During the last months we’ve worked hard on a new and exiting project!

“We’re making it easier

to show your databases in a glance”

I’m very proud to reveal the project for the first time because I am convinced that Glimpsee will change the way you “watch” the status of your databases…

Glimpsee is not another monitoring tool, it is the easiest way we’ve found to make DBA’s life easier.

I can’t say more about Glimpsee at this point but keep in mind these few words: simple, simple and… simple!

An alpha release of Glimpsee is already running for a lucky few. Register now to be the firsts to discover Glimpsee!
 

www.glimpsee.net

Follow @TeamGlimpsee

Twitter, RSS feeds (yes Google, I still use RSS), Planet MySQL and infiltrators were my best friends during this crazy week.

I would like to summarize the major announcements and events occurs during this tenth edition.
 

Oracle at Percona Live!

 
Yes, Oracle was at Percona Live 2013 and it was for the best.
I invite you to watch this keynote from Tomas Ulin about Oracle’s Investment in MySQL, read this post from Sheeri and this one from Mikael Ronstrom.
Oracle promises a future for MySQL and I’m sure many of you were expecting this signal.

MySQL 5.7 and MySQL Applier for Hadoop were also announced during the conference.
MySQL Applier reveals a promising use case for the binary log API.
You can read this first look of MySQL 5.7 by Stewart Smith.
 

TokuDB and Tungsten Replicator become open source

 
TokuDB is now open source via a community edition! (An enterprise edition remains available)
The MySQL, MariaDB or Percona users can now freely use TokuDB.
And this engine deserves your attention, for more informations : http://www.tokutek.com/2013/04/announcing-tokudb-v7-open-source-and-more/

Tungsten Replicator is now 100% open source. You no longer have excuses to not use this tool.
Continuent was corporate contributor of the year through the MySQL community awards 2013.
 

SkySQL + MariaDB = Love (the community)

 
The next generation of open source database company was born, SkySQL merges with MariaDB Developers. This merge doesn’t affect the MariaDB Foundation, MariaDB will survive!
In the same time Wikipedia adopts MariaDB and shares his experience with the community.

Honestly, I’ve never really understand why SkySQL and MariaDB was two separate companies because the SkySQL’s message was confused.
From now, you can’t be surprised that SkySQL highlights MariaDB and it’s a good point because MariaDB is a great product.
This may affect the independence of SkySQL on MariaDB competitors but I’m convinced that people behind SkySQL could surprise you.

And the new SkySQL/MariaDB becomes a strong alternative to Oracle.
The ping pong between Oracle and MariaDB on their respective resources affected to MySQL/MariaDB development is also quite funny and interesting.

However, I think that MariaDB should stop criticizing Oracle and should focus and communicate more on its own features.
This kind of message is a perfect exemple of counterproductive communication :
(I know this comes from zdnet but reflects what MariaDB proclaims usually)

Look out, Oracle: SkySQL and MariaDB join forces by @sjvn on zdnet j.mp/15EWBva

— MariaDB (@mariadb) 23 avril 2013

MariaDB deserves better, but this is only my opinion.
 

In the meantime…

 
.. you can pin on a map where you come from.
HP, Amazon, Continuent and Percona talks about the impact of MySQL and its future in the cloud.
- Brian Aker (HPCloud) asked Simone Brunozzi (AWS) : what is the engine of DynamoDB?
- Simone : we don’t disclose
- Brian : it’s MySQL!

Peter Zaitsev evokes the JaSON generation of developers.

LeapMotion announce a new shipping date, you will have to wait another 3 months.

Incredible small data stats from Facebook, again…

“the best answer of 99.9% database optimization questions is ‘it depends’”, really?

Some amazing pictures of a rather unusual booth appear on my twitter timeline.
And this post from Sheeri caught my attention, the comments too.
I believe that if someone is uncomfortable in a conference such as perconalive, there is a problem… (even if this affects only one person)
 

Slides and what’s next?

 
Slides from the conference are now available.
You can find these slides and much more on [Plus].
Next steps will be MySQL Connect 2013 and Percona Live London 2013 (hope to see you there)

Continue to follow me on Twitter or Facebook for the latest news about the MySQL Community.

And don’t forget to have fun…

MySQL Conference & Expo

2013

LIVE BLOG!

