It's the time of the year again: You have 2 more weeks to submit a great proposal to the biggest and baddest MySQL Conference: Percona Live MySQL Conference and Expo 2013 (Santa Clara). Like many things in the MySQL community, this conference has also gone through a transformation over the past 3 years. But last year the growing pains and uncertainty ended with Percona putting up a great show. Attendance was up again (over 1000) and there was a sense of energy and excitement for the future of MySQL. If you are like me and like to dwell in nostalgia (so that you can get into the right mood for submitting great proposals) my coverage of last year's conference is found here: part 1,

So, what impact does enabling the slow query log have on MySQL?

I decided to run some numbers. I’m using my laptop, as we all know the currently most-deployed database servers have mulitple cores, SSDs and many GB of RAM. For the curious: Intel(R) Core(TM) i7-2620M CPU @ 2.70GHz

The benchmark is going to be:
mysqlslap -u root test -S var/tmp/mysqld.1.sock -q 'select 1;' --number-of-queries=1000000 --concurrency=64 --create-schema=test

Which is pretty much “run a whole bunch of nothing, excluding all the overhead of storage engines, optimizer… and focus on logging”.

My first run was going to be with the slow query log on. I’ll start the server with mysql-test-run.pl as it’s just easy:
eatmydata

There has been a lot of talk about MySQL 5.6 replication improvements. With few exceptions, what I have seen was either marketing messages or hearsay. This means that few people have really tried out the new features to see whether they meet the users needs.

As usual, I did try the new version in my environment. I like to form my own opinion based on experiments, and so I have been trying out these features since they have appeared in early milestones.

What follows is a list of (potentially) surprising results that you may get when using MySQL 5.6.
All the examples are made using MySQL 5.6.6.

Gotcha #1 : too much noise

I have already mentioned that MySQL 5.6 is too verbose when creating data directory. This also means that your error

I recently released a new version of the Bazaar plugin for Jenkins. This release was inspired by a problem we noticed at Percona. It is:

• run “bzr revert” after a pull, as if you have a directory that is removed and re-added while having unknown files in said directory (e.g. build artifacts), you would end up in a very bad place (this is a BZR bug, so we work-around it with a “bzr revert”).

The update has already appeared in the Jenkins update centre, so you should already be able to upgrade to it.

From the desk of your new Bazaar plugin for Jenkins maintainer, I give you Version 1.18.

This release has two good bug fixes:

• UI fix for checkout option (JENKINS-12261)
• Auto-recover from corrupt BZR branches (e.g. bzr branch/checkout killed at inopportune moment) by cleaning the workspace and trying again (this is now default behaviour, best used with the Jenkins SCM retry count feature being > 1)

We’ve been running the same code as this release at Percona for about 2 months now (the second bugfix was one I wanted to test first before submitting upstream). This is the big fix that fixed all our problems with using bazaar with Jenkins in a large deployment.

For Drizzle and for all of the projects we work on at Percona we use the Bazaar revision control system (largely because it’s what we were using at MySQL and it’s what MySQL still uses). We also use Jenkins.

We have a lot of jobs in our Jenkins. A lot. We build upstream MySQL 5.1, 5.5 and 5.6, Percona Server 5.1, Percona Server 5.5, XtraBackup 1.6, 2.0 and 2.1. For each of these we also have the normal trunk builds as well as parameterised ones that allow a developer to test out a tree before they ask for it to be merged. We also have each of these products across seven operating systems and for each of those both x86 32bit and 64bit. If we weren’t already in the

Since I have been discussing scripting lately I thought I would continue with another topic I touched on briefly - backups.

I have written and modified the following script over the last few years. I have used it (and continue to use it) with multiple clients. It uses Percona's Xtrabackup to take the backup (although it can be easily modified to use mysqldump instead).

First the script

-----------------------------------------------------------------------------------------------------------------

#!/bin/bash
SAVEIFS=$IFS
IFS=$""
day_of_week=`date +%a`
backup_dir=/mysql-backup/
logfile=/root/backup_log.txt
report=/tmp/report.txt
servername=slave1
email=bmurphy@paragon-cs.com
password=`cat /root/.ssh/.backup_password`

# run backup
echo ' ' > $report
echo 'The backup is now beginning:'

You could say: what could be the reason for having really big number of tables? Just design the application properly! It’s not always that easy. And this post isn’t really about arguing whether having many tables is good or not, it’s about what happens in terms of memory usage if you already reached that point.

Btw what do I mean by *many*? From my experience it’s tens of thousends or even millions rather than hundreds.

The inspiration for me to write this post was strong desire to try out the latest declared improvements in that area announced to be done in MySQL 5.6. _1

What I did was a very simple

This is the second and final part of my notes from the MySQL conference. In this part I'll focus on the technical substance of talks I saw, and didn't see.

