It’s not uncommon to promote a server from slave to master. One of the key things to protect your data integrity is to make sure that the promoted slave is permanently disconnected from its old master. If not, it may get writes from the old master, which can cause all kinds of data corruption. MySQL provides the handy RESET SLAVE command. But as we’ll see, its behavior has changed along with the MySQL versions and it’s easy to shoot yourself in the foot if you use it incorrectly. So how do you safely disconnect a replication slave?

In short

• For MySQL 5.0 and 5.1, run STOP SLAVE, CHANGE MASTER TO MASTER_HOST='' and then RESET SLAVE.
• For MySQL 5.5 and 5.6, run STOP SLAVE and then RESET SLAVE ALL.
• For all versions, ban master-user, master-host and master-password settings in my.cnf, …

Today’s blog post diving into the waters of the MySQL buffer pool is a cross-post from Groupon’s engineering blog, and is Part 1 of 2. Thank you to Kyle Oppenheim at Groupon for contributing to this project and post. We’ll be posting Part 2 on Thursday. I’ll be at the Percona Live MySQL Conference and Expo next week in Santa Clara, California so look for me there – I’d love to connect and talk more about MySQL buffer pools or anything else that’s on your mind!

There …

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 …

In preparing for this month’s Percona Live MySQL Conference and Expo, I’ve been reminiscing about the annual MySQL User Conference’s history – the 9 times it previously took place in its various reincarnations – and there are a lot of good things, fun things to remember.

2003 was the year that marked the first MySQL user conference independently organized by MySQL AB. It was called the “MySQL Users Conference” and took place at the Double Tree hotel near the San Jose airport with an estimated 500-600 people attending. Monty and David kicked-off the show with keynotes and I recall one of them saying something like, “12 …

We just released our first alpha of Percona XtraBackup 2.1 for MySQL and with it we included the ability to encrypt backups on the fly (full documentation here). This feature is different than simply piping the backup stream through the openssl or gpg binaries, which is what some people have used in the past. A big benefit of using the built-in encryption is that multiple CPU cores can be used for encryption (with the --encrypt-threads option). You can also combine compression and encryption, each using multiple CPU cores.

One advantage of …

5.6 has redefined MySQL performance and usability. Some great talks at the Percona Live MySQL Conference and Expo will provide insight into the new features and benefits of this major release. The conference is April 22-25, 2013 at the Santa Clara Convention Center and Hyatt Santa Clara.

Monday evening features the conference Welcome Reception where attendees can relax over food and beverages in the exhibition area following the day’s tutorials. After the Welcome Reception, at 6:30 pm, Oracle is hosting a reception to celebrate MySQL 5.6 going GA which is open to the public (but space is limited and pre-registration is required).

The MySQL 5.6 content continues Tuesday morning when …

Percona CEO Peter Zaitsev leads a track at Percona MySQL University in Raleigh, N.C. on Jan. 29, 2013.

Percona MySQL University, Toronto is taking place this Friday and I’m very excited about this event because it is a special opportunity to fit a phenomenal number of specific and focused MySQL technical talks all into one day, for free.

Over the course of the day we will cover some of the hottest topics in the MySQL space. There will be talks covering topics like MySQL 5.6, MySQL in the Cloud and High Availability for MySQL, as well as Percona XtraDB Cluster for MySQL. We have talks planned for nearly every …

Facebook is a major user of MySQL and has pushed the performance limits of the technology. Their MySQL experts have deep, hands on knowledge of the technology. I’m pleased to welcome Mark Callaghan, Software Engineer for Database Infrastructure at Facebook, back again this year to the Percona Live MySQL Conference & Expo to share his expertise. Mark was a keynote speaker at last year’s conference and will appear this year with a group of Facebook MySQL experts:

• Domas Mituzas, …

As part of Percona Remote DBA for MySQL service we recognize that reliable backups are one of the most important things we can bring to the table. In my experience handling emergencies, the single worst thing that can happen is finding out you don’t have backups available when some sort of data loss or catastrophic event occurs.

With our Remote DBA service we can take care of backups for you, what follows are some of the internals of our implementation.

What kind of outages can happen?

• Someone runs UPDATE or DELETE and forgets the where clause or filters weren’t quite right
• The application had a bug causing data to be removed or overwritten
• A table (or entire schema) was dropped …

I’m pleased to announce that Oracle is sending some of their top technical people to speak at the Percona Live MySQL Conference and Expo. The conference takes place April 22-25, 2013 at the Santa Clara Convention Center and Hyatt Santa Clara.

Tomas Ulin, VP, MySQL Engineering for Oracle, will present an invited keynote talk on “Driving MySQL Innovation” during the Tuesday morning opening keynotes. With the recent release of MySQL 5.6, conference attendees will hear about the latest developments of this major MySQL release.

In addition to Tomas, Oracle MySQL technologists will also lead three breakout …