This year again, the MySQL Conference and Expo, hosted by Percona, smells like a wonderful event.
I haven’t the chance to attend this event but I would like to share with you the soul of this one.
I’ll try to share latest news, tweets and slides from the event in this live post.

Stay tuned and come back!

Breaking news!

• LATEST : See you next year!
• MySQL 5.7 is coming… : http://bit.ly/11zENgT
• SkySQL Merges With MariaDB : http://bit.ly/15DRtHL
• Wikipedia adopts MariaDB : http://bit.ly/11zTrDo
• Continuent Tungsten Replicator Is Now 100% Open Source : http://bit.ly/YGmC5V
• TokuDB v7: Open Source and More! : http://bit.ly/11yG086

highlighted tweets

“JSON Generation of Developers” awesome term by Peter Z. during the keynote. #perconalive

— Singer Wang (@SingerWang) 24 avril 2013

MySQL Community Awards 2013 – And the winners are… openlife.cc/blogs/2013/apr… #perconalive

— Henrik Ingo (@h_ingo) 25 avril 2013

MySQL 5.6 stats: 191 WLs, 2,909 bugs fixed since 5.5, 911 new MTR tests, tripled QA team (400 man years experience) #perconalive

— AlsoSQL (@AlsoSQL) 23 avril 2013

the calm before the storm in Ballroom B. Definitely excited to talk about @opentsdb at #PerconaLive!

— Geoff (@geodbz) 23 avril 2013

@maslett – “The future of databases is distributed.” Important to understand misconceptions of CAP Theorem #perconalive

— Percona (@Percona) 23 avril 2013

Oracle and Tomas Ulin: Will the test cases be re-opened? If 5.6 and 5.7 keeps with non-public tests external dev gets harder… #perconalive

— Jeremy Cole (@jeremycole) 23 avril 2013

We’ll be at @percona Live on April 23 to discuss scaling #MySQL for the web and monitoring MySQL w/ OpenTSDB: percona.com/live/mysql-con…

— Box (@BoxHQ) 22 avril 2013

Oracle has just started the development of #MySQL 5.7 :) #PerconaLive

— Miguel Angel Nieto (@miguel2angel) 23 avril 2013

“Oracle invests in #MySQL like never before” – Tomas Ulin #perconalive

— Percona (@Percona) 23 avril 2013

New today: #MySQL Applier for #Hadoop, enabling real-time event streaming from MySQL to HDFS / Hive: bit.ly/applier_Hadoop

— MySQL_Europe (@MySQL_Europe) 22 avril 2013

Big news! We’ve just announced that we signed a merger agreement with Monty Program, the creators of MariaDB! skysql.com/news-and-event…

— SkySQL Ab (@skysql) 23 avril 2013

I’m continuing to question people #perconalive about their top5 #mysql #performance problems. For most the #1 is their dev ;-) And yours?..
— Dimitri (@dimitrik_fr) 23 avril 2013

It seems that MySQL 5.7 is coming. I have just found these pages dev.mysql.com/doc/refman/5.7… and dev.mysql.com/doc/relnotes/m…
— Giuseppe Maxia (@datacharmer) 23 avril 2013

Continuent #Tungsten Replicator is now 100% Open Source. Read complete press release atbit.ly/ZI9P2M. #perconalive #mysql
— Continuent Tungsten (@Continuent) 22 avril 2013

Announcing #TokuDB v7: Open Source and More! tokutek.com/2013/04/announ… #PerconaLive #MySQL #NewSQL #MariaDB — Tokutek (@tokutek) 22 avril 2013

Slides

Today, I would like to share this list with you.
It is simply a curated transcript of what you might find in the documentation but I’m sure it can help some of you.
 

INTO clause in nested SELECT statements

 
Previously, the parser accepted an INTO clause in nested SELECT statements, which is invalid because such statements must return their results to the outer context. As of MySQL 5.5.3, this syntax is no longer permitted and statements that use it must be changed.
 

Table aliases in DELETE statements

 
In MySQL 5.5.3, several changes were made to alias resolution in multiple-table DELETE statements so that it is no longer possible to have inconsistent or ambiguous table aliases.