More than ever before I was a contributor rather than attendee at this conference. Looking back, this resulted in seeing less talks than I would have wanted to, since I was speaking or preparing to speak myself. Sometimes it was worse than speaking, for instance I spent half a day picking up pewter goblets from an egnravings shop... (congratulations to all the winners again :-) Luckily, I can make up for some of that by going back and browse their slides. This is especially important whenever 2 good talks are scheduled in the same slot, or in the same slot when I was to speak. So I have categorized topics here along various axes, but also along the "things I did see" versus "things I missed"

I have finally recovered from my trip to Santa Clara enough that I can scribble down some notes from this year's MySQL Conference. Writing a travel report is part of the deal where my employer covers the travel expense, so even if many people have written about the conference, I need to do it too. And judging from the many posts for instance from Pythian's direction, Nokia is perhaps not the only company with such a policy?

Baron's keynote

There has usually always been something that can be called a "soft keynote". Pirate Party founder Rick Falckvinge speaking at a database conference is a memorable example (I still keep in touch with him, having met him at the Hyatt Santa Clara). This year there was one less day, and therefore less keynotes. The soft keynote was therefore taken care of by Baron using some time out of Peter's opening keynote.

The Percona Live MySQL Conference and Expo 2012 is over. Together with the SkySQL solutions day, it has kept me occupied for 4 full days, from early morning to late at night.

I have to say that I am pleased. The quality of the organization was very high, with a very good lineup of speakers and an excellent technical support.

As usual, I have learned a lot during this week, either directly, by attending talks, or indirectly, by meeting people who told me what was juicy at the talks that I had missed. And I have met new interesting people, and caught up with the people that I know already.

This conference was particularly intense also because I got myself involved in 5 talks, which was probably more than I should have. How did

After 15 years of slide show technology, I thought that we need to change the way we do presentations. And since I am advocating radical changes, I will eat my own dog food and be the first to present a MySQL session using 3D technology.

Since watching Avatar a few years ago, I thought that using this technology would make my presentations truly amazing. However, two years ago a 3d projector was prohibitively expensive. Now, instead, it is affordable, and fits in my briefcase!

What I needed, though, was a compelling reason for using 3d vs. traditional presentations. And I found it. As I have mentioned recently, I am working with the coolest replication technology on earth. Explaining this technology

MySQL version 4.1 was quite revolutionary. The main reason for that was support for sub-queries.1

However since then MySQL users were rather discouraged to use that functionality, basically due to the implementation’s poor performance  and forced to build complicated queries based on joins rather than on subqueries.

Of course you can do some effort to optimize your subquery with sometimes very good results2. Not always it’s easy or even possible if you can’t change the code though.

You’d say it’s

The second week of April will be quite a busy one

Tuesday, April 10

April 10th is Tutorial day at the Percona Live MySQL Conference and Expo.

On that day, I will present a classic: MySQL Replication 101. This is a topic traditionally presented by a MySQL engineer. However, since Oracle seems not to be eager to send anyone to the conference, I volunteered to the task, and I have let everyone know that, if Oracle change its mind and sends some engineers at the conference, I will happily have one of my former colleagues from the replication team as co-speaker.

Wednesday, April 11

The conference will be in full swing when the regular sessions (and the keynotes!) start. From my side,

I for one can say that I’m truly excited that MariaDB will be part of Percona Live Santa Clara. The MariaDB session list includes:

• A tutorial: Improving MySQL/MariaDB query performance through optimizer tuning by Timour Katchaounov and Sergey Petrunia. You can benefit from this even as a stock MySQL user naturally.
• MySQL Plugins – why should I bother? by Sergei Golubchik is again something that isn’t only MariaDB specific since MySQL also has a plugin architecture. I don’t know if Sergei will talk about

Several months ago I suggested having lightning talks at Percona Live MySQL Conference and Expo 2012, and I also offered to help.

Then I forgot about that for a while, until I saw the announcement that there was a call for Lightning Talks. Great! I submitted two proposals, and asked my colleagues to do the same, and also encouraged many good speakers I know to submit something.

The deadline for lightning talks submission passed, and I was told that my offer to help had been accepted, and I was in charge of lightning talks! OK. I would have preferred being told before the CfP, but an offer to help is an offer to help, and thus I went through the motions of evaluating the talks, sending notices to the winners, consoling the losers, and giving hope to the few brave ones who will replace the

Oh boy, I'm starting to feel the stress of having to prepare a little bit of this and a little bit of that for the upcoming MySQL User Conference (Santa Clara, April 10 to 13). But I wanted to also jump on this meme and list a few sessions I definitively want to attend:

I'm speaking, so I suppose I need to attend:

• How to evaluate which MySQL High Availability solution best suits you. This 3 hour tutorial I'm co-presenting with Ben Mildren, a former Nokia collague who now works with Pythian.

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