A colleague and I have been looking at GTID on MySQL recently and you may be interested in the blog post that results from that. You can see it here. http://blog.booking.com/mysql-5.6-gtids-evaluation-and-online-migration.html.

March 3, 2014 By Severalnines

Hybrid replication, i.e. combining Galera and asynchronous MySQL replication in the same setup, became much easier with MySQL 5.6 and GTID. Although it was fairly straightforward to replicate from a standalone MySQL server to a Galera Cluster, doing it the other way round (Galera → standalone MySQL) was a bit more challenging. At least until MySQL 5.6 and GTID. 

There are a few good reasons to attach an asynchronous slave to a Galera Cluster. For one, long-running reporting/OLAP type queries on a Galera node might slow down an entire cluster, if the reporting load is so intensive that the node has to spend considerable effort coping with it. So reporting queries can be sent to a standalone server, effectively isolating Galera from the reporting load. In a belts and suspenders approach, an …

Will be giving a lightning talk at Percona Live 2014 – santa clara :)

In the world of replication, The Binlog is every ones favorite. 

But what about the Relay log, Don't you feel it can do more ?

Yes, It can. How about, if it can serve the purpose of the GTID 

feature without GTID.

https://www.percona.com/live/mysql-conference-2014/sessions/relay-log-unsung-hero

#MySQL  ( alternative to GTID )  #gtid

Yesterday I’ve put some new features into the ansible’s mysql_replication module, because we are planning to move to GTID based replication from the good old binlog position based one, and the module wasn’t aware of.

gtid_replication

This parameter can be either 0 or 1, defaults to 0. If set to 1 the replication will be threaded as GTID based replication.

warnings_filtered

This parameter threats the warnings, because MySQL 5.6 complaints a lot more than the previous versions. (For example, if the replication is not encrypted with SSL/TLS.) This could break our playbooks, so you can set it to all, warnings, none (defaults none). Speaks for itself, all means all warnings/errors will be shown, if warnings set, then only the errors will be shown, and the warnings supressed, and if none then that means, every message will be show …

We are in the middle of switching to GTID based replication from the good old logfile & log position based replication.

But what is GTID? GTID is an abbreviation of ‘GLOBAL TRANSACTION ID’ what speaks for itself: each transaction of a mysql cluster got its globally unique transaction ID, and the DBA have not spend time with positioning slaves, as well as we don’t have to ‘freeze’ any of the servers because of a master failover. The only thing we have to care about: to know what server should be used as a replication master.

OK, what was the problem with the old file-based replication?

Check out this scenario: you have two master servers, called db-master1 and db-master2 and two slaves db-slave1 db-slave2. All the writes are happening on db-master1 and this will replicating to the slaves and the failover master too.

So you have your replication set up, and everything works well. But there is a point …

MySQL 5.6 has been GA for just over a year now. See MySQL 5.6.10 Release Notes.  Congratulations on your birthday! That is quite a long time. I was using it earlier in production because it worked and could do things that 5.5 could not do, but earlier versions were to use at your own risk, and indeed if prodded incorrectly would fall on the floor. That is fair enough because they were work in progress, yet if you poked them the right way they did a very good job.  Those dev versions have been long since upgraded which is good so they do not need quite as much care and attention.

So from where I see 5.6 it works very well. One big change that has made a large difference but which I think a lot of people may not really understand or use is the …

Async and PXC

A common question I get about Percona XtraDB Cluster is if you can mix it with asynchronous replication, and the answer is yes!  You can pick any node in your cluster and it can either be either a slave or a master just like any other regular MySQL standalone server (Just be sure to use log-slave-updates in both cases on the node in question!).  Consider this architecture:

However, there are some caveats to be aware of.  If you slave from a cluster node, there is no built in mechanism to fail that slave over automatically to another master node in your cluster.  You cannot assume that the binary log positions are the same on all nodes in your cluster (even if they start binary logging at the same time), so you can’t issue a CHANGE MASTER without knowing the proper binary log position to start at.

…

The main benefit of using GTIDs is to have much easier failover than with file-based replication. We will see how to change the replication topology when using GTID-based replication. That will show where GTIDs shine and where improvements are expected.

This is the second post of a series of articles focused on MySQL 5.6 GTIDs. You can find part one here.

Our goal will be to go from setup #1 to setup #2 on the picture below, following various scenarios:

For these tests, all servers are running on 127.0.0.1 with ports ranging from 10000 for s0 to 10004 for s4.

Scenario #1: All slaves have processed all the writes

This is the easiest case, we will …

Global Transactions Identifiers are one of the new features regarding replication in MySQL 5.6. They open up a lot of opportunities to make the life of DBAs much easier when having to maintain servers under a specific replication topology. However you should keep in mind some limitations of the current implementation. This post is the first one of a series of articles focused on the implications of enabling GTIDs on a production setup.

The manual describes very nicely how to switch to GTID-based replication, I won’t repeat it.

Basically the steps are:

• Make the master read-only so that the slaves can execute all events and be in sync with the master
• Change configuration for all servers and …

The MySQL Utilities Team is pleased to announce our latest release, version 1.2.1. This release contains many quality improvements and enhancements to the HA and Replication utilities. The following lists some of the most significant improvements.

• Improved transaction gathering algorithm for failover
  • Skips slaves that are already caught up
  • Ensures all transactions in the relay logs on the slaves are executed first
• External scripts in mysqlfailover and mysqlrpladmin now receive the old and new master information
• Improved demote master handling for switchover
• Improved connection error handling
• Quoting of tables and database names has been improved
• Login-path feature now reads port and socket

The utilities team continues to focus on improving usability, making features easier to use, and …