In MySQL 5.1.23, alias declarations outside the table_references part of the statement were disallowed for the USING variant of multiple-table DELETE syntax, to reduce the possibility of ambiguous aliases that could lead to ambiguous statements that have unexpected results such as deleting rows from the wrong table.

As of MySQL 5.5.3, alias declarations outside table_references are disallowed for all multiple-table DELETE statements. Alias declarations are permitted only in the table_references part.

Incorrect:

• DELETE FROM t1 AS a2 USING t1 AS a1 INNER JOIN t2 AS a2;
• DELETE t1 AS a2 FROM t1 AS a1 INNER JOIN t2 AS a2;

Correct:

• DELETE FROM t1 USING t1 AS a1 INNER JOIN t2 AS a2;
• DELETE t1 FROM t1 AS a1 INNER JOIN t2 AS a2;

Previously, for alias references in the list of tables from which to delete rows in a multiple-table delete, the default database is used unless one is specified explicitly. For example, if the default database is db1, the following statement does not work because the unqualified alias reference a2 is interpreted as having a database of db1:

• DELETE a1, a2 FROM db1.t1 AS a1 INNER JOIN db2.t2 AS a2 WHERE a1.id=a2.id;

To correctly match an alias that refers to a table outside the default database, you must explicitly qualify the reference with the name of the proper database:

• DELETE a1, db2.a2 FROM db1.t1 AS a1 INNER JOIN db2.t2 AS a2 WHERE a1.id=a2.id;

As of MySQL 5.5.3, alias resolution does not require qualification and alias references should not be qualified with the database name. Qualified names are interpreted as referring to tables, not aliases.

Statements containing alias constructs that are no longer permitted must be rewritten.
 

New reserved words

 
There are several new reserved words in 5.5 what were not reserved in 5.1.
So if you are using any of these as table names, etc., then you’ll need to surround them with backticks (`)

•  GENERAL
• IGNORE_SERVER_IDS
• MASTER_HEARTBEAT_PERIOD
• MAXVALUE
• RESIGNAL
• SIGNAL
• SLOW

FLUSH TABLES and LOCK TABLES

 
As of MySQL 5.5.3, due to work done for Bug #989, FLUSH TABLES is not permitted when there is an active LOCK TABLES … READ.
To provide a workaround for this restriction, FLUSH TABLES has a new variant, FLUSH TABLES tbl_list WITH READ LOCK, that enables tables to be flushed and locked in a single operation.
As a result of this change, applications that previously used this statement sequence to lock and flush tables will fail:

• LOCK TABLES tbl_list READ;
• FLUSH TABLES tbl_list;

Such applications should now use this statement instead:

•  FLUSH TABLES tbl_list WITH READ LOCK;

Fast truncation

 
As of MySQL 5.5.7, InnoDB always uses the fast truncation technique, equivalent to DROP TABLE and CREATE TABLE.
It no longer performs a row-by-row delete for tables with parent-child foreign key relationships.
TRUNCATE TABLE returns an error for such tables.
Modify your SQL to issue DELETE FROM table_name for such tables instead.
 

TIMESTAMP display width

 
In very old versions of MySQL (prior to 4.1), the TIMESTAMP data type supported a display width, which was silently ignored beginning with MySQL 4.1.
This is deprecated in MySQL 5.1, and removed altogether in MySQL 5.5.

The display width is no longer supporter for TIMESTAMP data type in MySQL 5.5
 

Aliases and wildcards

 
Aliases for wildcards (as in SELECT t.* AS 'alias' FROM t) are no longer accepted and result in an error.
Previously, such aliases were ignored silently. (Bug #27249)
 

Scientific notation

 
In addition to these official parts of the MySQL release notes, Sheeri write a post about floats, doubles ans scientific notation between MySQL 5.1 and MySQL 5.5 :

http://blog.mozilla.org/it/2013/01/17/mysql-5-1-vs-mysql-5-5-floats-doubles-and-scientific-notation/

This list is incomplete because I’m sure you have your own tips to share.

