protocol, you can inadvertently create errant transactions that may turn any failover to a nightmare. Let’s see the problems and the potential solutions.

In short

• Errant transactions may cause all kinds of data corruption/replication errors when failing over.
• Detection of errant transactions can be done with the GTID_SUBSET() and GTID_SUBTRACT() functions.
• If you find an errant transaction on one …

I was giving a replication talk at Ohio Linux Fest last week and we touched a little bit on the MySQL Failover Utility and how it works with MySQL 5.6 .

The first thing that this along with Innodb and other replication enhancements are big GPL offerings from Oracle to the community.

First the usage:

[root@mysql-master python]# ./mysqlfailover --help
Usage: mysqlfailover --master=roo@localhost --discover-slaves-login=root --candidates=root@host123:3306,root@host456:3306

mysqlfailover - automatic replication health monitoring and failover

....

  --candidates=CANDIDATES
                        connection information for candidate slave servers for
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With all of the new news coming out right now, it can be easy to miss or overlook some of the new features.

While there’s been a lot of talk about MySQL 5.6 Replication, I specifically wanted to mention the new ‘mysqlfailover’ and ‘mysqlrpladmin’ utilities.

These are two new MySQL replication utilities (results of the new Global Transaction Identifiers (GTIDs) in MySQL 5.6).

Let me quote the MySQL 5.6 Replication article for both of these utilities:

mysqlfailover

“Provides continuous monitoring of the replication topology, enabling failover to a slave in the event of an outage on the master.

The default behavior is to promote the most up-to-date slave, based on …