I’m sitting here in the lounge at SFO thinking back on the last week, the majority of which has been spent meeting my new workmates and attending the Percona MySQL conference.

For me it has been as much of a family reunion as it has been about seeing the wonderful things going on in MySQL.

Having joined Continuent last month after an ‘absence’ in NoSQL land of almost 2.5 years, joining the MySQL community again just felt like coming home after a long absence. And that’s no bad thing. On a very personal level it was great to see so many of my old friends, many of whom were not only pleased to see me, but pleased to see me working back in the MySQL fold. Evidently many people think this is where I belong.

What was great to see is that the MySQL community is alive and well. Percona may be the drivers behind the annual MySQL conference that we have come to know, but …

It was a busy day at Percona Live MySQL Conference and Expo 2013. After the regular sessions, there were the traditional MySQL Community Awards, and two entities close to me were among the winners.

• My company, Continuent won the award as Corporate Contributor of the year;
• My pet project of the last 7 years, MySQL Sandbox, won the award as Application of the year 2013.

Thanks to the MySQL community for these awards. They give me (and my colleagues) a goos feeling of appreciation.

The day was even more successful for four major occurrences that contributed to my wellness:

• …

For me, the biggest news in the last 24 hours so far has been:

1. SkySQL merges with Monty Program, developers of MariaDB. This of course affects me directly and leads to a change in affiliation in a few months.
2. TokuDB goes opensource. I think this is really big news. Beyond just the fact that it can now be a storage engine in the main MariaDB tree, I love the work they’re doing to extend it to be an engine for MongoDB as well.
3. …

Join Continuent, SkySQL and MariaDB for a day of free tutorials and interactive discussions around the MySQL and Maria databases, the Cloud, and High Availability, immediately following Percona Live: MySQL User Conference and Expo 2013.

Robert Hodges (CEO, Continuent) and Edward Archibald (CTO, Continuent) will be talking about "Scalable MySQL Operation in the Cloud with Continuent Tungsten" at

The Percona Live MySQL Conference and Expo begins next Monday and runs April 22-25, 2013. Attendees will see great keynotes from leaders in the industry including representatives from Oracle, Amazon Web Services, HP, Continuent, and Percona. They can also participate in thought provoking Birds of a Feather sessions on Tuesday night and the Wednesday night Community Networking Reception will be fun and entertaining with the presentation of the Community Awards and the Lightning Talks.

If you cannot attend the entire Percona Live MySQL Conference but want to take advantage of the keynotes, BOFs, and Community Networking …

I’ve just completed my first month here at Continuent, strangely back into the MySQL ecosystem which I have been working in for some time before I joined CouchOne, and then Couchbase, two and half years ago. Making the move back to MySQL is both an experience, and somehow, comfortable…

Continuent produce technology that makes for easier replication between MySQL servers and, more importantly, more flexible solutions when you need to scale out by providing connector and management functionality for your MySQL cluster. That means that you can easily backup, add slaves, and create complex replication scenarios such as multi-master, and even multiple-site, multiple-master topologies. This functionality is split over two products, Continuent Tungsten, which is the cluster management product, and the open source Tungsten Replicator, which provides the basic replication functionality.

Those who know me well will know that I am no fan …

In the first part of this article we examined the types of conflicts and their causes. In this part, we will analyse some of the methods available to deal with conflicts.

Pessimistic locking (or: conflicts won't happen)

Applicability: synchronous clusters with 2pc

We've covered this topic in the previous article, but it's worth repeating. If you use a synchronous cluster, you don't have conflicts. For example, MySQL Cluster ensures consistent data with updates coming from different nodes. However, MySQL Cluster is not a replacement for a MySQL server, and it has severe limitations.

Optimistic locking

Applicability: synchronous clusters without 2pc (Galera)

Conflicting transactions proceed on different nodes with local locking. The last one then …

What is a conflict?

Readers of this blog know that one of my favorite tools, Tungsten Replicator, can easily create multi-master replication topologies, such as all-masters, star, fan-in. While this is good news for system designers and ambitious DBAs, it also brings some inconvenience. When you allow updates to happen in more than one master, you risk having conflicts. You may have heard this term before. For the sake of clarity, let's define what conflicts are, before analyzing each case in detail.

You have a conflict when several sources (masters) update concurrently the same data in asynchronous replication.

It's important to stress that this happens with asynchronous replication. In a truly synchronous cluster, where all data is kept consistent through 2-phase …

The Percona Live MySQL Conference and Expo 2013 is almost 1 month away. It's time to start planning, set the expectations, and decide what to attend. This post will give a roundup of some of the sessions that I recommend attending and I look forward to.

First, the unexpected!

After much talk and disbelief, here they come! Oracle engineers will participate to the Percona Live conference. This is wonderful! Their participation was requested by the organizers, by the attendees, and by community advocates, who all told the Oracle management how important it is to be in this conference. Finally, they have …

Extract from THE SCALE-OUT BLOG by Robert Hodges (CEO, Continuent)http://scale-out-blog.blogspot.com Data management is undergoing a revolution. Many businesses now depend on data sets that vastly exceed the capacity of DBMS servers. Applications operate 24x7 in complex cloud environments using small and relatively unreliable VMs. Managers need to act on new information from those systems in