Source : http://dev.mysql.com/doc/relnotes/mysql/5.5/en/

Ok, seriously, I would like to share this little observation I made recently when switching to MySQL 5.5 on one slave.
You can see below two graphs for the transactional activity, there is exactly the same volume of update, delete and insert queries :

MySQL 5.1

MySQL 5.5

But the gray area represents the number of commit per second.
I find that I have much more commit with MySQL 5.5, why?
The first question I asked to myself was whether MySQL was telling the truth…

And I had three options to know the truth :

• The com_commit counter : I compared the number of begin and commit during ten minutes
  • MySQL 5.1 : I got much more begin than commit
  • MySQL 5.5 : I got exactly the same result between begin and commit
• The relay logs : In a sample of logs, I compared the number of begin and commit 
  • MySQL 5.1 : I got exactly the same result between begin and commit
  • MySQL 5.5 : I got exactly the same result between begin and commit
• The genaral log : I compared the number of begin and commit during ten minutes
  • MySQL 5.1 : I got exactly the same result between begin and commit
  • MySQL 5.5 : I got exactly the same result between begin and commit

Hum, ok, the com_commit counter want to play with me!

Let’s go in the general log, I had two kinds of commit output :

Query COMMIT
Query COMMIT /* implicit, from Xid_log_event */

So, I called a friend : Hey Google, what is this (f…) Xid_log_event?

http://ftp.nchu.edu.tw/MySQL/sources/doxygen/mysql-5.1/classXid__log__event.html 
http://bugs.mysql.com/bug.php?id=54605

Hum, it smells replication…

Yes, you guessed it, the commit statements from the replication stream are not recorded in the com_commit counter in 5.1.
But the begin statements are recorded in the com_begin counter…

Look at your own slave servers and compare!

I’d make a list of linux system settings to configure a MySQL databases server and share my sources with you.
In return, I would like you to share your sources with the community by publishing your tips in the comments.

swappiness

• This parameter allows to specify how the kernel must manage the memory swap
• Default value : 60 (Range 0 to 100)
• Value to set : 0 (it will swap only to avoid an out of memory condition)
• How to set a new non-persistent value :  sysctl -w vm.swappiness=0
• How to store a new persistent value : add vm.swappiness=0 in the /etc/sysctl.conf file

I/O Scheduler

• The I/O scheduler manages and optimizes priorities of I/O requests
• Default value : device driver dependent
• Range of values : noop / deadline / anticipatory / cfq
• Value to set : noop
• How to set a new persistent value : echo noop >/sys/block/[DEVICE]/queue/scheduler

Mounting options

• These options are set during the filesystem mount process
• Default value : rw
• Value to set ext4 : rw,nosuid,noatime,data=ordered
• Value to set xfs : nobarrier
• How to store a new persistent value : add these options in the /etc/fstab file

I/O queue size

• This queue stores incoming I/O requests
• Default value : 128 (No range)
• Value to set : Hey Dude, you have to test, no magic value for this parameter
• How to set a new persistent value :  echo 100000 > /sys/block/[DEVICE]/queue/nr_requests

Dirty ratio

• These settings are used to tune the VM subsystem about dirty data
• Default value : 10 and 20
• Value to set : Again, you should test. You can try 5 and 60 to begin
• How to set a new non-persistent value :
  • echo 5 > /proc/sys/vm/dirty_background_ratio
  • echo 60 > /proc/sys/vm/dirty_ratio
• How to store a new persistent value : Add these parameters to the /etc/sysctl.conf file
  • vm.dirty_background_ratio = 5
  • vm.dirty_ratio = 60

NUMA Architecture

• Memory allocation management for multiple processors architecture
• You should read this : http://blog.jcole.us/2010/09/28/mysql-swap-insanity-and-the-numa-architecture/
• And test…

Note that all of these tips focus on optimizing I/O.
The first three tips can be considered as really interesting.
I recommend you to read the sources before any change.

Remember to test every changes before to put them in production.

Now, let us know how you setup your system for MySQL.

Sources :
- http://en.wikipedia.org/wiki/Swappiness
- http://yoshinorimatsunobu.blogspot.fr/2009/04/linux-io-scheduler-queue-size-and.html
- http://rackerhacker.com/2008/08/07/reduce-disk-io-for-small-reads-using-memory
- http://assets.en.oreilly.com/1/event/21/Mastering%20the%20Art%20of%20Indexing%20Presentation.pdf
- http://cdn.oreillystatic.com/en/assets/1/event/56/Linux%20and%20H_W%20optimizations%20for%20MySQL%20Presentation.pdf
- http://www.mysqlperformanceblog.com/2013/01/03/is-there-a-room-for-more-mysql-io-optimization/
- http://www.percona.com/files/presentations/UC2011-MySQL-and-SSD-Usage-Patterns.pdf
- http://blog.jcole.us/2010/09/28/mysql-swap-insanity-and-the-numa-architecture/
- http://blog.jcole.us/2012/04/16/a-brief-update-on-numa-and-mysql/

Now, I tried this query on a MariaDB 5.5 server and I had a surprise :

The result was a bit strange, with negative or null values.

I’ve just had these server for few hours in my hands and I had no more time to analyze the situation.
I assume that the subquery optimisations in MariaDB can be involve here but it’s just an assumption.

Does anyone encountered the same issue? (with MariaDB or other distro)

You can find some of the slides on [Plus], enjoy! :

If you would like to add your slides, post a comment with the link.
And remember to visit this page for more slides about MySQL : http://www.mysqlplus.net/mysql-docs/

I asked you to vote for what you used in 2012 and you’ve voted with your heart.
Here are the final results, congrats to the lucky guys and teams :

The most useful blogs in 2012 :

1. MySQL Performance Blog
2. The MariaDB Blog
3. SkySQL Blog

Ok, the Percona team members provides the best technical blog about MySQL (and more), this year again. Of course, this blog is very useful and interesting, I recommend to read the comments too, they are often very informative.
There is a lot of work behind this blog, so, its popularity is deserved.

But wait, I’m sure these 3 teams (Percona + MariaDB + SkySQL) represents 80% of the whole MySQL DBAs around the world.
So, let me congratulate independent bloggers for their active involvement and for their sincerity.

The most useful forum in 2012 :

1. Stackoverflow.com
   
2. Twitter.com
3. Forums.mysql.com

I really like stackoverflow, not only for my MySQL issues, activity on these forums is impressive!
And I’m not surprised to see Twitter in second position, I’ve already written about how I use Twitter.
My advice about Twitter : choose your friends sparingly (if you would read all the tweets that you receive every day)

best MySQL event in 2012 :

1. MySQL Conference & Expo
2. Percona Live London
3. FOSDEM

I attended the last two editions of Percona Live at London and these events were incredibly good.
I assume that the MySQL Conference was really interesting but too far for poor European guys…

I was at FOSDEM for the first time this year and it was very exciting. I was very glad to see Percona, MariaDB and Oracle together.
If you’ve never been at FOSDEM, I recommend you to join us next year, this is truly a magical event!

What would you like to test in 2013?

1. Galera Replication
2. MySQL 5.6
3. MariaDB 10 

Galera Replication was popularized by Percona and MariaDB last year.
But the guys from Codership works on this project over many years. This is a very ambitious project that deserves to be tested.
And it has become easier than ever since Galera was packaged by Percona and MariaDB.

MySQL 5.6 is now GA! It’s time to forget your brand new MySQL 5.5 upgrades…

MariaDB is now part of a foundation that ensures the open source nature of MySQL.
Now, you have to make a choice between MySQL 5.6, Percona server 5.6 (not yet released) and MariaDB 10.
However, I’m still a bit skeptical about the ambiguous Monty’s declarations on the compatibility between MariaDB and the future releases of Oracle MySQL.
But it’s only my opinion and don’t undermine the great job provided  by the Monty program team on MariaDB.

Thank you again for your participation, find all the results here.
And I hope to see you in real life this year…

 
This year again, be sure that FOSDEM will be the place to be in February!

Do you have any doubts? Really ? Dude, repeat after me :

1. Free event
2. During a week-end
3. Beer
4. 5000+ open source geeks
5. Beer
6. MySQL and Friends devroom
7. NoSQL devroom
8. No registration needed (open source man!)

Ok, that sounds good?

Well, here are the informations to attend this terrific event :

• How to register? : Are you kidding me?
• When : 2 & 3 February 2013 (Hurry up guys!)
• Where : Brussels (beers!!!)
• Website : https://fosdem.org/2013/

Max and I will be at FOSDEM for the first time this year.
Hope to see you there

PS1 : If you didn’t vote for the [Plus] Readers Choice 2012 yet, do it now!
PS2 : And if you want to stay on the move, ask for these cute stickers, your laptop will love them!